diff --git a/.changeset/canonical-formats-adopter-feedback.md b/.changeset/canonical-formats-adopter-feedback.md
new file mode 100644
index 0000000000..8b262f79cc
--- /dev/null
+++ b/.changeset/canonical-formats-adopter-feedback.md
@@ -0,0 +1,17 @@
+---
+"adcontextprotocol": minor
+---
+
+canonical-formats: five adopter-flagged additions before lock. Each surfaces guidance that was implicit in the spec but not findable; one resolves a normative silence.
+
+**1. "What `format_kind` is NOT for" decision rule** (canonical-formats.mdx). Adopters seeing the broadcast / DOOH / generative annotations were tempted to propose `format_kind: dooh_image` or `format_kind: broadcast_video` in 3.2. New section enumerates the six axes (creative type / production model / slot shape / channel / measurement / targeting) and the rule of thumb: new `format_kind` ONLY when the creative ASSET is structurally different. All 50 ad formats in the catalog ship via this rule; zero new canonicals added for broadcast / DOOH / native / generative.
+
+**2. `slots_override` authoring decision rule** (canonical-formats.mdx). When to use it vs leave it off was implicit across the four annotation patterns. New section + table makes it explicit: would a buyer composing the manifest list **different assets** vs the canonical's defaults? Yes → `slots_override`. No → omit. Worked cases: IAB MREC (default), native standard (override), DOOH (default), broadcast (default), generative (override), host-read podcast (override).
+
+**3. End-to-end `adagents.json` fetch flow worked example** (canonical-formats.mdx). The pieces were documented separately (publisher catalog, property scoping, capability_id resolution, community-mirror fallback, supersession). New section walks the full buyer journey in order: `Product` with `publisher_properties` → fetch `<domain>/.well-known/adagents.json` → fall back to AAO mirror on 404 → check `superseded_by` → scope `formats[]` by `applies_to_property_ids` → resolve `capability_id` against same-file `formats[]`. Concrete payload sequence included.
+
+**4. Multi-size fan-out normative decision** (canonical-formats.mdx + error code prose). The spec was silent on whether SDKs MAY fan out a multi-size v2 declaration to N v1 format_ids via catalog lookup. Resolved as MAY-do non-normative: SDKs without catalog access emit only seller-asserted refs (the conservative wire shape, default normative behavior); SDKs with catalog access MAY synthesize the missing per-size refs. Either way, `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` MUST fire as a transparency advisory; `error.details.synthesized_refs` lists catalog-resolved entries when fan-out is in play. Two SDKs processing the same input may produce different `format_ids[]` lengths, but the advisory keeps consumers in sync.
+
+**5. `format_schema` fetch-contract test fixtures** (static/examples/format-schemas/). 14 paired positive + negative test vectors covering all 7 failure-mode categories per the normative contract: digest verification, transport (https-only / redirect / oversize), SSRF (RFC 1918 / metadata endpoint), `$ref` sandboxing (cross-origin / depth-exceeded), schema-compile budget (catastrophic regex), schema validity (body is JSON but not a valid schema), graceful degradation (404 with/without cache). Each fixture documents the `setup` to simulate, the `expected_outcome`, the `expected_error_code`, and the rationale linking back to the contract clause. README at `static/examples/format-schemas/README.md` documents shape and usage. Cross-SDK conformance harness tracked as follow-up #4699.
+
+Validation: schema build clean, 14 canonical fixtures + 28 negative fixtures (was 19) + 50-entry catalog convention lint all green.
diff --git a/.changeset/canonical-formats.md b/.changeset/canonical-formats.md
new file mode 100644
index 0000000000..464d53726f
--- /dev/null
+++ b/.changeset/canonical-formats.md
@@ -0,0 +1,47 @@
+---
+"adcontextprotocol": minor
+---
+
+**Canonical formats (AdCP 3.1).** v2 introduces a structured creative-format vocabulary that buyers and sellers can validate against without per-seller integration code. 13 canonical `format_kind` values (image, html5, display_tag, image_carousel, video_hosted, video_vast, audio_hosted, audio_daast, sponsored_placement, native_in_feed, responsive_creative, agent_placement, custom) with a two-axis model: `format_kind` names the creative TYPE; `asset_source` names the production model (buyer_uploaded / publisher_host_recorded / seller_pre_rendered_from_brief / seller_human_designed / agent_synthesized). Products carry `format_options[]` declarations narrowing a canonical with `params`, `slots`, `applies_to_channels`, optional `capability_id` for multi-format routing, and optional `experimental` flag. The full reference is at `docs/creative/canonical-formats.mdx`.
+
+**Wire-shape details adopters care about:**
+
+- `v1_format_ref` is ALWAYS an array of `{agent_url, id}` entries — single-ref is `[{...}]`. Multi-size declarations carry one ref per size in `params.sizes[]`. The `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` error code surfaces when ref count < sizes[] count.
+- v1 catalog's `canonical:` annotation is ALWAYS an object — minimal `{ "kind": "image" }`, rich `{ "kind", "asset_source", "slots_override" }`. The object form is what lets the 8 generative catalog entries (`display_*_generative`) project losslessly to v2: buyer ships a text prompt, not image bytes.
+- Display canonicals (`image`, `html5`, `display_tag`) support three size modes (mutex-enforced at schema layer): fixed `width+height`, multi-size `sizes: [{w,h}]` (mirrors OpenRTB `banner.format[]`), responsive `min_width/max_width/min_height/max_height`. The same product can carry N format_options across the three modes.
+- `ProductFormatDeclaration.canonical_formats_only: true` is the v2-only marker (mutex with `v1_format_ref`).
+- `format_kind: "custom"` requires `format_shape` (vocabulary entry) + `format_schema` (URI+digest) and either `canonical_formats_only: true` OR `v1_format_ref`.
+
+**Publisher catalog (`adagents.json formats[]`).** Publishers declare their format support once via top-level `formats[]` (with optional `applies_to_property_ids` / `applies_to_property_tags` scoping). Placements reference declarations by `capability_id`. For platforms that haven't adopted AdCP (Meta, TikTok, etc.), AAO publishes community-maintained adagents.json at `creative.adcontextprotocol.org/translated/<platform>/adagents.json`; `superseded_by` field signals platform-adoption cutover. New media-buy filters `list_creative_formats(publisher_domain, property_id)` answer "what formats does this publisher accept?" with a normative resolution chain (publisher hosted → AAO mirror → agent-derived from products) and a response `source` field labeling which tier produced the list.
+
+**Where each piece of metadata lives (the "no new canonical" pattern).** Before reaching for a new canonical, the spec checks: production model → `asset_source`; slot shape → `slots_override`; channel → `applies_to_channels`; tracking / measurement → `sync_event_sources` / `event_log`. New canonical only when the CREATIVE ASSET is structurally different. Applied: generative, broadcast TV, DOOH, native all stay on existing canonicals via sibling refinement. Conversion pixels (Meta Pixel, GA4) explicitly belong on event_log, NOT on `platform_extensions` of a creative format.
+
+**Coverage at GA.** 50/50 ad formats in the AAO catalog annotated with the projection-ref object form. 7 UI scaffolding entries (`product_card_*`, `format_card_*`, `proposal_card_*`, `native_product_card`) split into `ui-element-formats.json` — they're agent-interface widgets, not ad formats; `list_creative_formats` returns them so consumers can resolve by `format_id`, but they never project to ad canonicals.
+
+**Error codes added** (all surfaced via response `errors[]` augmentation; non-fatal advisories): `FORMAT_PROJECTION_FAILED`, `FORMAT_DECLARATION_DIVERGENT`, `FORMAT_DECLARATION_V1_AMBIGUOUS`, `FORMAT_CAPABILITY_UNRESOLVED`, `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE`, `PIXEL_TRACKER_LOSSY_DOWNGRADE`, `PIXEL_TRACKER_UPGRADE_INFERRED`.
+
+**Cross-version pixel_tracker contract (normative for SDK auto-negotiation)**: when a 3.1 buyer SDK talks to a 3.0.x seller that doesn't know `pixel_tracker`, the SDK MUST downgrade to v1 `{asset_type: url, url_type: tracker_pixel}` shape and emit `PIXEL_TRACKER_LOSSY_DOWNGRADE` with per-field details. Conversely a 3.1 SDK reading v1 trackers MUST upgrade by inferring event/method from `asset_id` conventions and emit `PIXEL_TRACKER_UPGRADE_INFERRED`. Both directions are lossy-with-advisory — no REFUSE branch, even for `method: js` (v1 sellers fire the URL as a GET; counter-based measurement increments, but JS-execution-dependent measurement like OMID-style verification won't run). Buyer-side decision per asset: accept the loss or route to a 3.1-capable seller. Full bidirectional mapping table documented in `pixel-tracker-asset.json` description.
+
+**Renderer-fired pixel tracker asset type (#4706)**: new `pixel_tracker` asset type at `static/schemas/source/core/assets/pixel-tracker-asset.json` — the generic web-pixel tracker primitive, applies to any web-rendered canonical (image, html5, image_carousel, responsive_creative, sponsored_placement, native_*, plus non-VAST/DAAST events on video_hosted/audio_hosted). Discriminated union with `event` (impression, viewable_mrc_50, viewable_mrc_100, viewable_video_50, click, custom), `method` (img, js), `url` (uri-template with universal-macros support), and `custom_event_name` (required when event is `custom`). Discriminator shape and event/method enums formalized in IAB OpenRTB Native 1.2 (`imptrackers[]` / `jstracker` / `eventtrackers[]` / `link.clicktrackers[]`). Scope is RENDERER-FIRED trackers — conversion pixels (Meta Pixel, GA4, server-side postbacks) stay on `sync_event_sources` / `event_log` per the format-vs-event_log boundary documented in canonical-formats.mdx. Formats with format-specific tracker structures keep their own primitives: `vast_tracker` (VAST `<TrackingEvents>`), `daast_tracker` (DAAST parity).
+
+**Catalog tracker upgrade**: 45 ad-format payload entries in `server/src/creative-agent/reference-formats.json` previously carrying `impression_tracker` as `asset_type: "url"` upgraded to `asset_type: "pixel_tracker"` with `event: "impression"` + `method: "img"` — display / native / dooh / video_hosted / audio_hosted families all benefit. Plus 4 `slots_override` declarations on `native_standard` / `native_content` reshaped to use `pixel_tracker` for impression and click trackers. To match real measurement plans (impression + viewability + click trackers are commonly attached together), 90 additional optional slots added across the 45 web-rendered entries: each now carries `viewability_tracker` (`event: viewable_mrc_50`) and `click_tracker` (`event: click`) as optional `pixel_tracker` slots. Buyer populates only the trackers their measurement plan declares; absent slots are skipped. New vocabulary entries: `impression_tracker`, `click_tracker`, `viewability_tracker` in asset-group-vocabulary, all mapping to `asset_type: pixel_tracker`.
+
+**`pixel_tracker.event` enum mirrors IAB Native event-type registry**: 5 standardized event values plus `click` and `custom`. Maps 1:1 to IAB OpenRTB Native 1.2: `impression` (1), `viewable_mrc_50` (2), `viewable_mrc_100` (3), `viewable_video_50` (4), `audible_video_complete` (500). `audible_video_complete` is distinct from `viewable_video_50` — the former is 100% completion with audio on; the latter is 50% pixels for ≥2 seconds with audio on. Meaningful on non-VAST video (Meta Reels, YouTube Shorts, TikTok Spark) where audible-complete is measured but VAST `<TrackingEvents>` isn't the wire format.
+
+**Negative-fixture coverage**: 10 new test vectors for `pixel_tracker` in `tests/canonical-negative-fixtures.test.cjs` covering valid shapes (impression img / impression js / viewable_mrc_50 / click / audible_video_complete / custom-with-name) and the rejection paths (custom without `custom_event_name`, non-custom with `custom_event_name`, invalid event enum, invalid method enum). Total negative-fixture count goes from 28 → 38.
+
+**Other adopter-facing additions:**
+
+- `ProductFormatDeclaration.seller_preference: "preferred" | "accepted" | "discouraged"` — soft routing hint on multi-format products.
+- `placement-definition.json format_options[]` (capability_id reference OR inline) with same-file resolution scope.
+- Convention lint at `tests/canonical-format-conventions.test.cjs` enforces: object-form `canonical:`, array-form `v1_format_ref[]`, size-mode mutex, AAO-mirror URL convention, slot/param consistency.
+
+**Round-2 adopter feedback (Pia Malovrh / Nastassia Fulconis, 2026-05-18 Slack):**
+
+- **`native_in_feed` canonical added.** 13th `format_kind` covering IAB OpenRTB Native 1.2 in-feed native ads, content-recommendation widgets (Taboola, Outbrain, Yahoo Native, AdMob Native), and publisher in-feed sponsored placements without catalog dependency. Slots map 1:1 to IAB Native asset types (`title`, `body_text`, `main_image`, `icon`, `cta`, `advertiser_name`, `sponsored_label`, `landing_page_url`, plus renderer-fired `pixel_tracker` trackers). Routing answer: buyer agents reading `native_in_feed` know to assemble title+image+body+CTA; reading `sponsored_placement` know to attach a catalog feed. Defaults to non-experimental (IAB Native 1.2 contract is well-established).
+- **`sponsored_placement` narrowed.** Canonical is now normatively catalog-keyed retail-media ONLY: REQUIRES `source_catalog` slot. Schema description explicitly excludes IAB in-feed native, content-recommendation, PMax-style algorithmic surfaces, and single-image/video creative — those route elsewhere. Earlier broader framing failed buyer-agent routing (buyer reading `sponsored_placement` couldn't disambiguate Amazon SP from Taboola).
+- **`scenes` → `video_brief` rename.** Renamed `static/schemas/source/creative/scenes.json` → `creative/video-brief.json` (`$id: /schemas/creative/video-brief.json`), wrapper field `scenes[]` → `segments[]`, per-segment `description` → `prompt`. The shape was always a structured generation brief (no camera direction, shot type, mood, or reference attachments) — the rename calls it that. asset_group_id `scenes` → `video_brief` (with `scenes`, `storyboard`, `shot_brief` as aliases). Distinct from `creative_brief` (free-form text); `video_brief` is the structured timed-prompt form. Buyers wanting visual-direction surface still attach `reference-asset.json` with `purpose: storyboard`.
+- **`seller_preference` semantics clarified.** Schema description and `ProductFormatDeclaration` description now state normatively that `format_options[]` is the closed set of accepted formats for a product — sellers MUST reject `create_media_buy` requests targeting any `format_kind` outside that set. `seller_preference` is a soft ranking hint WITHIN the accepted set, NOT an enforcement axis. There is intentionally no `required` enum value; the closed-set rule already handles "this is the only format that works" (list one entry → that's the set). Pia's "won't work vs please don't" distinction is resolved structurally rather than via enum proliferation.
+- **Registry two-tier boundary documented; platform-specific IDs removed.** Dropped `youtube_video_id` and `pin_id` from `asset-group-vocabulary.json`. Added normative paragraph: the canonical vocabulary is the IAB-aligned portable tier; platform-specific asset identifiers (TikTok video IDs, Snap attachment IDs, Meta Advantage+ creative IDs, etc.) belong on the canonical's `platform_extensions[]` (URI+digest reference to the platform's extension schema). Earlier draft set precedent for every platform's identifier vocabulary leaking into the canonical registry — explicitly reversed before GA.
+
+**Resolves** #4148 (canonical-formats vocabulary), #4620 (publisher-scoped catalogs), #4652 (.adcp placeholder cleanup), #4689 (catalog generative deannotation). Coordinated with adcp-client #1815 (SDK v1↔v2 projection) and adcp-go (catalog consumer).
diff --git a/.changeset/v2-phase1-vocab-scenes-zip.md b/.changeset/v2-phase1-vocab-scenes-zip.md
new file mode 100644
index 0000000000..675cdd892d
--- /dev/null
+++ b/.changeset/v2-phase1-vocab-scenes-zip.md
@@ -0,0 +1,30 @@
+---
+"adcontextprotocol": minor
+---
+
+feat(creative): v2 Phase 1 — asset_group_id vocabulary registry, `scenes` schema, `zip` asset type, video/audio mdx asset_type fixes
+
+First PR implementing the v2 creative formats RFC (#3305). Backwards-compatible additions only — no v1 producers are affected. Minor bump because this introduces new schemas (`asset-group-vocabulary.json`, `scenes.json`, `zip-asset.json`), which are additive features rather than bug fixes.
+
+**New schemas:**
+
+- `static/schemas/source/core/asset-group-vocabulary.json` — canonical registry of `asset_group_id` values (the seven existing catalog vocab entries plus 12 audit-driven additions: `video_vertical`, `video_horizontal`, `audio`, `companion_image`, `companion_banner`, `brand_name`, `body_text`, `cards`, `landing_page_url`, `privacy_policy_url`, `youtube_video_id`, `pin_id`). Includes the `landing_page_url` aliases canonicalizing six different field names today (`click_url`, `link`, `final_url`, `link_url`, `click_through_url`, `landing_url`). Non-canonical IDs remain valid for platform-specific extensions; validators MAY soft-warn on non-canonical usage.
+
+- `static/schemas/source/creative/scenes.json` — typed scene-by-scene structure used as input to `build_creative` for generative video platforms. Each scene has `order`, `duration_ms`, `description`, optional `vo` and `caption`. Renamed from "storyboard" to avoid collision with the testing-harness storyboard concept; description disambiguates from `reference-asset.json` `purpose: "storyboard"` (which describes a reference asset, not a structured plan).
+
+- `static/schemas/source/core/assets/zip-asset.json` — new asset type for bundled creatives delivered as zip archives (HTML5 banners with index.html + CSS + JS + images, MRAID-compatible interactive ads). Carries `url`, optional `max_file_size_kb`, `entry_point`, `allowed_inner_extensions`, `backup_image_url`, and SHA-256 `digest` for integrity. Distinct from inline HTML (`html` asset) and from third-party tag URLs (`url` asset with appropriate `url_type`).
+
+**Registry updates:**
+
+- `static/schemas/source/creative/asset-types/index.json` — added `zip` entry pointing at the new schema
+- `static/schemas/source/core/format.json` — added `IndividualZipAsset` and `GroupZipAsset` branches to the format declaration oneOf
+- `static/schemas/source/core/offering-asset-group.json`, `creative-manifest.json`, `creative-asset.json`, `creative/list-creatives-response.json` — added `zip-asset.json` to manifest/asset-group oneOf branches so manifests can carry zip assets
+
+**Doc fixes:**
+
+- `docs/creative/channels/video.mdx` — corrected three format-definition examples that used `asset_type: "url"` + `asset_role: "vast_url"` / `"vpaid_url"`, contradicting the schema-correct `asset_type: "vast"` used elsewhere in the same file. Updated VPAID examples to use `asset_type: "vast"` with `vpaid_enabled: true` in requirements.
+- `docs/creative/channels/audio.mdx:200` — same bug pattern: `asset_type: "url"` for what should be a VAST audio tag. Corrected to `asset_type: "vast"` with `delivery_type: "url"`; renamed slot key from `vast_url` to `vast_tag` for clarity.
+
+**Why minor (not patch):** new schemas and a new asset type are additive features — patch is reserved for bug fixes only. **Why not major:** no breaking changes; v1 producers and consumers continue to work unchanged. The new `zip` asset type is purely additive — receivers that don't recognize it ignore it via standard discriminator-mismatch handling.
+
+Tracks #3305 (v2 RFC). Phase 1 lays foundational primitives; subsequent phases build the canonical format catalog, `ProductFormatDeclaration` schema, and tools on top of these primitives.
diff --git a/docs/building/by-layer/L1/security.mdx b/docs/building/by-layer/L1/security.mdx
index d7c251bfa1..2b3fe3ebec 100644
--- a/docs/building/by-layer/L1/security.mdx
+++ b/docs/building/by-layer/L1/security.mdx
@@ -1583,7 +1583,7 @@ export async function verifyAdcpRequestSignature(req: Request, ctx: {
   const { jwk } = await ctx.resolveJwk(parsed.keyid!); // throws _key_unknown
   // 8: key purpose
   const j = jwk as any;
-  if (j.use !== "sig" || !Array.isArray(j.key_ops) || !j.key_ops.includes("verify") || j.adcp_use !== "request-signing") {
+  if (j.use !== "sig" || !Array.isArray(j.key_ops) || !j.key_ops.includes("verify") || j.example_use !== "request-signing") {
     throw new RequestSignatureError("request_signature_key_purpose_invalid");
   }
   // 9: revocation (BEFORE crypto verify)
diff --git a/docs/creative/asset-types.mdx b/docs/creative/asset-types.mdx
index 74ec9e9123..8e10fe260b 100644
--- a/docs/creative/asset-types.mdx
+++ b/docs/creative/asset-types.mdx
@@ -4,11 +4,40 @@ description: "AdCP asset types define standardized properties for images, video,
 "og:title": "AdCP — Asset Types"
 ---
 
+> **Canonical-formats readers**: this page describes asset types and their payload shapes — the same in v1 and the canonical-formats path. For how assets map to canonical-format slots via `asset_group_id`, see [canonical-formats](/docs/creative/canonical-formats) and the [migration guide](/docs/creative/canonical-formats-migration). v1 uses `asset_id` + `asset_role`; canonical formats use `asset_group_id` referencing the canonical vocabulary registry. Both paths use the same asset payload schemas — only the slot-key vocabulary differs.
 
 Creative formats in AdCP use standardized asset types with well-defined properties. Assets are the discrete, typed building blocks used by formats to define requirements and by manifests to supply concrete values.
 
 Standardizing asset types ensures consistency across formats and makes requirements easier for buyers and systems to understand.
 
+## Asset types in v2
+
+The full set of asset types valid in a v2 format `slots` declaration's `asset_type` field:
+
+| asset_type | What it carries | Where defined |
+|---|---|---|
+| `image` | Image file (jpg/png/gif/webp/svg) | `/schemas/core/assets/image-asset.json` |
+| `video` | Video file (mp4/webm/mov) | `/schemas/core/assets/video-asset.json` |
+| `audio` | Audio file (mp3/aac/wav) | `/schemas/core/assets/audio-asset.json` |
+| `text` | Plain text (headline, body, script) | `/schemas/core/assets/text-asset.json` |
+| `markdown` | Markdown text | `/schemas/core/assets/markdown-asset.json` |
+| `url` | URL with `url_type` discriminator (clickthrough, tracker_pixel, third-party tag) | `/schemas/core/assets/url-asset.json` |
+| `html` | Inline HTML | `/schemas/core/assets/html-asset.json` |
+| `css` | CSS rules | `/schemas/core/assets/css-asset.json` |
+| `javascript` | JavaScript | `/schemas/core/assets/javascript-asset.json` |
+| `vast` | VAST tag (URL or inline XML), VAST 2.x-4.x | `/schemas/core/assets/vast-asset.json` |
+| `daast` | DAAST tag (URL or inline XML), 1.0-1.1 | `/schemas/core/assets/daast-asset.json` |
+| `webhook` | Webhook URL for async creative production | `/schemas/core/assets/webhook-asset.json` |
+| `brief` | Free-text creative brief (input to generative production) | `/schemas/core/assets/brief-asset.json` |
+| `catalog` | Reference to a synced catalog (sponsored_placement) | `/schemas/core/assets/catalog-asset.json` |
+| `zip` | Zip archive (HTML5 banner bundle) | `/schemas/core/assets/zip-asset.json` |
+| `vast_tracker` | Single VAST `Tracking` event URL (decomposed) | `/schemas/core/assets/vast-tracker-asset.json` |
+| `daast_tracker` | Single DAAST `Tracking` event URL (decomposed) | `/schemas/core/assets/daast-tracker-asset.json` |
+| `pixel_tracker` | Renderer-fired HTTP tracker (image pixel or JS include) for any web-rendered canonical. `event` (impression / viewable_mrc_* / viewable_video_50 / audible_video_complete / click / custom) × `method` (img / js). Maps to IAB OpenRTB Native 1.2 `imptrackers[]` / `jstracker` / `eventtrackers[]` / `link.clicktrackers[]` event-type registry (types 1, 2, 3, 4, 500) | `/schemas/core/assets/pixel-tracker-asset.json` |
+| `object` | Structured object (image_carousel `cards`, `video_brief` for generative video) — sub-shape declared by the canonical | (no standalone schema; per-canonical sub-shape) |
+
+In a v2 manifest's `assets` map, the **slot key** is the canonical's `asset_group_id` (e.g., `image_main`, `video_main`, `script`, `cards`, `landing_page_url`) and the **value** carries the matching asset payload with its `asset_type` discriminator. The format declaration's `slots[].asset_type` tells the validator which payload schema applies.
+
 ## Important: Payload vs Requirements
 
 For payload schemas (the structure of the actual asset data supplied in creative manifests), see:
@@ -186,6 +215,8 @@ In format requirements, `role` declares what the URL slot is for:
 
 `role` enum: `clickthrough`, `landing_page`, `impression_tracker`, `click_tracker`, `viewability_tracker`, `third_party_tracker`.
 
+> **For canonical-formats v2: prefer `pixel_tracker` over `url` + `url_type: tracker_pixel`** for renderer-fired measurement trackers on any web-rendered canonical (image, html5, image_carousel, responsive_creative, sponsored_placement, native, video_hosted non-VAST events, audio_hosted non-DAAST events). The legacy `url` shape remains valid for VAST/DAAST `<Impression>` URLs and for backward compatibility; new authoring SHOULD use the typed `pixel_tracker` form because it carries the event + method semantics that bare URLs lose. See the dedicated section below.
+
 #### Other URL-asset-requirements properties
 
 - `protocols`: Allowed schemes (`https`, `http`)
@@ -397,6 +428,36 @@ Audio-side analogue of `vast_tracker`: a single URL bound to a DAAST `TrackingEv
 - `offset`: Required for `daast_event: "progress"` (DAAST 1.1 §3.2.4.3). Same format as VAST 4.2 `Tracking@offset`. Negative offsets are NOT permitted.
 - `target`: Which DAAST creative element scopes this tracker — `linear` (default, DAAST 1.1 §3.2.1.7) or `companion` (DAAST 1.1 §3.2.2.7, where the only valid event is `creativeView`). DAAST has no `<NonLinearAds>` element — audio is linear or accompanied by a visual companion.
 
+### Pixel Tracker Asset
+
+Renderer-fired HTTP tracker — image pixel or JavaScript include — bound to a measurement event. Applies to any **web-rendered** canonical format (image, html5, image_carousel, responsive_creative, sponsored_placement, native_*, plus non-VAST/DAAST events on video_hosted / audio_hosted). Format-specific tracker primitives (`vast_tracker`, `daast_tracker`) remain the right shape for VAST/DAAST event semantics; `display_tag` is opaque (third-party served).
+
+**Example:**
+```json
+{
+  "asset_type": "pixel_tracker",
+  "event": "impression",
+  "method": "img",
+  "url": "https://measurement.example.com/imp?cb={CACHEBUSTER}&cid={CREATIVE_ID}"
+}
+```
+
+**Properties:**
+- `event`: `impression` | `viewable_mrc_50` | `viewable_mrc_100` | `viewable_video_50` | `audible_video_complete` | `click` | `custom`. Event enum mirrors IAB OpenRTB Native 1.2 event-type registry (types 1, 2, 3, 4, 500). `audible_video_complete` is distinct from `viewable_video_50` — the former is full-completion with audio on; the latter is 50% pixels for ≥2 seconds with audio on. Meaningful on non-VAST video formats (Meta Reels, YouTube Shorts, TikTok Spark); VAST formats use `vast_tracker` with `vast_event: complete` instead.
+- `method`: `img` (fired as `<img>` pixel) or `js` (fired as `<script>` include). Matches IAB Native 1.2 method enum (1=img, 2=js). Default `img`. Sellers without JS-tracker support MUST reject `method: js` declarations at sync_creatives time.
+- `url`: Tracker URL fired when `event` occurs. May carry AdCP universal macros.
+- `custom_event_name`: REQUIRED when `event: custom`, forbidden otherwise (if/then enforced at the schema layer). Adopter-defined event name; sellers without registered handling MUST silently no-op rather than reject.
+
+**Maps to IAB OpenRTB Native 1.2:**
+- `imptrackers[]` → `pixel_tracker` with `event: impression`, `method: img`
+- `jstracker` → `pixel_tracker` with `event: impression`, `method: js`
+- `eventtrackers[]` → `pixel_tracker` per entry; `event` mapped from the IAB enum
+- `link.clicktrackers[]` → `pixel_tracker` with `event: click`, `method: img` (click destinations remain on `landing_page_url`)
+
+**Scope boundary (normative).** `pixel_tracker` covers RENDERER-FIRED trackers only — measurement events the ad's serving template invokes when the user sees, views, or clicks the creative. Conversion pixels that fire on the advertiser's site after the click (Meta Pixel, GA4 server-side, custom postbacks) MUST be modeled via `sync_event_sources` / `event_log` — they are campaign-scoped, not creative-asset-scoped.
+
+**Multi-tracker pattern.** Real measurement plans routinely attach 2-4 trackers per creative (one impression img + one impression js for vendor redundancy, one MRC viewable, sometimes a click pixel). Catalog entries that want to expose all of these declare separate slots (`impression_tracker`, `viewability_tracker`, `click_tracker`) — see `asset-group-vocabulary.json`. Buyers populate only the slots they have trackers for; absent slots are skipped.
+
 ## Creative / Sales Agent Boundary (VAST Assembly)
 
 AdCP separates **creative agents** (produce the assets a creative is made of) from **sales agents** (assemble those assets into the serving format the ad server expects). For VAST and DAAST, the boundary is normative:
diff --git a/docs/creative/canonical-formats-migration.mdx b/docs/creative/canonical-formats-migration.mdx
new file mode 100644
index 0000000000..f34662ca0a
--- /dev/null
+++ b/docs/creative/canonical-formats-migration.mdx
@@ -0,0 +1,573 @@
+---
+title: Migration to Canonical Formats
+description: "Concrete migration paths for sellers, creative agents, buyers, and tooling moving from v1 named formats to canonical-format product-bound declarations."
+"og:title": "AdCP — Canonical Formats Migration"
+testable: true
+---
+
+# Migration: v1 named formats → Canonical Formats
+
+This guide walks through the shift from v1 named formats (`format_id` as `{ agent_url, id }` referencing a separately-defined format file) to canonical-format product-bound declarations introduced by [RFC #3305](https://github.com/adcontextprotocol/adcp/issues/3305). v1 named formats remain a first-class path through 4.x; canonical formats are the new path, opt-in indefinitely.
+
+For the architecture, read [`canonical-formats`](/docs/creative/canonical-formats) first. This page is just the migration mechanics.
+
+> *Naming note*: The v1↔v2 terminology used throughout this page describes the two format-authoring models — `format_ids` (legacy, v1) vs `format_options` (canonical formats, v2). It does NOT refer to AdCP-the-protocol's version (currently 3.x). The "v2" path is also called the canonical-formats path; both phrasings mean the same thing.
+
+## What stays unchanged
+
+Most of AdCP doesn't change. v2 builds on the existing primitives:
+
+- All asset primitive schemas (`image-asset.json`, `video-asset.json`, `audio-asset.json`, `vast-asset.json`, `daast-asset.json`) — unchanged
+- Catalog and offering schemas — unchanged
+- Manifest envelope shape (`creative-manifest.json` keyed by `assets` map) — unchanged
+- Response envelopes, error schemas, common types — unchanged
+- v1 named formats (`format.json` with compound `format_id`) — still supported through 4.x
+- v1 `list_creative_formats` tool — deprecated but functional through 4.x; removed at 5.0
+- All existing producers and consumers — continue to work without changes
+
+## Side-by-side: a v1 named format → v2 product format declaration
+
+### v1 — separate format file referenced by product
+
+```json test=false
+// formats/meta_reels.json
+{
+  "format_id": { "agent_url": "https://creative.adcontextprotocol.org", "id": "meta_reels" },
+  "name": "Meta Reels",
+  "type": "video",
+  "assets": [
+    {
+      "asset_id": "video_file",
+      "asset_type": "video",
+      "asset_role": "hero_video",
+      "item_type": "individual",
+      "required": true,
+      "requirements": {
+        "min_duration_ms": 3000,
+        "max_duration_ms": 90000,
+        "aspect_ratio": "9:16",
+        "min_width": 1080,
+        "min_height": 1920,
+        "containers": ["mp4"],
+        "codecs": ["h264"]
+      }
+    }
+  ]
+}
+
+// products/meta_reels_us.json
+{
+  "product_id": "meta_reels_us",
+  "name": "Meta Reels — United States",
+  "format_ids": [
+    { "agent_url": "https://creative.adcontextprotocol.org", "id": "meta_reels" }
+  ],
+  // ... pricing, targeting, etc.
+}
+```
+
+### v2 — inline format declarations on the product
+
+```json test=false
+{
+  "product_id": "meta_reels_us",
+  "name": "Meta Reels — United States",
+  "format_options": [
+    {
+      "format_kind": "video_hosted",
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_range": [3000, 90000],
+        "min_width": 1080,
+        "min_height": 1920,
+        "video_codecs": ["h264"],
+        "containers": ["mp4"],
+        "headline_max_chars": 25,
+        "primary_text_max_chars": 72,
+        "cta_values": ["LEARN_MORE", "SHOP_NOW", "DOWNLOAD", "SIGN_UP"],
+        "composition_model": "deterministic",
+        "platform_extensions": [
+          { "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel", "digest": "sha256:..." }
+        ]
+      }
+    }
+  ],
+  // ... pricing, targeting, etc.
+}
+```
+
+`format_options` is an array. The 90% case is one element — one canonical narrowed for the product. Multi-element arrays declare that the product accepts any of the listed format options, picked by the buyer at `sync_creatives` time. Common multi-element use cases: a placement that accepts EITHER a third-party-hosted creative (e.g., Flashtalking-served `html5`) OR an internal `display_tag`; a video product that accepts a hosted upload (`video_hosted`) OR a tag (`video_vast`). Each entry is a discriminated union: `format_kind` names the canonical format; `params` carries that canonical's parameter schema. SDKs codegen clean tagged unions in TypeScript and Pydantic.
+
+**Dual emission during the migration window**: Products MAY carry `format_ids`, `format_options`, or BOTH; at least one is required (the schema enforces this via an `anyOf`, not `oneOf`). The recommended seller pattern is to author once and let the SDK project to both wire shapes via the [v1↔v2 canonical mapping registry](https://adcontextprotocol.org/schemas/v3/registries/v1-canonical-mapping.json), so every buyer reads what it knows. When both shapes are present on a product, the two MUST refer to the same underlying format declaration — the `format_options[i]` must narrow the canonical that `format_ids[i]` resolves to via the registry. SDKs that derive both shapes from one source guarantee this invariant; SDKs that hand-author both MUST treat divergence as a build error and refuse to emit. Buyers prefer `format_options` when both are present; treat `format_ids` as fallback for v1-only buyers. Sellers whose v1 named formats have no clean v2 projection ship `format_ids` only for those products until they add an explicit `canonical` declaration on the v1 format (see "v1 → v2 canonical mapping" below) — the SDK MUST NOT emit `format_options` for non-projectable formats.
+
+For 12 fully-validated reference Product fixtures spanning the 12 canonical formats (native_in_feed fixture follows in a subsequent PR) — Meta Reels (`video_hosted` vertical), IAB MREC (`image` 300×250), NYTimes HTML5 (`html5`), GAM 3P display tag (`display_tag`), Meta Carousel (`image_carousel`), YouTube VAST pre-roll (`video_vast`), podcast 30s host-read (`audio_hosted`), Triton DAAST audio (`audio_daast`), Amazon Sponsored Products (`sponsored_placement`), Google PMax (`responsive_creative`), ChatGPT brand mention (`agent_placement`), Veo 15s generative video (`video_hosted` with `synthesis_nondeterministic` + `provenance_required`) — plus 1 `get_products` response fixture exercising bundled extensions, see `static/examples/products/canonical/` and `static/examples/get_products_responses/canonical/`. The Veo fixture exercises `synthesis_nondeterministic: true` and `provenance_required: true`. Each fixture passes `npm run test:canonical-fixtures`.
+
+## v1 → v2 canonical mapping
+
+The slot-level `asset_group_id` bridge below tells SDKs which v2 canonical *slot* a v1 slot corresponds to. The format-level mapping — which v2 *canonical format* a v1 named format projects to — is solved by two complementary mechanisms:
+
+### The canonical mapping registry
+
+[`/schemas/registries/v1-canonical-mapping.json`](https://adcontextprotocol.org/schemas/v3/registries/v1-canonical-mapping.json) is the authoritative AAO-published registry. SDKs consume it to project v1 formats to v2 canonicals during dual-emission and v1↔v2 translation. Two match modes per entry:
+
+- **`format_id_glob`** — exact / glob match against v1 `format_id.id`. Covers IAB-conventional sizes (`iab/mrec_300x250` → `image` 300×250), named platform formats, common publisher conventions.
+- **`structural`** — match against the format's slot shape, asset types, and version constraints. Catches custom v1 formats that are structurally a standard format under a different name (a seller's `acme_homepage_300x250` is structurally an IAB MREC).
+
+Initial registry covers ~15 unambiguous entries (IAB display sizes, VAST 4.x, DAAST 1.x). Subsequent PRs expand coverage as adopter feedback surfaces patterns. Governance follows the same rules as `asset-group-vocabulary.json`: PR with rationale + ≥1 reference adopter + AAO maintainer review; entries are additive and digest-pinned.
+
+### `canonical` field on v1 format declarations (custom / non-registered formats)
+
+For custom seller formats not covered by the registry, the seller declares the mapping inline at the v1 format-declaration level:
+
+```json test=false
+{
+  "format_id": "acme/sponsored_recipe_card",
+  "name": "Sponsored Recipe Card",
+  "canonical": { "kind": "sponsored_placement" },
+  "canonical_parameters": {
+    "format_kind": "sponsored_placement",
+    "params": {
+      "supported_catalog_types": ["product"],
+      "supported_id_types": ["sku"],
+      "fanout_mode": "per_item",
+      "item_production_model": "buyer_uploaded"
+    }
+  },
+  "assets": [
+    { "asset_id": "headline", "asset_type": "text", "asset_group_id": "headline", "required": true },
+    { "asset_id": "recipe_image", "asset_type": "image", "asset_group_id": "image_main", "required": true }
+  ]
+}
+```
+
+The `canonical` field names the v2 canonical; `canonical_parameters` (optional) carries a full ProductFormatDeclaration the SDK projects this v1 format into. Combined with slot-level `asset_group_id` declarations on each `assets[]` entry, the v1 format becomes fully self-describing for v1↔v2 translation. Seller does this once per custom format, not per buyer or per product.
+
+For the `format_kind: "custom"` case (a custom seller format that itself doesn't fit any v2 canonical), the `canonical_parameters` carries the same `format_kind: "custom"` + `format_shape` + `format_schema` triple as a normal v2 declaration would.
+
+### Normative SDK projection rules
+
+Resolution order when an SDK projects a v1 format to its v2 canonical (or back):
+
+1. If the v1 format declaration carries `canonical`, use it (seller-declared, highest priority). When `canonical_parameters` is also present, use that as the projected ProductFormatDeclaration verbatim.
+2. Else, look up `format_id` in `/schemas/registries/v1-canonical-mapping.json`'s `format_id_glob` entries.
+3. Else, attempt structural match against the registry's `structural` entries.
+4. Else, **fail closed**: SDK MUST NOT emit `format_options` for products carrying this format. Surface a validation warning suggesting the seller add an explicit `canonical` field or file a registry entry. Buyers see `format_ids` only for these products.
+
+Reverse direction (v2 → v1 demotion for v1-only buyers reading a v2 seller) is the inverse projection: same registry, same algorithm, run backward. SDKs ship a single mapping engine that handles both directions.
+
+This is what makes "publish both wire shapes during migration" tractable and consistent across SDK implementations — every SDK projects through the same registry so dual-emitted products from any seller resolve identically across any buyer.
+
+## Slot name mapping (v1 → canonical)
+
+If a v1 format slot uses an author-invented name that the canonical vocabulary covers, the format declaration carries an optional `asset_group_id` field on the slot pointing at the canonical entry. Same as the existing `asset_role` field, but referencing the [canonical vocabulary](https://adcontextprotocol.org/schemas/v3/core/asset-group-vocabulary.json) rather than free text.
+
+```json test=false
+// v1 format with author-invented slot name
+{
+  "asset_id": "click_url",
+  "asset_type": "url",
+  "item_type": "individual",
+  "required": true
+}
+
+// Same v1 format with canonical pointer (additive — backwards-compatible)
+{
+  "asset_id": "click_url",
+  "asset_type": "url",
+  "asset_group_id": "landing_page_url",
+  "item_type": "individual",
+  "required": true
+}
+```
+
+The vocabulary registry's `aliases` field captures common v1 alias names per canonical entry (e.g., `landing_page_url` aliases include `click_url`, `link`, `final_url`, `link_url`, `click_through_url`, `landing_url`). Six different names for the same field collapse to one canonical.
+
+Common alias mappings (from the audit-grounded set in `asset-group-vocabulary.json`):
+
+| Canonical | Common v1 aliases |
+|---|---|
+| `headlines` | `headline`, `title`, `tagline`, `headline_text` |
+| `descriptions` | `description`, `body`, `body_text`, `text`, `content` |
+| `images_landscape` | `image`, `hero_image`, `landscape_image`, `banner_image` |
+| `images_vertical` | `vertical_image`, `story_image`, `portrait_image` |
+| `images_square` | `square_image`, `feed_image` |
+| `logo` | `brand_logo`, `logo_image` |
+| `video` | `video_file`, `hero_video`, `video_asset`, `video_main` |
+| `audio` | `audio_file`, `hero_audio`, `audio_asset`, `audio_main` |
+| `landing_page_url` | `click_url`, `link`, `final_url`, `link_url`, `click_through_url`, `landing_url` |
+
+## Discovery surface migration
+
+`list_creative_formats` is uniformly deprecated. Replacements:
+
+| Role | v1 path | v2 path |
+|---|---|---|
+| Sales agent | `list_creative_formats` returns the seller's accepted formats | `get_products` — each product carries its `format` declaration inline. Optionally also `creative.supported_formats` on `get_adcp_capabilities` for a flat summary. |
+| Creative agent (no inventory) | `list_creative_formats` overloaded as "what I can produce" | `creative.supported_formats` on `get_adcp_capabilities`. Each entry uses the same `ProductFormatDeclaration` shape as products' inline `format`. |
+
+Sellers SHOULD provide a server-side flatten wrapper that derives the v1 `list_creative_formats` shape from v2 product format declarations through 4.0, so existing dashboards and tooling keep working. The wrapper iterates over `get_products`, reads each product's `format` declaration, and emits a v1-compatible format file plus a `format_ids` reference.
+
+## Generative formats — `*_generated_*` files dissolve
+
+The agentic-adapters audit found ~30 `*_generated_*` format files (e.g., `meta_generated_reels`, `tiktok_generated_video_9x16`) that mirror their non-generated counterparts but accept a `creative_brief` instead of an asset upload. In v2 these collapse:
+
+- The format declaration's `slots` array enumerates everything the buyer ships in the manifest's `assets` map — each entry is a canonical `asset_group_id` paired with an `asset_type`. Some slots are rendered verbatim (image / video / audio); some are consumed for production (text script → host-read audio; brief → synthesized image; video_brief → generated video). The seller dispatches per slot.
+- Whether the seller's internal production is generative AI, host recording, transcoding, or asset rendering is **invisible to the buyer**
+- A single canonical format (e.g., `audio_hosted`) handles both buyer-uploaded audio and agent-produced audio; the format's `asset_source` and `buyer_asset_acceptance` parameters describe which flows are accepted
+
+Side-by-side for an audio format:
+
+```json test=false
+// v1: separate generated format file
+{
+  "format_id": { "agent_url": "...", "id": "audiostack_audio_30s_generated" },
+  "name": "AudioStack 30s Audio (Generated)",
+  "assets": [
+    {
+      "asset_id": "creative_brief",
+      "asset_type": "brief",
+      "required": true
+    },
+    {
+      "asset_id": "audio_output",
+      "asset_type": "audio",
+      "required": false
+    }
+  ]
+}
+
+// v2: same canonical (audio_hosted), buyer-shipped assets declared as slots
+{
+  "format_kind": "audio_hosted",
+  "params": {
+    "duration_ms_exact": 30000,
+    "audio_codecs": ["mp3"],
+    "loudness_lufs": -16,
+    "asset_source": "agent_synthesized",
+    "buyer_asset_acceptance": "rejected",
+    "slots": [
+      { "asset_group_id": "creative_brief", "required": true, "asset_type": "brief", "max_chars": 1000 },
+      { "asset_group_id": "voice_id", "required": false, "asset_type": "text" }
+    ],
+    "production_window_business_days": 0
+  }
+}
+```
+
+Note the v2 manifest has no separate `inputs` map — the buyer ships the brief and voice_id as `text`/`brief` assets in the `assets` map under those slot names. The seller dispatches per the format's slot declaration: brief → consume for synthesis; rendered audio is what comes out the other side.
+
+## Brand identity — slots disappear
+
+v1 formats sometimes redeclared `brand_logo`, `brand_colors`, `brand_voice`, `brand_tagline` as explicit slots. v2 formats don't. When the manifest carries a [`BrandRef`](https://adcontextprotocol.org/schemas/v3/core/brand-ref.json) (`brand: { domain: "acme.com" }`, optionally with `brand_id` for house-of-brands), the seller fetches `brand.json` for context automatically.
+
+For the case where `brand.json` is missing or stale, the BrandRef itself carries an inline `brand_kit_override` (same inline-override pattern BrandRef already uses for `industries` and `data_subject_contestation`):
+
+```json test=false
+{
+  "format_id": { "agent_url": "...", "id": "..." },
+  "assets": { ... },
+  "brand": {
+    "domain": "acme.example",
+    "brand_kit_override": {
+      "logo": { "asset_type": "image", "url": "https://cdn.acme.example/logo-2026.png", "width": 200, "height": 100 },
+      "colors": { "primary": "#0066CC", "accent": "#FF6600" },
+      "tagline": "Spring savings, all season"
+    }
+  }
+}
+```
+
+Override fields take precedence over `brand.json` for the call carrying this BrandRef.
+
+## Tools — what's new vs unchanged
+
+| Tool | v1 | v2 |
+|---|---|---|
+| `get_products` | Returns products with `format_ids` | Returns products with either `format_ids` (v1 path) or `format` (v2 inline) |
+| `sync_creatives` | Submit creative manifest | Unchanged. Sales agents accept manifests with `assets` keyed by slot name per the format's `slots` declaration. |
+| `preview_creative` | Submit manifest, get preview | Same surface; preview shows output regardless of whether the slots ship rendered creative (image/video/audio) or production content (script/brief/video_brief). The single-render hoist in #3268 lands alongside v2. |
+| `validate_input` | (didn't exist) | New buyer dry-run primitive. Validates a manifest against canonical formats and/or specific products without committing to a render. Cheap; `predicted` field carries pre-flight estimates. |
+| `build_creative` | Generative tool on creative agents | Same role; creative-agent surface only. Sales agents do **not** expose `build_creative`. Creative agents may **also** expose `sync_creatives` for ad-server use cases. |
+| `list_creative_formats` | Both sales and creative agents | Deprecated. Sales agents migrate to `get_products`; creative agents to `creative.supported_formats`. v1 tool stays functional through 4.x. |
+
+## Adopter migration paths
+
+### Sales agents (DSPs, SSPs, retail media networks, walled gardens)
+
+1. **Inventory**: enumerate your existing v1 named formats. Confirm each maps to one of the 12 v2 canonicals OR to a custom shape (see "Shipping a custom format" below). Composed/coordinated/sponsorship shapes (multi-placement takeover, roadblock, branded content, cross-screen sponsorship, sponsorship lockup, newsletter, AR lens, playable, live event sponsorship) ship as `format_kind: "custom"` with a `format_shape` registry classifier and a `format_schema` URI+digest reference.
+2. **Translate**: for each named format, write a v2 `ProductFormatDeclaration` narrowing the canonical with your platform's parameters. For custom shapes, author a JSON Schema describing your format's `params` and `slots`, host it at a stable URI on your subdomain (or via the AAO mirror for walled-garden sellers), and reference it from `format_schema`.
+3. **Be honest about runtime readiness**: set `experimental: true` on each declaration whose runtime path isn't fully wired yet. Same flag whether the concern is "spec is still settling" (canonical-level) or "my runtime is mid-migration" (declaration-level). Buyers SHOULD filter `experimental: true` from default views; they SHOULD prefer the v1 fallback (via the declaration's `v1_format_ref` or the parent product's `format_ids`) until you drop the flag. Drop the flag when the runtime catches up.
+4. **Test**: validate translated declarations against `/schemas/core/product.json` (use the `npm run test:canonical-fixtures` pattern).
+5. **Publish dual**: keep your v1 named formats and `list_creative_formats` working through 4.x. Add the v2 `format_options` field on products that have it.
+6. **Flatten wrapper**: implement a server-side wrapper that derives the v1 `list_creative_formats` shape from v2 product declarations. Lets v1-era dashboards and tooling keep working.
+7. **Deprecate timing**: at 5.0, remove v1 `format_ids` references on your products. Until then, both paths coexist.
+
+#### Server-side implementation considerations
+
+Three concrete hooks v2 introduces that existing seller implementations don't have today:
+
+- **`sync_creatives` provenance verification when `provenance_required: true`.** When a v2 product's format declaration carries `provenance_required: true` (and the buyer's manifest contains synthesized assets — typically video/image from generative platforms), `sync_creatives` MUST verify a C2PA-compatible provenance manifest is attached and reject unsigned synthesized assets. This is a natural extension of existing AI-provenance tracking on Creative (EU AI Act Article 50 work) — the new piece is a validation hook that gates submission. Sellers without existing provenance plumbing only need this once they ship a v2 product with the flag set; until then it's no-op.
+- **`get_products` response gathers extension definitions.** When products carry v2 `format.params.platform_extensions` references, the response SHOULD include the referenced extension definitions in the `extensions` map keyed by `<uri>@sha256:<digest>`. Implementations gather extensions referenced by any product in the response, dedupe by digest, and emit. Buyers cache by URI@digest; subsequent responses MAY omit definitions the buyer already has cached. Trivial when no products use v2 declarations; only kicks in when tenants opt in.
+- **`production_window_business_days` on host-read / agent-produced products.** Today most server implementations don't model production turnaround on Products — the field is a v2 addition. Only matters once a tenant ships a v2 host-read or generative-video product (audio_hosted with `asset_source: 'publisher_host_recorded'`, or any product with `synthesis_nondeterministic: true`). Today many of these flows route through hand-trafficked sponsorships and don't surface turnaround over the protocol; v2 makes it declarable.
+
+#### Shipping a custom format
+
+Sellers with creative structures that don't fit the 12 canonicals (multi-placement takeover, roadblock, branded content, cross-screen sponsorship, sponsorship lockup, newsletter sponsorship, AR lens, playable, live event sponsorship) ship via `format_kind: "custom"`. Three pieces:
+
+1. **Pick a `format_shape`** from the [vocabulary registry](https://adcontextprotocol.org/schemas/v3/core/format-shape-vocabulary.json). If your shape isn't there, file a vocabulary PR — adding entries is governance-light, doesn't require a major version bump, and helps the working group track adoption velocity per shape.
+2. **Author a JSON Schema** describing your format's `params` and `slots`. The schema's job is to give buyer agents enough structure to validate manifests and reason about what assets you accept, how you track, what the impression contract is. Treat it like authoring a v1 named format file — same level of rigor, just hosted at your URI rather than under AdCP's roof. Industry-shared schemas (e.g., a shared `multi_placement_takeover_v1` schema several publishers converge on) are encouraged and accelerate canonical promotion.
+3. **Host the schema at a stable URI** with `Cache-Control: public, max-age=31536000, immutable` and a digest. Open-ecosystem publishers host on their own subdomain (`https://yourpub.example/schemas/formats/your_shape_v1`); walled-garden sellers route through the AAO mirror at `https://creative.adcontextprotocol.org/translated/<vendor>/<shape>` (AAO accepts translation submissions; same hosting / immutability contract). Reference the schema from `format_schema: { uri, digest }` on your `ProductFormatDeclaration`.
+
+Buyer agents fetch the schema by `uri@digest`, cache it (immutable), and validate manifests structurally. **No human-in-the-loop is required for buyer agents to interpret your format** — that's the load-bearing claim and the reason custom + format_schema isn't `ext`. Ext remains for genuinely experimental shapes that don't even fit a `format_shape` entry yet, but that's the rare case.
+
+When 2+ adopters ship the same `format_shape` with substantively similar `format_schema` content for 90+ days, the working group promotes the shape to a first-class canonical (creates `/schemas/formats/canonical/<name>.json`, adds the value to `canonical-format-kind.json`, retires the registry entry). Adopters migrate from `format_kind: "custom"` to `format_kind: "<canonical>"` at that point. The promotion queue is tracked at [adcp#3666](https://github.com/adcontextprotocol/adcp/issues/3666).
+
+### Creative agents (Flashtalking, AudioStack, generative platforms, AI rendering services)
+
+The spec has historically read sales-agent-first. v2 reshapes the creative-agent path enough to warrant its own walkthrough — both for ad-server-shaped creative agents (Flashtalking, Innovid, Sizmek-class) and transformation-shaped creative agents (AudioStack, Pencil, AdCreative.ai-class).
+
+#### What changes for a creative agent in v2
+
+| Concern | v1 | v2 |
+|---|---|---|
+| Format catalog publishing | `list_creative_formats` returned your producible catalog; sales agents could reference it via `creative_agents[]` recursive-discovery hint on their own `list_creative_formats` | `creative.supported_formats` on `get_adcp_capabilities` (each entry is a `ProductFormatDeclaration` — same shape as a sales agent's product `format_options[i]`). v1 `list_creative_formats` stays functional through 4.x. |
+| Format authoring | You authored named formats keyed under `your-domain.example` and published them | You declare which AdCP-defined canonical formats you can produce (`format_kind` discriminator) with your platform-specific narrowing (`params`). No more publishing free-text named formats. |
+| Discovery | Sales agents pointed buyers at you via `creative_agents[]` (recursive query); buyers fetched your `list_creative_formats` to learn what you produce | Buyers reach you directly — through brand-side relationships, AAO registry, direct knowledge. Sales agents in v2 do NOT carry a list of "approved creative agents." Each side is independent. |
+| `build_creative` contract | Buyer shipped a manifest with `format_id` + `assets` + `inputs` (separate "production inputs" map) | Buyer ships the same envelope, but `inputs` is collapsed into `assets` — everything goes through one `assets` map keyed by canonical `asset_group_id`. The format's `slots` declaration tells you which assets to expect, each typed by `asset_type`. The seller (you) dispatches per slot — render verbatim for `image` / `video` / `audio` slots; consume for production for `text` / `brief` / `object` slots (e.g., `script` text → host-recorded audio; `creative_brief` brief → generated image). |
+| Production-source declaration | Implicit (the named format's name implied the model — `*_generated_*` for AI-produced) | Explicit per-canonical: `asset_source` / `asset_source` / `asset_source` enums declare who renders and when (`buyer_uploaded` / `publisher_host_recorded` / `seller_pre_rendered_from_brief` / `seller_human_designed` / `agent_synthesized`). Plus `synthesis_nondeterministic: true` for Veo/Sora-class flows that need post-synthesis QA-loop semantics. |
+| Tracking integration | Your platform's pixel IDs, viewability vendors, OM-SDK partners lived in your named format's `tracking_events` field — sellers and buyers parsed your free-text declarations | Declare via `platform_extensions: [{uri, digest}]` on each `supported_formats[].format`. Each extension is a URI you host (or the AAO mirror translates) describing the schema for your platform's tracking surface (pixel IDs, conversion event taxonomies). The extension's `extends: "tracking"` metadata lets buyers filter tracking-related entries without a separate `tracking_extensions` array. Sellers and buyers cache by `uri@digest`; SDK codegen produces typed extension handlers. |
+| Hosting of produced bytes | Your CDN, your call | Your CDN, your call. v2 disaggregation is conceptual (the spec separates production from serving from tracking) — operationally, produced asset URLs in the manifest you return from `build_creative` continue to point at your CDN, your tracking JS continues to instrument, your platform extensions document the integration. |
+
+#### Concrete example: Flashtalking-shaped creative agent
+
+A creative agent that produces image / VAST / html5 creatives across multiple sizes and surfaces. Pre-v2, it published 30+ named formats (one per size × surface combination). v2 collapses to a smaller `supported_formats` set:
+
+```json test=false
+// GET https://flashtalking.example/.well-known/agent.json
+// → get_adcp_capabilities response (excerpt)
+{
+  "creative": {
+    "supports_generation": true,
+    "supports_transformation": true,
+    "has_creative_library": true,
+    "supported_formats": [
+      {
+        "capability_id": "flashtalking_image_iab_standard",
+        "format": {
+          "format_kind": "image",
+          "params": {
+            "image_formats": ["jpg", "png", "gif"],
+            "max_file_size_kb": 200,
+            "ssl_required": true,
+            "asset_source": "buyer_uploaded",
+            "platform_extensions": [
+              { "uri": "https://flashtalking.example/extensions/flashtalking_pixel_v2", "digest": "sha256:..." }
+            ]
+          }
+        }
+      },
+      {
+        "capability_id": "flashtalking_video_vast_42",
+        "format": {
+          "format_kind": "video_vast",
+          "params": {
+            "vast_version": "4.2",
+            "duration_ms_range": [6000, 60000],
+            "linear_required": true,
+            "ssl_required": true,
+            "platform_extensions": [
+              { "uri": "https://flashtalking.example/extensions/flashtalking_vpaid_2_0", "digest": "sha256:..." }
+            ]
+          }
+        }
+      },
+      {
+        "capability_id": "flashtalking_html5_iab_standard",
+        "format": {
+          "format_kind": "html5",
+          "params": {
+            "max_initial_load_kb": 200,
+            "om_sdk_required": true,
+            "backup_image_required": true,
+            "ssl_required": true
+          }
+        }
+      }
+    ]
+  }
+}
+```
+
+What disappears: 30+ named-format files, each with its own `tracking_events` array, each with its own slot vocabulary. What replaces them: 3 canonical declarations narrowed by params + platform_extensions for Flashtalking-specific tracking. SDK codegen on the buyer side produces a typed handler per `format_kind` rather than a typed handler per Flashtalking-named-format — a 10× reduction in surface area for buyers integrating Flashtalking.
+
+The buyer flow is unchanged from a Flashtalking perspective: `build_creative` still receives a brief / assets / brand reference; you produce a manifest with rendered asset URLs on Flashtalking's CDN; the buyer submits that manifest to whatever sales agent they're shipping to. The sales agent validates against canonical `image` / `video_vast` / `html5` — NOT against your Flashtalking narrowing. Your platform_extensions remain attached to the manifest so the sales agent honors Flashtalking pixel IDs and viewability vendors at serve time.
+
+#### Concrete example: AudioStack-shaped transformation agent
+
+A transformation agent that takes a buyer's brief or script and produces a rendered audio file. Pre-v2, AudioStack published `audiostack_audio_30s_generated` and similar. v2 collapses to a per-canonical declaration with explicit production-source semantics:
+
+```json test=false
+// GET https://audiostack.example/.well-known/agent.json
+{
+  "creative": {
+    "supports_generation": true,
+    "supports_transformation": true,
+    "supported_formats": [
+      {
+        "capability_id": "audiostack_audio_brief_to_30s",
+        "format": {
+          "format_kind": "audio_hosted",
+          "params": {
+            "duration_ms_exact": 30000,
+            "audio_codecs": ["mp3", "aac"],
+            "audio_sample_rates": [44100, 48000],
+            "audio_channels": ["stereo"],
+            "loudness_lufs": -16,
+            "asset_source": "seller_pre_rendered_from_brief",
+            "buyer_asset_acceptance": "rejected",
+            "production_window_business_days": 1,
+            "slots": [
+              { "asset_group_id": "creative_brief", "asset_type": "brief", "required": true, "max_chars": 500 },
+              { "asset_group_id": "voice_id", "asset_type": "text", "required": false },
+              { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+            ]
+          }
+        }
+      },
+      {
+        "capability_id": "audiostack_audio_script_to_30s",
+        "format": {
+          "format_kind": "audio_hosted",
+          "params": {
+            "duration_ms_exact": 30000,
+            "audio_codecs": ["mp3"],
+            "asset_source": "agent_synthesized",
+            "buyer_asset_acceptance": "rejected",
+            "synthesis_nondeterministic": false,
+            "production_window_business_days": 0,
+            "slots": [
+              { "asset_group_id": "script", "asset_type": "text", "required": true, "max_chars": 800 },
+              { "asset_group_id": "voice_id", "asset_type": "text", "required": true }
+            ]
+          }
+        }
+      }
+    ]
+  }
+}
+```
+
+Two distinct capabilities — brief-to-audio (creative direction → produced ad) and script-to-audio (deterministic TTS from verbatim script) — declared as two `supported_formats` entries sharing `format_kind: audio_hosted` but with different `asset_source` values. `capability_id` disambiguates which capability the buyer is invoking when they call `build_creative`.
+
+#### Server-side hooks for creative agents
+
+Three implementation considerations specific to creative agents in v2:
+
+- **`creative.supported_formats` is your public contract.** Buyers and sales agents read it to know what you produce. Keep `capability_id` values stable across releases — buyers reference them in their `build_creative` calls.
+- **`synthesis_nondeterministic: true` implies a QA-loop obligation.** When you declare it, you commit to: validating each synthesis attempt against the format's parameter constraints; reseeding up to N times to produce in-spec output; returning `task_failed` with `synthesis_failed` reason if the loop exhausts. There is no protocol state for orphaned out-of-spec artifacts — the buyer never sees a partial result.
+- **`provenance_required: true` requires C2PA attestation.** When a sales agent's product carries `provenance_required: true` and the buyer is shipping your produced asset, the manifest you return MUST include a C2PA-compatible provenance manifest attributing synthesis to your agent (not the buyer, not the seller). EU AI Act Article 50 alignment.
+
+#### Migration timing for creative agents
+
+| Item | Timing |
+|---|---|
+| Continue to expose `list_creative_formats` (v1) | Through 4.x. Sales agents and buyers may still call it. |
+| Add `creative.supported_formats` to `get_adcp_capabilities` | Anytime in 3.1+. Additive — doesn't break v1 callers. |
+| Stop publishing new v1 named formats | When 80% of your buyers are reading `supported_formats` (track via your own analytics — buyers calling `get_adcp_capabilities` vs `list_creative_formats`). |
+| Drop `list_creative_formats` | Coordinated with the v1 deprecation calendar (2027-Q4 floor / 2029-Q1 ceiling) — same window as sales agents dropping `format_ids`. |
+
+### Buyers / DSPs
+
+1. Update your client to read either `format_ids` (v1) or `format` (v2 inline) on products.
+2. Use `validate_input` for cheap dry-run validation before committing to renders.
+3. Use the canonical [`asset_group_id` vocabulary](https://adcontextprotocol.org/schemas/v3/core/asset-group-vocabulary.json) when constructing manifests; the registry's `aliases` field maps v1-era slot names to canonical equivalents.
+4. Submit creative via `sync_creatives` as before. For products whose slots accept production content (host-read podcasts ship a `script` text asset; generative video ships a `creative_brief` and `video_brief`), either pre-produce via a creative agent's `build_creative` to get back a manifest with rendered assets OR submit the production-content assets directly and let the seller produce internally — both flows are valid.
+
+### Publisher direct (GAM/prebid path)
+
+1. The `zip` asset type (Phase 1) handles HTML5 banner bundles cleanly. URL-delivered HTML/JS routes through `url-asset.json` with appropriate `url_type`.
+2. Tag-based delivery (VAST, third-party display tags) maps to the `display_tag`, `video_vast`, and `audio_daast` canonical formats.
+3. Native canonical format is deferred to 3.2 after the TemplateCreative + OpenRTB Native 1.2 audit; until then, native formats stay on the v1 path.
+
+## Realistic timeline by adopter type
+
+| Adopter | Cost | Realistic timeline |
+|---|---|---|
+| DSP buyer agents (TTD-shaped) | Low | 3.1-3.2 |
+| SSP/sales agents (Magnite, PubMatic, retail media) | Medium-high | 3.3-4.0 |
+| Walled gardens (Meta, Google, Amazon, TikTok, Snap, Pinterest) | High, low motivation | 4.0-5.0 if at all (gated on AAO providing a translator from existing format docs) |
+| Creative agents (AudioStack-shaped) | Low, high motivation | 3.1-3.2 |
+| Publisher direct (GAM/prebid path) | Medium | Blocked on native canonical pre-audit |
+
+### When does v1 `format_ids` get removed?
+
+The `oneOf(format_ids, format_options)` shape on `Product` persists through 4.x — every validator, codegen, and adopter has to handle both shapes. The 5.0 cut is **adoption-driven, with calendar floor and ceiling**:
+
+- **Floor (minimum end-of-life)**: v1 `format_ids` is supported through at least **2027-Q4** regardless of adoption signal. Adopters whose org reality (legacy ad-server integrations, walled-garden translation gaps, slow procurement cycles) prevents immediate migration get an unconditional 18-month runway from 3.1 GA.
+- **Ceiling (maximum end-of-life)**: v1 `format_ids` is removed no later than **2029-Q1** regardless of adoption signal. Caps the long-tail liability for SDK authors and validator maintainers; matches the v2-sunset-policy pattern from 3.0.
+- **Adoption trigger (within the floor / ceiling window)**: AAO computes the ratio of registered sales agents declaring `format_options` (vs `format_ids`) from cached `get_products` capabilities responses. The trigger is denominator = sales agents declaring `creative` in `supported_protocols`; numerator = those whose latest `get_products` response carries `format_options` on every product. When the ratio crosses **80% and stays there for 30 consecutive days** within the floor/ceiling window, the 5.0 cut sequence opens (deprecation warnings escalate; the next major drops `format_ids`). Until that signal trips, both shapes remain valid.
+
+The trigger metric, denominator, refresh cadence, and certification path are published at `https://adcontextprotocol.org/registry/format-options-adoption.json` (concrete shape and refresh cadence to be committed in a follow-up issue before 3.1 GA). Adopters who want to influence the timing should migrate early and watch the public ratio. Walled gardens that don't migrate are absorbed by the ceiling.
+
+### `creative_id` stability across v1 ↔ v2
+
+A creative registered against v1 `format_id` retains the same `creative_id` when later viewed via the v2 flatten path. `sync_creatives` request and response shapes are unchanged; the manifest envelope is unchanged. Migration is read-side: existing creatives keep working and resolve identically through both paths. SDK authors building flatten wrappers MUST honor this invariant.
+
+## `product_card` and `product_card_detailed` are typed inline
+
+The `product_card` and `product_card_detailed` fields on the `Product` object are typed inline structures in v2 — no `format_id` indirection, no manifest. They describe the **UI rendering of the product itself** (what catalog browsers, dashboards, and admin interfaces display so humans and agents can see what a product is). Distinct from `format` (which describes the ad creative the product accepts).
+
+```json test=false
+"product_card": {
+  "image": { "asset_type": "image", "url": "https://...", "width": 300, "height": 400 },
+  "title": "Meta Reels — United States",
+  "description": "9:16 vertical short-form video on Meta Reels.",
+  "price_label": "From $5.50 CPM",
+  "cta_label": "View details"
+}
+
+"product_card_detailed": {
+  "hero_image": { "asset_type": "image", "url": "...", "width": 1200, "height": 600 },
+  "carousel_images": [ { "asset_type": "image", "url": "...", ... }, ... ],
+  "title": "Meta Reels — United States",
+  "description": "Full markdown-friendly product description...",
+  "specifications": [
+    { "label": "Aspect ratio", "value": "9:16" },
+    { "label": "Duration", "value": "3-90s" }
+  ],
+  "price_label": "From $5.50 CPM",
+  "cta_label": "Get proposal"
+}
+```
+
+Migration from v1 (where `product_card` was `{ format_id, manifest }` referencing a `product_card_standard` format file): drop the format reference; populate the typed fields directly. The image, title, and description flatten out of what was previously a manifest. v2-only adopters who don't render product cards can ignore both fields entirely.
+
+## What v2 gives you that OpenRTB doesn't
+
+Adopters with existing OpenRTB Native / Display / Audio pipelines reasonably ask "why migrate to v2 when I already have a working creative-spec model?" The differential value:
+
+- **Buyer validates against the canonical, not the seller's narrowing.** OpenRTB has no canonical layer. Each SSP authors its own native asset spec (Native 1.2 left placement-specific assets to "see the impl"); each video player authors its own VAST extensions; each retail-media network publishes its own catalog field shape. Buyers must discover and validate against per-seller specs at runtime. v2's canonical-as-contract decouples buyer validation from per-seller schema discovery — the buyer ships a manifest that satisfies canonical `image` and knows it's structurally valid against any seller speaking that canonical, BEFORE knowing which seller wins the auction.
+- **Discovery is operational, not implicit.** OpenRTB Display 1.x and Native 1.2 expect adopters to read the spec, write per-version handlers, and pre-bake support for what each seller might require. v2 carries the format declaration inline on the product (`format_options[i]` on `get_products`) and on the creative agent (`creative.supported_formats` on `get_adcp_capabilities`). Buyers fetch what's accepted at runtime; SDK codegen produces typed handlers for the canonicals; new sellers don't require buyer-side code changes.
+- **Production source is first-class.** OpenRTB has no notion of "buyer ships a brief; seller renders." The closest expression is OpenRTB Native's `nobid_reason` after submission. v2 makes production source a declared parameter (`*_source` enums), so generative DSPs and host-read products are visible at discovery time, not only after rejection.
+- **Tracking model is canonical-defined.** OpenRTB tracking (impression NURL, click NURL, third-party trackers) is consistent for VAST but fragmented for native and display. v2 bakes the tracking model into each canonical (impression pixel for image, MRAID + OM-SDK for html5, VAST events for video_vast, per-card pixels for image_carousel) — buyers know what tracking shape applies from the canonical alone.
+
+v2 doesn't replace OpenRTB at the auction layer (where OpenRTB Display, Video, Audio specs continue to drive the bid request / response shape). v2 is the creative-payload layer above the auction, and it adds what OpenRTB intentionally left implementation-specific.
+
+## Validating your migration
+
+Run the fixture validation against your translated products:
+
+```bash test=false
+npm run test:canonical-fixtures
+```
+
+The reference fixtures at `static/examples/products/canonical/` are validated against `/schemas/core/product.json`. Adopters can drop their own translated products into a sibling directory and reuse the same validator pattern.
+
+## Related
+
+- [Canonical Formats overview](/docs/creative/canonical-formats)
+- [RFC #3305](https://github.com/adcontextprotocol/adcp/issues/3305) — architectural decisions and rationale
+- [Asset group vocabulary](https://adcontextprotocol.org/schemas/v3/core/asset-group-vocabulary.json)
+- [BrandRef schema](https://adcontextprotocol.org/schemas/v3/core/brand-ref.json)
+- [Universal macros](/docs/creative/universal-macros) — substitution patterns referenced from canonical tracking
diff --git a/docs/creative/canonical-formats.mdx b/docs/creative/canonical-formats.mdx
new file mode 100644
index 0000000000..3f1533361c
--- /dev/null
+++ b/docs/creative/canonical-formats.mdx
@@ -0,0 +1,1254 @@
+---
+title: Canonical Formats (preview)
+description: "Canonical formats live on AdCP; sellers' products narrow them inline. Phase 1 + Phase 2 preview against RFC #3305."
+"og:title": "AdCP — Canonical Formats"
+testable: true
+---
+
+# Canonical Formats (preview)
+
+> **TL;DR for adopters reading cold:**
+> - **7 of 12 canonical formats ship `stable` at 3.1 GA** (`image`, `display_tag`, `video_hosted`, `video_vast`, `audio_hosted`, `audio_daast`, `native_in_feed` — all re-encodings of IAB / VAST / DAAST / IAB OpenRTB Native 1.2). 5 stay `preview` past GA (`html5`, `image_carousel`, `sponsored_placement`, `responsive_creative`, `agent_placement`).
+> - **v1 named formats stay first-class** through 4.x with a 5.0 sunset floor. Dual-emission is the migration mode; SDKs translate either direction. Realistic v2-only buyer-agent timing is 4.x at the earliest.
+> - **15 v1→v2 mapping registry entries at GA, 71+ of audited v1 formats are v1-only** out of the gate (need seller `canonical` field or registry PR to project to v2). v2-aware buyers see meaningfully thinner inventory than v1-aware ones through 3.x. Dual-read codepath realistic through 3.3.
+> - **Phase 4 (SDK codegen) is the gating dependency for adopter consumption.** Schemas are shippable today; the typed-tagged-union ergonomics this design earns land fully only with codegen. The runtime Ajv validator is the load-bearing gate — generated TS/Pydantic types lose `if/then` narrowing on `format_kind: "custom"` and `result_kind`.
+
+> **Status:** Preview track. The canonical-formats surface is being designed in flight against [RFC #3305](https://github.com/adcontextprotocol/adcp/issues/3305) and the [#3307 implementation branch](https://github.com/adcontextprotocol/adcp/pull/3307).
+>
+> *Naming note*: This work was originally drafted as "creative formats v2" — the v1↔v2 contrast describes the two format-authoring models (legacy named-format registry vs new canonical formats on products). To avoid collision with AdCP-the-protocol's own version numbering (currently 3.x), file paths, identifiers, and the body of this doc use **canonical formats** terminology. The v1↔v2 contrast is reserved as schema-description shorthand where it disambiguates the two authoring paths on `Product.format_ids` vs `Product.format_options`.
+
+Canonical formats collapse today's separate format registry into product-bound declarations. AdCP defines a small set of **canonical formats** (universal building blocks); sellers' products carry inline `ProductFormatDeclaration`s that narrow canonicals with platform-specific parameters. Creative agents become transformation services declaring `build_creative` capabilities targeting canonical formats. Most existing concepts (CTAs, destinations, tracking, brand identity) are reused or stay in their current homes — canonical formats don't create a new vocabulary layer for those.
+
+## Glossary
+
+| Term | One-line definition |
+|---|---|
+| **Canonical format** | One of 12 AdCP-defined format archetypes that products narrow (e.g., `image`, `video_vast`, `audio_hosted`, `native_in_feed`). The buyer's stable validation target. |
+| **`format_kind`** | Discriminator value naming a canonical format (e.g., `"image"`). Selects which canonical's parameter schema applies. |
+| **`format_options`** | Array of `ProductFormatDeclaration`s on a v2 product. The 90% case is single-element; multi-element declares "accepts any of." |
+| **`ProductFormatDeclaration`** | Inline format declaration: `format_kind` + `params` + optional `capability_id` + optional `applies_to_channels` + optional `experimental` + optional `v1_format_ref[]` (always array — see below). |
+| **`v1_format_ref`** | Array of `{agent_url, id}` references linking a v2 declaration to one or more v1 named formats. Always array; single-ref is `[{...}]`. Multi-size declarations carry one ref per size (see "Multi-size fan-out" below). |
+| **`canonical:` annotation** | The v1 catalog entry's projection annotation. Always object form — `{ kind: "image" }` minimum, `{ kind, asset_source, slots_override }` rich form for entries whose v1 shape doesn't follow the canonical's defaults (generative, brief-driven). Never bare-string. |
+| **Sibling refinement principle** | Before reaching for a new canonical, check whether `asset_source` + `slots_override` + `applies_to_channels` + event_log surface covers the case. Applied to: generative (image + asset_source: agent_synthesized), broadcast TV (video_hosted + applies_to_channels: ["tv"]), DOOH (image + applies_to_channels: ["dooh"]), native (image + slots_override). No new canonical for any of them. |
+| **`capability_id`** | Stable identifier for a format declaration, used to disambiguate when `format_options` carries multiple declarations sharing the same `format_kind`. |
+| **`applies_to_channels`** | Subset of the product's declared channels this format declaration applies to. Lets multi-channel products carry per-channel format options. |
+| **`experimental`** | Boolean on canonical (`_base.json`) and on `ProductFormatDeclaration`. `true` = may not work as declared; have a v1 fallback ready. Replaces the earlier `status` + `runtime_status` enums (single binary flag rather than two stability axes). |
+| **`slots`** | Programmatic declaration on a format of which `asset_group_id` slots a manifest must (or may) populate, each paired with an `asset_type`. |
+| **`asset_group_id`** | Canonical slot-name vocabulary (e.g., `image_main`, `script`, `landing_page_url`). Replaces v1's free-text `asset_role`. |
+| **`composition_model`** | How the surface composes per-impression: `deterministic` (buyer-predictable per-slot) vs `algorithmic` (surface picks combinations from a pool). |
+| **`synthesis_nondeterministic`** | When true, the production pipeline cannot guarantee in-spec output (Veo/Sora-class). Implies QA-loop + retry semantics. |
+| **`provenance_required`** | When true, the product rejects unsigned synthesized assets. Builders attach C2PA-compatible provenance manifests. |
+| **`platform_extensions`** | URI+digest references to platform-specific extensions narrowing the canonical (pixel ID shapes, conversion event taxonomies). |
+| **`asset_source`** | Production-source declaration: who renders the asset bytes. Single shared 5-value enum across `image` / `video_hosted` / `audio_hosted`. `item_production_model` on `sponsored_placement` covers the same axis with a 4-value subset (drops `publisher_host_recorded`, which is audio-specific). |
+| **`status` on canonicals** | Spec-maturity axis (`stable` / `preview` / `deprecated`). All canonicals are `preview` while v2 itself is in preview; per-canonical promotion to `stable` happens at 3.1 GA based on adopter evidence. |
+| **`since_version` / `migration_target_version`** | Release-precision lifecycle metadata on canonicals — when introduced, when stabilization or breaking revision is expected. |
+| **`validate_input`** | Spec-defined dry-run primitive — buyers verify a manifest against canonicals/products without committing to a render. |
+| **`build_creative`** | Creative-agent surface that produces a manifest from inputs (brief, video_brief, brand). Sales agents do NOT expose `build_creative`. |
+| **`creative.supported_formats`** | Capabilities-response field on creative agents declaring which canonicals they can produce via `build_creative`. |
+| **`BrandRef`** | `{domain, brand_id?}` reference. Resolves brand context (logos, colors, voice) from `brand.json` automatically. |
+| **`brand_kit_override`** | Inline override on `BrandRef` for per-call brand-kit tweaks (logo, colors, voice, tagline) where `brand.json` is missing, stale, or inappropriate. Same pattern as `industries` and `data_subject_contestation` on BrandRef. |
+| **`fanout_mode`** | On `sponsored_placement`: how items map to delivery — `per_item`, `multi_item_in_creative`, `single_item`. |
+| **`item_production_model`** | On `sponsored_placement`: how each per-item creative is produced. Captures multi-output generative (1 brief × N items → N creatives). |
+| **`format_kind: "custom"`** | Adopter-defined shape that doesn't fit the 12 canonicals (multi-placement takeover, branded content, AR lens, etc.). Requires `format_shape` (registry classifier) and `format_schema` (URI+digest reference to a fetchable schema). |
+| **`format_shape`** | Recognized global pattern from the [format-shape vocabulary registry](https://adcontextprotocol.org/schemas/v3/core/format-shape-vocabulary.json). Required when `format_kind: "custom"`. |
+| **`format_schema`** | URI+digest reference to the fetchable schema describing a custom shape's `params` and `slots`. Required when `format_kind: "custom"`. Same hosting model as `platform_extensions`. |
+
+## Architectural shift
+
+| Concept | v1 | v2 |
+|---|---|---|
+| Format identity | Compound `{ agent_url, id }` referencing a separately-defined format file | Canonical name (e.g., `image`) keyed under `format` on the product, narrowed inline |
+| Format authoring | Each platform authors its own named format files | Platforms narrow AdCP-defined canonicals; canonical IS the contract buyers validate against |
+| Format submission contract | Each platform publishes a parallel set of `*_generated_*` format files for AI-produced creative alongside the asset-upload version (~30 duplicate files in agentic-adapters) | The format declares a single `slots` array enumerating everything the buyer ships in the manifest's `assets` map, each entry a canonical `asset_group_id` paired with an `asset_type` (image / video / audio for direct rendering; text / brief / object / url for content the seller consumes for production). Buyer mental model is uniform — one `assets` map, no separate "inputs" concept. **Whether the seller's internal production is generative AI, host recording, transcoding, or asset rendering is invisible to the buyer.** No "generative" category at the protocol level; the production mechanism is implementation detail. |
+| Discovery | `list_creative_formats` (overloaded — used by both sales and creative agents) | `creative.supported_formats` on `get_adcp_capabilities` (uniform replacement, same `ProductFormatDeclaration` shape regardless of agent role); sales agents additionally expose `get_products` for product-level detail with `format` inline |
+| Tracking | Mixed across asset types and format definitions | Baked into each canonical format (VAST events for `video_vast`, MRAID+OM-SDK for `html5`, impression pixel for `image`) |
+| Brand identity | Sometimes redeclared as format slots | Implicit via `brand` (a [`BrandRef`](https://adcontextprotocol.org/schemas/v3/core/brand-ref.json) — `domain` plus optional `brand_id` for house-of-brands) resolving brand.json; explicit override via `brand_kit_override` inline on the BrandRef itself |
+
+## The 12 canonical formats
+
+Each canonical lives at `/schemas/formats/canonical/<name>.json`. Tracking model is **format-specific** (split by tracking model is why we have 12 instead of, say, 5).
+
+| Canonical | What it is | Tracking |
+|---|---|---|
+| `image` | Static image, file or hosted URL redirect | Impression pixel + click URL via `universal_macros` |
+| `html5` | Interactive HTML5 banner (zip asset) | MRAID + OM-SDK + click-tag macro + backup image |
+| `display_tag` | Third-party JS/iframe tag URL | Opaque to seller |
+| `image_carousel` | Multi-card swipe (polymorphic image/video items) | Per-card pixels + carousel engagement |
+| `video_hosted` | Direct video file, orientation parameter | OM-SDK + external impression/click/quartile trackers |
+| `video_vast` | VAST tag (URL or inline XML), VAST 2-4.x | Inherent VAST events |
+| `audio_hosted` | Direct audio file (or host-read produced via build_creative) | Standard audio impression/completion |
+| `audio_daast` | DAAST tag | Inherent DAAST events |
+| `sponsored_placement` | Retail-media catalog-driven (Amazon SP, Criteo SP, CitrusAd SP) — REQUIRES `source_catalog` slot. Not for IAB in-feed native, content-recommendation, or PMax-style algorithmic surfaces. | Per-item catalog-keyed events |
+| `native_in_feed` | IAB-shaped in-feed native and content-recommendation widgets (Taboola, Outbrain, Yahoo Native, AdMob Native, in-feed sponsored cards). Slots map 1:1 to IAB OpenRTB Native 1.2. | Renderer-fired `pixel_tracker` (impression / viewability / click) |
+| `responsive_creative` | Buyer asset pool, surface composes combinations (Google Responsive Display/Search Ads, Performance Max, Demand Gen; Meta Advantage+ creative) | Per-asset performance breakdown |
+| `agent_placement` | Sponsored placement composed by an AI surface in response to a user query (ChatGPT, Perplexity, voice assistants, sponsored search snippets). Distinct from `si_chat` (brand-owned conversation; user → brand's agent). | Mention-level impression + attribution |
+
+### `experimental` — one field, both axes
+
+A canonical (or a seller's specific product declaration) carries a single `experimental: boolean` flag. Same semantics as `experimental` on protocols: 'this is shipping but may break, evolve, or fail.' Buyers reading `experimental: true` SHOULD have a v1 fallback ready and SHOULD validate via `validate_input` or a sandbox before routing production budget. This replaces the earlier two-axis design (`status` + `runtime_status` enums) — collapsed because what buyers actually care about is binary: do I treat this as production-stable, or as use-at-your-own-risk.
+
+`experimental: true` is set at 3.1 GA on four canonicals:
+
+| Canonical | Why experimental | Promotion gated on |
+|---|---|---|
+| `sponsored_placement` | Four meaningfully different retail-media adapter contracts (Amazon SP, Criteo SP / CitrusAd SP, Pinterest Collection, generative-per-SKU) under one canonical | #4592 adapter-contract docs |
+| `responsive_creative` | Algorithmic composition (surface picks combinations); no clean v1-translatable equivalent | Adopter evidence + per-surface conformance |
+| `agent_placement` | Tracking macro vocabulary / postback shape / cross-surface dedup intentionally underspecified for 3.1 | 3.2 tracking-contract spec |
+| `custom` | Inherently experimental — adopter-defined shape until promoted to a first-class `format_kind` | Per-shape promotion via the #3666 queue |
+
+The 7 IAB / VAST / DAAST / IAB-Native re-encodings (`image`, `display_tag`, `video_hosted`, `video_vast`, `audio_hosted`, `audio_daast`, `native_in_feed`) plus `html5` and `image_carousel` ship non-experimental — they're settled industry standards being re-encoded in canonical-formats vocabulary.
+
+Sellers MAY set `experimental: true` at the product-declaration level (on a specific `ProductFormatDeclaration`) even when the underlying canonical is non-experimental — useful for beta runtime paths or forward-looking catalog declarations the seller hasn't wired yet. Buyer SDKs SHOULD filter products with `experimental: true` from default views and offer an opt-in to surface them.
+
+When a seller marks a product `experimental: true`, the buyer's path of least resistance is the v1 fallback: if the v2 declaration carries `v1_format_ref` linking to a v1 named format, ship against v1 until the seller drops the experimental flag. v1 is the safe path; v2 is the surface the seller is still testing.
+
+## Two axes: composition (per-impression) vs production (who renders)
+
+Two orthogonal patterns govern how a creative is produced and how it serves. Conflating them is the most common authoring mistake.
+
+**Composition model** — `composition_model: deterministic | algorithmic` on the format declaration. Describes how the **surface composes per-impression**:
+- `deterministic` — buyer can predict per-slot rendering. The surface serves what it received. (`image`, `video_hosted`, `audio_hosted`, `video_vast`, `audio_daast`, `sponsored_placement`.)
+- `algorithmic` — surface picks combinations from a buyer-supplied asset pool per-impression. The buyer ships a pool; the surface composes. (`responsive_creative` for Google PMax / Meta Advantage+; `agent_placement` for AI-surface composition.)
+
+**Production source** — `asset_source` describes **who renders the rendered asset, and when**:
+- `asset_source` on `image`, `video_hosted`, `audio_hosted` — single shared 5-value enum: `buyer_uploaded | publisher_host_recorded | seller_pre_rendered_from_brief | seller_human_designed | agent_synthesized`. `publisher_host_recorded` is audio-specific (podcast host-read pattern) and meaningful only on `audio_hosted`.
+- `item_production_model` on `sponsored_placement` — same axis, 4-value subset (drops `publisher_host_recorded`), applied per catalog item (the multi-output generative case: 1 brief × N catalog items → N rendered creatives)
+
+The two axes don't collapse. A generative DSP that produces ONE rendered image from a brief is `composition_model: deterministic` (the surface serves what it received) + `asset_source: seller_pre_rendered_from_brief` (seller produced it from inputs at sync_creatives time). A retail-media surface that runs an AI synthesis pipeline per catalog item is `composition_model: deterministic` + `item_production_model: agent_synthesized`. Google PMax is `composition_model: algorithmic` + (production-source unspecified — buyer ships a pool of pre-rendered assets so the production-source question doesn't apply at the format level).
+
+The production-source enums are informational, not the binding contract. The format's `slots` declaration is the contract — what the buyer ships, in what shape. The `asset_source` field tells the buyer "here's how this product produces the rendered creative" so they can pick products whose production model fits their workflow (in-house pre-rendered vs upstream creative agent vs seller-driven generative).
+
+### Tracker assembly under seller-rendered sources
+
+When `asset_source` is `buyer_uploaded`, the buyer ships rendered assets and any tracker URLs attached to those assets are buyer-controlled (universal_macros for impression/click; `vast_tracker` / `daast_tracker` assets for decomposed VAST/DAAST trackers). When `asset_source` is any of the seller-rendered values (`seller_pre_rendered_from_brief`, `seller_human_designed`, `agent_synthesized`) or `publisher_host_recorded`, the buyer never sees the rendered artifact directly. Two normative paths apply:
+
+- **Macro-substituted tracking (default).** The seller honors AdCP universal_macros at impression time — `{IMPRESSION_TRACKER}`, `{CLICK_TRACKER}`, etc. — and substitutes buyer-supplied tracker URLs (declared on the manifest's optional `landing_page_url` and the buyer's measurement-vendor pixels declared via `platform_extensions` on the format, filtered by `extensions[uri].extends === "tracking"`) into the rendered creative's serving template. The buyer registers their measurement pixels client-side; the seller calls them at serve time. This is the dominant path for image / video / audio production where serving and tracking are decoupled.
+- **Sync-creatives tracker block.** For products where the seller produces a serving artifact that embeds tracker URLs directly (e.g., a generated VAST tag or a stitched companion banner), the seller's `sync_creatives` response SHOULD include a `tracker_block` field listing the impression URL pattern and click URL pattern. Buyers register those with their measurement vendor at sync time. This path covers the generative-DSP pattern where the serving artifact and the tracking shape are produced together.
+
+`vast_tracker` and `daast_tracker` decomposed tracker assets work for both `buyer_uploaded` and seller-rendered sources — when the seller renders, those tracker assets are inputs to the rendered tag, attached to the appropriate VAST/DAAST `<TrackingEvents>` block at production time. When the buyer ships a complete `vast` or `daast` tag, the trackers travel inside the tag.
+
+## What `format_kind` is NOT for
+
+`format_kind` names the creative ASSET shape — what the buyer ships, what the surface accepts. It's not for delivery medium, measurement model, or targeting context. Conflating these is the most common architectural mistake a 3.2 contributor will be tempted to make. Three concrete examples:
+
+| Tempting (wrong) | Right answer | Why |
+|---|---|---|
+| `format_kind: "broadcast_video"` | `format_kind: "video_hosted"` + `applies_to_channels: ["tv"]` | The video asset is the same shape. Broadcast vs streaming is a delivery / measurement difference, not a creative-shape difference. |
+| `format_kind: "dooh_image"` | `format_kind: "image"` + `applies_to_channels: ["dooh"]` | The image asset is the same shape. DOOH's location-keyed measurement and no-click model live on `sync_event_sources` / `event_log`, not on the format. |
+| `format_kind: "image_generative"` | `format_kind: "image"` + `asset_source: "agent_synthesized"` + `slots_override: [{ generation_prompt: text }]` | Same canonical TYPE; different production SOURCE. The two-axis model already separates them. |
+
+**Rule of thumb.** Before reaching for a new `format_kind`, check whether the difference is:
+1. **Creative type** (image vs video vs audio vs html5 vs 3p-tag) → `format_kind`, the only knob it controls.
+2. **Production model** (who renders, when) → `asset_source` on the format declaration.
+3. **Slot shape** (what assets the buyer ships) → `slots_override` on the projection ref (catalog side) or on the v2 product's `format_options[]` declaration.
+4. **Delivery medium / channel** (TV vs streaming vs DOOH vs social) → `applies_to_channels` on the v2 product.
+5. **Measurement / tracking / event model.** Splits two ways:
+   - **Renderer-fired trackers** (the renderer hits a URL when serving / viewing / clicking) → `pixel_tracker` asset (or `vast_tracker` / `daast_tracker` on those formats). Lives on the creative manifest as a typed slot. Buyer's measurement vendor URLs the seller's renderer fires at serve time. See `docs/creative/asset-types.mdx#pixel-tracker-asset`.
+   - **Conversion pixels** (fire on the advertiser's site post-click — Meta Pixel, GA4 server-side, custom postbacks) → `sync_event_sources` / `event_log`. Campaign-scoped, NOT creative-asset-scoped. The same pixel fires for every ad in the campaign.
+6. **Targeting context** (audience vs geo vs daypart) → media-buy targeting overlay, not the format.
+
+New `format_kind` only when the CREATIVE ASSET itself is structurally different (e.g., DAI's ad-stitched continuous audio stream is structurally different from `audio_hosted`'s file-per-impression). All 50 ad formats in the v1 catalog at GA project to canonicals via this rule; broadcast TV, DOOH, and generative all stay on existing canonicals (sibling refinement via `applies_to_channels` / `asset_source` / `slots_override`). The one exception is `native_in_feed`: IAB OpenRTB Native 1.2 in-feed and content-recommendation units have an asset-bundle composition shape (title + image + body + CTA assembled by the renderer) that isn't expressible as sibling refinement on `image` or `responsive_creative` and isn't catalog-keyed like `sponsored_placement` — a buyer agent needs the `format_kind` discriminator to route to the right assembly logic. The 12-canonical line is held *because* native_in_feed cleared this bar; it's not a precedent for every channel asking for its own canonical.
+
+## When to use `slots_override` (and when to leave it off)
+
+`slots_override` (on the catalog's `canonical:` projection ref OR on a v2 product's `format_options[]` declaration) replaces the canonical's default slot set with a custom list. Use it sparingly — most formats inherit defaults cleanly.
+
+**Decision rule.** Would a buyer composing a creative manifest list **different assets** in this case vs the canonical's default? If yes, `slots_override`. If no, leave it off.
+
+| Case | Default vs Override |
+|---|---|
+| 300×250 IAB MREC | **Default.** Canonical `image` defaults already carry `image_main: image, required` + headline/body/cta/landing — the buyer's manifest assets are the canonical's defaults. |
+| Native standard (title + description + image + icon + sponsored_by) | **Override.** Adds `brand_name` (`sponsored_by` alias) as required, makes `headline` required, narrows `cta` to enum values. Manifest assets diverge from canonical defaults. |
+| DOOH billboard (image only, no click) | **Default.** Canonical `image` defaults cover it (image_main required, no other required slots). No-click model lives on event_log, not on slots. |
+| Broadcast TV spot (video file + captions URL) | **Default.** Canonical `video_hosted` defaults cover it (video_main required, captions optional). Broadcast trafficking lives on `applies_to_channels: ["tv"]`. |
+| Generative image (text prompt instead of image) | **Override.** Replaces `image_main: image, required` with `generation_prompt: text, required`. Manifest assets are structurally different from canonical defaults. |
+| Podcast host-read (script text instead of audio) | **Override.** Replaces `audio_main: audio, required` with `script: text, required` + `asset_source: publisher_host_recorded`. |
+
+The rule applies symmetrically: if you're tempted to add `slots_override` only to declare measurement pixels, delivery-medium flags, or targeting context, you're using it wrong — those don't belong in slots at all (see "What `format_kind` is NOT for" above).
+
+## Custom formats — shapes the 12 canonicals don't cover
+
+The 12 canonicals cover atomic creative shapes (one image, one video, one display tag, one carousel, one native in-feed unit, one catalog placement, one AI-surface mention). They don't cover composed / coordinated / sponsorship shapes that high-end publishers and broadcast networks sell as headline products: multi-placement takeover, roadblock, branded content, cross-screen sponsorship, sponsorship lockup, newsletter sponsorship, AR lens, playable, live event sponsorship.
+
+These shapes are real ad-industry product types — but they're either multi-canonical compositions (takeover = image + video + display_tag + lockup, sold as a unit) or genuinely novel structures (branded content's editorial-sponsorship production model isn't a composition of the 12). v2 handles them via a structured custom mechanism that buyer agents can reason about, NOT via free-form `ext`.
+
+### The mechanism
+
+```json test=false
+{
+  "format_options": [
+    {
+      "format_kind": "custom",
+      "canonical_formats_only": true,
+      "format_shape": "multi_placement_takeover",
+      "format_schema": {
+        "uri": "https://nytimes.example/schemas/formats/homepage_takeover_v3",
+        "digest": "sha256:e1d4f6a9c2b5e8d1f4a7c0b3e6d9f2a5c8b1e4d7f0a3c6b9e2d5f8a1c4b7e0a3"
+      },
+      "capability_id": "nytimes_homepage_takeover_premium",
+      "applies_to_channels": ["display", "olv"],
+      "params": {
+        "components": [
+          { "placement_type": "homepage_skin", "required": true },
+          { "placement_type": "preroll_video", "required": true },
+          { "placement_type": "sponsorship_lockup", "required": true }
+        ],
+        "exclusivity_window_hours": 24
+      }
+    }
+  ]
+}
+```
+
+Three required pieces when `format_kind: "custom"`:
+
+1. **`format_shape`** — recognized global pattern from the [format-shape vocabulary registry](https://adcontextprotocol.org/schemas/v3/core/format-shape-vocabulary.json). Tells buyer agents what kind of pattern they're looking at (`multi_placement_takeover`, `branded_content`, `ar_lens`, etc.). The registry currently lists 9 shapes; non-canonical values are valid (validators MAY soft-warn) so adopters CAN ship a shape that isn't yet in the registry — adding entries is a vocabulary PR, not a major-version bump.
+2. **`format_schema`** — URI+digest reference to a fetchable schema describing the shape's actual `params` and `slots`. **Same hosting model as `platform_extensions`**: open-ecosystem publishers host the artifact at the canonical URI on their subdomain; closed-platform / walled-garden shapes resolve through the AAO mirror at `https://creative.adcontextprotocol.org/translated/...`. Buyer agents fetch by `uri@digest` (immutable per digest, aggressive caching), validate `params` and `slots` against the fetched schema, and reason about manifests structurally.
+3. **`params`** — the actual structure, governed by the schema fetched from `format_schema.uri`. AdCP doesn't bake the params shape; the seller's schema does.
+
+### `format_schema` fetch contract (normative)
+
+`format_schema` gates validation — without the schema, a buyer cannot reason about the custom shape. The **transport** rules below apply identically to BOTH `format_schema` and `platform_extensions` (any SDK fetching a `platform-extension-ref.json` URI applies the same rules — a shared fetch path that drops to the weakest bar undermines `format_schema`'s hardening). The **consumption** distinction (`format_schema` is load-bearing, `platform_extensions` is informational) is about *what the body means*, not about how it's fetched.
+
+- **Transport**: `https://` only. `http://`, `file://`, `data:`, and other schemes MUST be rejected.
+- **SSRF protection**: resolved hostname MUST NOT land on RFC 1918 (10/8, 172.16/12, 192.168/16), loopback (127/8, ::1), link-local (169.254/16, fe80::/10), CGNAT (100.64/10), or RFC 6761 special-use names (`.local`, `.localhost`, `.internal`, `.test`, `.example`, `.invalid`). Cloud metadata endpoints (`169.254.169.254`, `metadata.google.internal`, `kubernetes.default.svc`) are explicitly forbidden — these are credential-leak primitives. Connection MUST be pinned to the resolved IP (or re-resolved and re-validated per request) to defeat DNS rebinding.
+- **No redirects.** HTTP redirects MUST be disabled on these fetches. Open redirects on same-origin paths are otherwise a free SSRF primitive.
+- **1 MiB response cap.** Enforce during streaming. Over-cap = hard fail.
+- **Digest mismatch is a hard fail.** SHA-256 of the body MUST equal `format_schema.digest` (`sha256:` + 64 lowercase hex). On mismatch, the buyer MUST treat the declaration as unresolvable. No fallback to the unverified body. Sustained mismatch (vs network flap) MUST be distinguishable in telemetry — it's a substitution-attack signal.
+- **Timeout** ≤5s recommended. Timeout treated as a 5xx (transient — retry or skip).
+- **`$ref` sandboxing**: fetched schemas MAY use `$ref`, but only to (a) same-origin URIs after RFC 3986 §6 normalization (lowercase scheme + host, strip default port, no userinfo), (b) the AAO mirror namespace, or (c) intra-document JSON Pointer refs bounded to the parent document. Cross-origin `$ref` to arbitrary URIs MUST be rejected. `$ref: file://...` MUST be rejected. Transitive `$ref` depth ≤8 AND total `$ref` count ≤256 across the resolved tree (depth alone is not enough — depth 8 × breadth 100 = 10^16 nodes).
+- **Schema-compile bounds (DoS protection)**: validators MUST bound CPU/memory. Recommended: compiled-schema keyword count ≤10 000, `pattern` regexes evaluated with `re2` OR under a per-pattern timeout, per-manifest validation budget ≤250 ms (exceeded → invalid + telemetry signal). Without these, a "valid" schema with catastrophic regex backtracking pins a CPU forever.
+- **Cache** by `uri@digest`, immutable. On 404 / partition / persistent failure: skip the declaration for this session, surface via `errors[]`, do NOT fail the whole `get_products` response.
+- **Schema validity**: fetched body must be a valid JSON Schema (Draft 07 or 2020-12). Invalid schema → same as digest mismatch (unresolvable, surface via `errors[]`, skip).
+- **AAO mirror**: `https://mirror.adcontextprotocol.org/*` is a single trust anchor in the allowlist; compromise of the mirror or its CA compromises every buyer agent. Mirror-served bodies are digest-pinned identically to origin fetches. Signed-body + transparency-log hardening is tracked as a 3.2 follow-up.
+
+### Why custom + format_schema instead of `ext`
+
+A buyer agent calling `get_products` and seeing a format with interesting structure buried in `ext` has no spec-level definition to reason against. There's no schema, no required fields, no defined semantics — the agent can see the blob but can't interpret it reliably. A human has to step in to evaluate whether the format fits the campaign brief, what assets are needed, how it tracks, what the impression contract is, whether the price makes sense.
+
+That breaks the load-bearing claim of v2: **buyer agents can reason structurally without per-seller integration code.** ext-only puts interesting structure in a free-form bag, regressing to human-in-the-loop. Custom + `format_shape` + `format_schema` keeps the agentic-first contract: the shape has a registered classifier, the structure has a fetchable schema, the buyer agent reasons over both. Same caching mechanics buyer agents already have for `platform_extensions`.
+
+`ext` remains for genuinely experimental shapes that don't even fit a `format_shape` entry yet — but that's the rare case, not the default. The dominant path for novel shapes is custom + format_shape + format_schema.
+
+### Promotion to canonical
+
+A `format_shape` entry is promoted to a first-class `format_kind` when:
+1. At least 2 production adopters ship it via custom + format_schema
+2. 90 consecutive days without a breaking change to the shape adopters converged on
+3. The shape has a defined tracking model (which signals fire, which trackers attach, what the impression contract is)
+4. The working group opens a per-canonical promotion issue, drafts a canonical schema (`/schemas/formats/canonical/<name>.json`), lands a fixture, and ships in the next minor release
+
+Same governance pattern that produced the 12 canonicals from the v1 audit. The promotion queue lives at [adcp#3666](https://github.com/adcontextprotocol/adcp/issues/3666); current candidates are the 9 entries in the format-shape registry.
+
+**Promotion is a wire-shape change for consumer code.** Any client branching on `format_kind == "custom"` silently stops matching publishers that ship a promoted shape — the seller's product now arrives as `format_kind: "<promoted_name>"`. The normative migration contract (in `format-shape-vocabulary.json`'s description):
+
+1. **Transition window** (≥90 days): sellers MAY emit both shapes simultaneously — `format_options[]` carrying one `format_kind: "custom"` + `format_shape: "<name>"` declaration AND one `format_kind: "<promoted_name>"` declaration.
+2. **Consumer-SDK deprecation warning**: SDKs SHOULD emit a structured deprecation warning via their lint channel (same surface as `FORMAT_PROJECTION_FAILED`) when they see `format_kind: "custom"` with a `format_shape` that's been promoted. Payload: `{ format_shape, promoted_to, promotion_release, transition_end }`.
+3. **`promotion_status` lifecycle**: the registry entry's `promotion_status` updates from `tracking — see adcp#3666` to `promoted to <format_kind> in <version>; transition ends <date>` when the working group schedules promotion. SDKs MAY read this at codegen / runtime.
+4. **Post-transition**: sellers SHOULD drop the legacy `format_kind: "custom"` declaration. Buyers MAY then assume `format_kind == "custom"` is a long-tail / non-promoted shape.
+
+Without this contract, every promotion event silently breaks adopter code; with it, the deprecation warning is the early signal during the transition window.
+
+## Asset group vocabulary
+
+Format `slots` reference canonical `asset_group_id` values from the [vocabulary registry](https://adcontextprotocol.org/schemas/v3/core/asset-group-vocabulary.json). The current canonical entries:
+
+| asset_group_id | asset_type | Common aliases (v1 → v2) |
+|---|---|---|
+| `headlines` | text | headline, title, tagline, headline_text |
+| `long_headlines` | text | long_headline_pool, extended_headlines |
+| `descriptions` | text | description, body, body_text, text, content |
+| `images_landscape` | image | image, hero_image, landscape_image, banner_image |
+| `images_vertical` | image | vertical_image, story_image, portrait_image |
+| `images_square` | image | square_image, feed_image |
+| `image_main` | image | (per-canonical default for `image`) |
+| `logo` | image | brand_logo, logo_image |
+| `video` | video | video_file, hero_video, video_asset, video_main |
+| `video_main` | video | (per-canonical default for `video_hosted`) |
+| `video_vertical` / `video_horizontal` | video | — |
+| `audio` / `audio_main` | audio | audio_file, hero_audio, audio_asset |
+| `companion_image` / `companion_banner` | image | — |
+| `brand_name` / `body_text` | text | — |
+| `cards` | object | carousel_cards, slides, carousel_items, carousel_slides |
+| `cta` | text | cta_text, call_to_action, action_text, button_text |
+| `price` / `phone_number` / `promo_code` / `disclaimer` | text | (various) |
+| `subtitle_file` | url | caption_file, captions, subtitles |
+| `landing_page_url` | url | click_url, link, final_url, link_url, click_through_url |
+| `privacy_policy_url` | url | — |
+| `source_catalog` | catalog | (sponsored_placement) |
+| `hero_asset` | image | hero_banner, collection_hero |
+| `script` | text | script_text, host_script, voiceover_script |
+| `creative_brief` | brief | brief, creative_direction, talking_points |
+| `video_brief` | object | scenes, storyboard, shot_brief |
+| `voice_id` / `offering_ref` | text | — |
+| `style_reference` | image | reference_image, style_image, inspiration_image |
+| `starter_assets` | object | — |
+| `vast_tag` | vast | (video_vast default) |
+| `daast_tag` | daast | (audio_daast default) |
+| `tag_url` | url | (display_tag default) |
+| `html5_bundle` | zip | (html5 default) |
+| `backup_image` | image | (html5 / display_tag default) |
+
+Non-canonical `asset_group_id` values remain valid for platform-specific extensions; validators MAY emit soft warnings on non-canonical IDs to encourage convergence. Aliases are recognized one-way (v1 alias → v2 canonical) when migrating; new manifests SHOULD use the canonical IDs.
+
+## Worked example — Meta Reels
+
+Meta Reels is a useful test of canonical-formats coverage: a platform-specific format from a vendor that hasn't adopted AdCP, with rendering details (CTA enum, primary text, headline limits, brand name overlay) on top of a vertical video. Each Reels feature lands somewhere — canonical `params`, an inherited or overridden slot, the brand layer, the campaign layer — and the canonical doesn't need to grow.
+
+### Where each Reels feature lives
+
+| Reels feature | Where it lives | Notes |
+| --- | --- | --- |
+| Vertical 9:16, 3-90s, 1080×1920, h264/aac, mp4 | `params` on `video_hosted` | Standard canonical parameters. |
+| Headline (40ch), Primary text (125ch) | `params.headline_max_chars`, `params.primary_text_max_chars` + inherited `headline` / `primary_text` slots | Buyer ships text content via the slots; the param narrows the constraint. |
+| CTA from a fixed enum | `params.cta_values[]` + inherited `cta` slot | Buyer ships `assets.cta.text`; validator checks against the enum. |
+| Landing page URL | Inherited `landing_page_url` slot on `video_hosted` | No special handling. |
+| Brand name overlay | NOT in the format. Auto-applied by Meta from the linked Page (auth context outside AdCP). | The inherited `brand_name` slot exists in the canonical; products that need explicit content (publisher-direct video, CTV) populate it. Meta doesn't consume it for Reels. |
+| Logo overlay | NOT in the format. Auto-applied by Meta from the linked Page. | `BrandRef.brand_kit_override.logo` exists for formats whose seller-side renderer overlays a logo (host-read podcasts, CTV bumpers, publisher direct). Meta doesn't use it. |
+| Music overlay (Reels music library) | NOT in this declaration. Would be a `platform_extension` on the format if added; **not present in 3.1** — too platform-specific to be worth a schema seat without 2+ adopters. | Sellers can layer it via `ext` on the manifest in the meantime. |
+| Pixel / conversion tracking | NOT on the format. Conversion tracking is `sync_event_sources` / `event_log` territory — campaign-scoped, not creative-scoped. | The same pixel fires for every ad in the campaign regardless of creative; one declaration in `event_log` covers the campaign. |
+| Placement selection (Feed vs Reels vs Stories) | NOT on the format. Placement is selected at media-buy time (`Placement.format_options[].capability_id`) — pick `meta_reels` to buy Reels, `meta_stories_video` to buy Stories. | They're separate format declarations on the publisher catalog; not a runtime extension parameter. |
+
+### Where to declare a format
+
+Three places. Pick by who owns the assertion.
+
+| Surface | Authority | When to use |
+|---|---|---|
+| `adagents.json` top-level `formats[]` (publisher catalog) | Publisher (or AAO community mirror standing in) | Shared across all sellers of a publisher's inventory — declares the publisher-authoritative shape once. Use `applies_to_property_ids` / `applies_to_property_tags` to scope to a subset of the file's `properties[]`. |
+| `Product.format_options[]` (inline on a product) | Seller, on a specific product | Seller-specific narrowing, custom format, or one-off pricing variant. SHOULD reference a publisher catalog entry by `capability_id` when the publisher has one. |
+| `Placement.format_options[]` (capability_id reference OR inline) | Publisher (or seller publishing placements) | Ties a placement to one or more accepted formats. Reference by `capability_id` (recommended; resolves against the file's top-level `formats[]`) or inline for placement-local narrowing. Same-file scope — cross-file `capability_id` lookup is not supported. |
+
+`applies_to_property_ids` and `Placement.format_options[]` answer different questions: the first scopes a FORMAT to a subset of properties ("Reels applies to Instagram + Facebook but not WhatsApp"); the second binds a PLACEMENT to one or more formats ("Instagram Reels accepts the meta_reels capability"). Property-level format support → `applies_to_property_ids`. Placement-level binding → `placements[].format_options[]`.
+
+### Format discovery (resolution order)
+
+Buyer agents answer "what formats does this publisher accept?" via `list_creative_formats(publisher_domain="<domain>", property_id?="<id>")`. Three-tier resolution:
+
+1. **Publisher-hosted**: fetch `https://<publisher_domain>/.well-known/adagents.json`. If present and carries `formats[]`, return it. Response `source: "publisher"`.
+2. **AAO community mirror**: on 404 or absence-of-formats[], fall back to `https://creative.adcontextprotocol.org/translated/<platform>/adagents.json`. Return its `formats[]`. Response `source: "aao_mirror"`.
+3. **Agent-derived**: if neither tier returns a catalog, the agent synthesizes from the union of its own `Product.format_options[]` over products selling the publisher's inventory. Response `source: "agent_derived"`. Lowest authority — the agent's view of what it sells, not the publisher's catalog. Long-tail IAB publishers without a structured catalog will live here.
+
+**All fetches MUST follow the same transport contract as `format_schema`** — https-only, SSRF guards (RFC 1918 / loopback / link-local / metadata-endpoint denylist; resolve hostname and pin connection to defeat DNS rebinding), ≤5s timeout, 1 MiB cap, no redirects. See `static/schemas/source/core/product-format-declaration.json#format_schema` for the full normative contract. Adagents.json files carry authorization claims + signing keys; SSRF leakage is higher-value to an attacker than format_schema leakage.
+
+**Community-mirror governance** (3.1 status). The AAO publishes adagents.json files for unadopted platforms at `creative.adcontextprotocol.org/translated/<platform>/`. **Maintenance is unowned today** — entries are best-effort, derived from publicly documented platform specs. The community-mirror namespace inherits the same single-trust-anchor concern as the `format_schema` mirror: compromise of `creative.adcontextprotocol.org` or its CA compromises every buyer agent reading the mirror. Signed-body + transparency-log hardening is tracked as a 3.2 follow-up. Until then, buyer SDKs SHOULD treat mirror-served content as advisory (label via `source: "aao_mirror"`), prefer publisher-hosted tier 1 when available, and apply freshness checks (per-platform `OWNERS` + staleness threshold are tracked separately — when a mirror entry hasn't been refreshed within the threshold, the SDK MAY demote its authority to `agent_derived`).
+
+**Identity-confusion note (normative).** A mirror URL in `v1_format_ref[].agent_url` declares *format-shape provenance*, NOT seller identity. Buyer allowlists matching on `v1_format_ref[].agent_url` are matching shape namespace; inventory authorization always flows from `authorized_agents[]` + publisher signing keys. A seller pointing `v1_format_ref` at `creative.adcontextprotocol.org/translated/meta` is asserting "this format follows the AAO-mirrored Meta Reels shape," not "I am Meta."
+
+**Platform-adoption cutover.** When a platform adopts AdCP and publishes its own `adagents.json`, the AAO mirror file SHOULD set `superseded_by: "<platform-domain>/.well-known/adagents.json"`. Buyer SDKs encountering `superseded_by` MUST short-circuit and re-fetch from the named URL rather than serving stale mirror content. The mirror SHOULD continue serving for ≥1 minor release with `superseded_by` set so caches keyed on the mirror URL get an explicit migration signal rather than a silent break. Sellers also update `v1_format_ref[].agent_url` to the platform's adopted agent_url in the same minor release.
+
+### End-to-end fetch flow — buyer's perspective
+
+A buyer agent seeing a `Product` with `publisher_properties[].publisher_domain = "instagram.com"` and needing to know "what formats does this publisher accept, scoped to this property?" walks the following resolution. The pieces are documented separately above; this section walks them in order so adopters don't have to assemble the journey from fragments.
+
+```
+buyer holds: Product { publisher_properties: [{publisher_domain: "instagram.com"}],
+                       format_options: [{capability_id: "meta_reels", ...}, ...] }
+buyer wants: full ProductFormatDeclaration for each format_options entry,
+             scoped to instagram.com's instagram property
+```
+
+**Step 1 — Resolve the publisher catalog.** Buyer SDK fetches `https://instagram.com/.well-known/adagents.json`. Apply the `format_schema` transport contract (https-only, SSRF guards, ≤5s timeout, 1 MiB cap, no redirects — see `product-format-declaration.json#format_schema`). Instagram hasn't adopted AdCP today — fetch returns 404.
+
+**Step 2 — Fall back to AAO community mirror.** On Step 1's 404 (or 200-with-no-`formats[]`), buyer fetches `https://creative.adcontextprotocol.org/translated/meta/adagents.json`. Same transport contract. Response carries `formats[]` with publisher-authoritative declarations. The buyer SDK labels the result `source: "aao_mirror"` for telemetry.
+
+**Step 3 — Check for supersession.** If the response carries `superseded_by`, short-circuit: re-fetch from the named URL (typically the platform's adopted adagents.json) and use that response instead. Today the mirror's `superseded_by` is unset; in the future when Meta adopts, it would point at `https://meta.com/.well-known/adagents.json`.
+
+**Step 4 — Scope by property_id.** From the file's `formats[]`, filter to entries whose `applies_to_property_ids` includes `"instagram"` (the property ID; not the same as `publisher_domain`). Property IDs are declared in the file's top-level `properties[]` block. A `formats[]` entry with no `applies_to_property_ids` / `applies_to_property_tags` scoping applies to ALL properties in the file. For Meta:
+
+- `meta_reels` → applies_to_property_ids: ["instagram", "facebook"] → matches
+- `meta_feed_image` → applies_to_property_ids: ["instagram", "facebook"] → matches
+- `meta_stories_video` → applies_to_property_ids: ["instagram", "facebook"] → matches
+- `meta_feed_carousel` → applies_to_property_ids: ["instagram", "facebook"] → matches
+
+The Product on hand carries `format_options: [{ capability_id: "meta_reels" }]`. The buyer agent now knows the FULL declaration: `format_kind: video_hosted`, vertical 9:16, 3-90s duration, the full Meta CTA enum, plus the `v1_format_ref[]` array for v1-wire dual emission.
+
+**Step 5 — Resolve placement references (if any).** If the publisher catalog includes `placements[]` and a placement carries `format_options: [{ capability_id: "meta_reels" }]`, the buyer resolves the capability_id against the SAME file's top-level `formats[]` (same-file scope; cross-file lookup is not supported by design). When the reference is broken — capability_id not present in `formats[]` — the SDK MUST surface `FORMAT_CAPABILITY_UNRESOLVED` on the response `errors[]` and fail closed for that placement.
+
+**Step 6 — Multi-tier discovery cache.** Buyer SDK caches the file by `<resolved URL>@<sha256>` for the duration the publisher honors (typically `Cache-Control: max-age`, capped at 24h). Subsequent products from the same publisher reuse the cached file without re-fetching.
+
+**Concrete payload sequence** (Meta Reels, scoped to Instagram):
+
+```
+GET https://instagram.com/.well-known/adagents.json
+→ 404
+
+GET https://creative.adcontextprotocol.org/translated/meta/adagents.json
+→ 200 application/json
+{
+  "properties": [{"property_id": "instagram", ...}, ...],
+  "formats": [
+    { "capability_id": "meta_reels", "format_kind": "video_hosted",
+      "applies_to_property_ids": ["instagram", "facebook"],
+      "params": { ... } },
+    ...
+  ],
+  "placements": [...]
+}
+
+(no superseded_by present — use as authoritative for unadopted platform)
+
+filter formats[] by applies_to_property_ids ∋ "instagram":
+→ 4 declarations match
+
+product's format_options carries: [{ capability_id: "meta_reels" }]
+→ resolve capability_id "meta_reels" against formats[] → full declaration
+
+result: SDK knows the full ProductFormatDeclaration for the product,
+        scoped to the right property, with the right v1 dual-emission
+        format_ids[] from v1_format_ref[].
+```
+
+**Response `source` field reports tier**: `"publisher"` if Step 1 returned formats[], `"aao_mirror"` if Step 2 did, `"agent_derived"` if neither and the SDK synthesized from products' own `format_options[]`. Two SDKs hitting the same agent for the same publisher get consistent labeling regardless of which tier produced the list.
+
+### Community-registry hosting
+
+Meta hasn't adopted AdCP, so its `adagents.json` lives at the AAO community-registry mirror, `https://creative.adcontextprotocol.org/translated/meta/adagents.json`. The mirror file declares `formats[]` at the publisher catalog level — one declaration of Meta Reels, scoped to Instagram + Facebook (not WhatsApp), reused across every seller's products. When Meta later publishes its own `adagents.json` at `meta.com/.well-known/adagents.json`, the platform-hosted file takes precedence and the mirror entry deprecates (via the `superseded_by` signal documented above).
+
+```json test=false
+// https://creative.adcontextprotocol.org/translated/meta/adagents.json (excerpt)
+{
+  "contact": { "name": "AdCP Community Registry — Meta translation", "domain": "adcontextprotocol.org" },
+  "properties": [
+    { "property_id": "instagram", "property_type": "mobile_app", "name": "Instagram", ... },
+    { "property_id": "facebook",  "property_type": "mobile_app", "name": "Facebook",  ... },
+    { "property_id": "whatsapp",  "property_type": "mobile_app", "name": "WhatsApp",  ... }
+  ],
+  "formats": [
+    {
+      "capability_id": "meta_reels",
+      "display_name": "Meta Reels (Instagram + Facebook)",
+      "format_kind": "video_hosted",
+      "applies_to_property_ids": ["instagram", "facebook"],
+      "v1_format_ref": [
+        { "agent_url": "https://creative.adcontextprotocol.org/translated/meta", "id": "meta_reels" }
+      ],
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_range": [3000, 90000],
+        "min_width": 1080,
+        "min_height": 1920,
+        "video_codecs": ["h264"],
+        "audio_codecs": ["aac"],
+        "containers": ["mp4"],
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125,
+        "cta_values": ["LEARN_MORE", "SHOP_NOW", "DOWNLOAD", "SIGN_UP", "CONTACT_US", "BOOK_NOW"],
+        "composition_model": "deterministic"
+      }
+    }
+  ],
+  "placements": [
+    {
+      "placement_id": "instagram_reels",
+      "name": "Instagram Reels",
+      "property_ids": ["instagram"],
+      "format_options": [{ "capability_id": "meta_reels" }]
+    },
+    {
+      "placement_id": "facebook_reels",
+      "name": "Facebook Reels",
+      "property_ids": ["facebook"],
+      "format_options": [{ "capability_id": "meta_reels" }]
+    }
+  ]
+}
+```
+
+Buyer SDKs answer `list_creative_formats(publisher_domain="meta.com")` by fetching this file (or `meta.com/.well-known/adagents.json` first; mirror is the fallback) and returning `formats[]`. The whole question "what formats does Meta support" resolves in one round-trip without per-product traversal.
+
+### Product reuses the catalog declaration
+
+A seller's `meta_reels_us` product references the publisher-catalog declaration by `capability_id`, narrowing only the parts specific to that product (geography, pricing). The format shape itself is inherited from `creative.adcontextprotocol.org/translated/meta`:
+
+```json test=false
+{
+  "product_id": "meta_reels_us",
+  "name": "Meta Reels — United States",
+  "publisher_properties": [
+    { "publisher_domain": "meta.com", "selection_type": "all" }
+  ],
+  "channels": ["social"],
+  "format_options": [
+    {
+      "format_kind": "video_hosted",
+      "capability_id": "meta_reels",
+      "v1_format_ref": [
+        { "agent_url": "https://creative.adcontextprotocol.org/translated/meta", "id": "meta_reels" }
+      ],
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_range": [3000, 90000],
+        "min_width": 1080,
+        "min_height": 1920,
+        "video_codecs": ["h264"],
+        "audio_codecs": ["aac"],
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125,
+        "cta_values": ["LEARN_MORE", "SHOP_NOW", "DOWNLOAD", "SIGN_UP", "CONTACT_US", "BOOK_NOW"],
+        "composition_model": "deterministic"
+      }
+    }
+  ],
+  "pricing_options": [
+    { "pricing_option_id": "cpm_floor", "pricing_model": "cpm", "currency": "USD", "fixed_price": 5.50 }
+  ]
+}
+```
+
+The `capability_id: "meta_reels"` tag lets buyer agents recognize this as the same Meta Reels they read from the publisher catalog — the seller didn't reinvent the format, they're selling inventory against the catalog declaration. The buyer's manifest validates against canonical `video_hosted` first (does it satisfy the contract any seller speaking that canonical accepts?), then narrows against this product's specific parameters.
+
+### What lives where (and why)
+
+- **Canonical params** — fields the canonical already defines (dimensions, durations, codecs, CTA enum, char limits). Sellers narrow values; SDKs validate. Tight, codegen-clean.
+- **Canonical slots** — content the manifest carries. `video_hosted` inherits `video_main`, `headline`, `primary_text`, `cta`, `brand_name`, `companion_banner`, `landing_page_url`. Products can override (remove slots the surface doesn't use; mark required; narrow values).
+- **`platform_extensions`** — net-new fields the canonical doesn't recognize, scoped to one platform's renderer (e.g., a hypothetical Reels music overlay carrying track_id + licensing flags). Bundled by URI+digest in `get_products` so buyers fetch once and cache.
+- **`BrandRef` + `brand_kit_override`** — brand context (logo, colors, voice, tagline) consumed by formats whose **seller-side renderer** overlays brand. Host-read podcasts, CTV bumpers, publisher-direct display do consume it. Meta auto-overlays from the linked Page (auth context outside AdCP), so brand_kit_override has no effect for Meta Reels — it's still the right schema location for the cases that DO consume it.
+- **Campaign / event-log surfaces** — conversion tracking (Meta Pixel, GA4, server-side events). These belong on `sync_event_sources` / `event_log` (campaign-scoped, fires per impression regardless of creative). Format declarations carry creative shape; event-log declarations carry tracking configuration. Don't put `pixel_id` in `platform_extensions` on a creative format.
+- **Media-buy surfaces** — placement selection (Feed vs Reels vs Stories). Pick the right format on the publisher catalog (`meta_reels` vs `meta_stories_video` vs `meta_feed_image`); not a per-creative extension knob.
+
+This separation — canonical params + canonical slots + extensions only for net-new fields + BrandRef for brand context + event_log for tracking — is what keeps the 12 canonicals from accumulating per-platform fields. The lint at `tests/canonical-format-conventions.test.cjs` enforces the `v1_format_ref.agent_url` AAO-hosted convention and the slot/param consistency rule.
+
+## Worked example — IAB display (flexible multi-format, multi-size)
+
+A real IAB display placement isn't a single 300×250 image slot — it's a flexible slot that accepts multiple **creative types** (image, HTML5, third-party tag, sometimes native or video-in-banner) at multiple **sizes** (300×250 MREC, 728×90 leaderboard, 970×250 billboard, responsive). The canonical-formats vocabulary models this with two orthogonal mechanisms:
+
+- **`format_kind`** is the creative TYPE — one of `image`, `html5`, `display_tag`, `native`, `video_hosted` — and never carries dimensional identity.
+- **Size lives in `params`** as one of three modes (mutually exclusive):
+  - **Fixed**: `width` + `height` integers — single accepted size (e.g., a 300×250-only legacy slot).
+  - **Multi-size**: `sizes: [{width, height}, ...]` — list of accepted sizes for a flexible slot. Mirrors OpenRTB `banner.format[]`.
+  - **Responsive**: `min_width`/`max_width` + `min_height`/`max_height` — accepted dimensional ranges for slots that adapt to viewport.
+
+A flexible publisher slot becomes **one product with N format_options** — one per creative type — each carrying the appropriate size declaration. Buyers pick the creative type they ship; the size matches one of the listed pairs (or falls within the responsive range).
+
+The example below is the NYTimes Homepage above-the-fold slot: accepts image, HTML5, or third-party tag at any of three IAB sizes. Three format_options, one product, one price.
+
+```json test=false
+{
+  "product_id": "nytimes_homepage_flex_display",
+  "name": "NYTimes.com Homepage Above-the-Fold Display",
+  "publisher_properties": [
+    { "publisher_domain": "nytimes.com", "selection_type": "all" }
+  ],
+  "channels": ["display"],
+  "format_options": [
+    {
+      "format_kind": "image",
+      "capability_id": "nytimes_homepage_image",
+      "params": {
+        "sizes": [
+          { "width": 300, "height": 250 },
+          { "width": 728, "height": 90 },
+          { "width": 970, "height": 250 }
+        ],
+        "max_file_size_kb": 200,
+        "image_formats": ["jpg", "png", "gif"],
+        "ssl_required": true,
+        "cta_values": ["LEARN_MORE", "SHOP_NOW", "GET_OFFER"]
+      }
+    },
+    {
+      "format_kind": "html5",
+      "capability_id": "nytimes_homepage_html5",
+      "params": {
+        "sizes": [
+          { "width": 300, "height": 250 },
+          { "width": 728, "height": 90 },
+          { "width": 970, "height": 250 }
+        ],
+        "max_initial_load_kb": 200,
+        "max_polite_load_kb": 500,
+        "backup_image_required": true,
+        "om_sdk_required": true
+      }
+    },
+    {
+      "format_kind": "display_tag",
+      "capability_id": "nytimes_homepage_3p_tag",
+      "params": {
+        "sizes": [
+          { "width": 300, "height": 250 },
+          { "width": 728, "height": 90 },
+          { "width": 970, "height": 250 }
+        ],
+        "supported_tag_types": ["javascript", "iframe"],
+        "ssl_required": true,
+        "om_sdk_required": true
+      }
+    }
+  ],
+  "pricing_options": [
+    { "pricing_option_id": "cpm_homepage", "pricing_model": "cpm", "currency": "USD", "fixed_price": 22.00 }
+  ]
+}
+```
+
+**What's happening:** one product, three `format_options` entries (one per creative type), each with `sizes[]` carrying the three accepted IAB sizes. Buyer agents read this as "the slot accepts `image` OR `html5` OR `display_tag` at any of `300×250` / `728×90` / `970×250`." The buyer ships ONE creative — they pick which type and which size — and validation checks the manifest's slot `width`/`height` against the appropriate `sizes[]` list for the chosen format_kind.
+
+**Responsive variant.** A responsive slot replaces `sizes[]` with min/max ranges — `min_width: 300, max_width: 970, min_height: 50, max_height: 250` — and accepts any dimensions within the box. Same multi-format pattern; different size declaration. Exactly one size mode (fixed `width`+`height` / multi-size `sizes[]` / responsive ranges) per format_options entry, enforced at the schema layer.
+
+**Seller preference.** When a multi-format product has several `format_options` at the same price, sellers MAY set `seller_preference: "preferred" | "accepted" | "discouraged"` on each entry to hint which the seller would prefer the buyer ship (often because of viewability / measurement / render-quality differences). Soft routing signal — buyer agents respect it when their own constraints don't override.
+
+## Worked example — Podcast 30s host-read
+
+Host-reads are the host-recorded-from-buyer-script pattern. The product declares `audio_hosted` narrowed to publisher-host-recorded mode with `slots` describing what the buyer ships (a `script` text asset; the publisher's host records audio from it):
+
+```json test=false
+{
+  "product_id": "the_daily_30s_host_read_us",
+  "name": "The Daily — 30s Host-Read Pre-roll (US)",
+  "publisher_properties": [
+    { "publisher_domain": "thedailypod.example", "selection_type": "all" }
+  ],
+  "channels": ["podcast"],
+  "format_options": [
+    {
+      "format_kind": "audio_hosted",
+      "params": {
+        "duration_ms_exact": 30000,
+        "audio_codecs": ["mp3", "aac"],
+        "audio_sample_rates": [44100, 48000],
+        "audio_channels": ["stereo"],
+        "loudness_lufs": -16,
+        "asset_source": "publisher_host_recorded",
+        "buyer_asset_acceptance": "rejected",
+        "composition_model": "deterministic",
+        "slots": [
+          {
+            "asset_group_id": "script",
+            "required": true,
+            "asset_type": "text",
+            "max_chars": 800,
+            "description": "Verbatim script the host reads."
+          },
+          {
+            "asset_group_id": "offering_ref",
+            "required": false,
+            "asset_type": "text"
+          }
+        ],
+        "production_window_business_days": 7
+      }
+    }
+  ],
+  "pricing_options": [
+    { "pricing_option_id": "cpm_host_read", "pricing_model": "cpm", "currency": "USD", "fixed_price": 35.00 }
+  ]
+}
+```
+
+The format declaration tells the buyer everything they need to know — no extra capability lookup. The buyer ships a `script` text asset under that slot in the manifest's `assets` map; brand context comes from the manifest's top-level `brand` BrandRef. There is no separate "inputs" map — everything the buyer ships lives in `assets`. The buyer has two flows depending on whether the seller doubles as a creative agent and whether the buyer wants to pre-produce externally.
+
+### Flow 1 — buyer pre-produces (upstream creative agent)
+
+The buyer calls a creative agent's `build_creative` independently, gets back a rendered manifest, and submits that to the seller. Useful when the buyer has a preferred production partner (their in-house studio, AudioStack-style services) or the seller exposes itself as a creative agent.
+
+1. Buyer reads The Daily's product format → sees `slots: [{ asset_group_id: "script", asset_type: "text", required: true }]` declared
+2. Buyer calls `build_creative({ format: <The Daily's audio_hosted narrowing>, assets: { script: { asset_type: "text", content: "..." } }, brand: { domain: "..." } })` on a creative agent — this could be The Daily's own creative-agent surface (if they expose one), or any other agent that declares it can produce this format via its `creative.supported_formats` on `get_adcp_capabilities`
+3. Receives a rendered manifest with audio asset
+4. Submits the rendered manifest via `sync_creatives` to The Daily's sales agent
+
+### Flow 2 — seller produces internally
+
+The buyer submits assets directly to the seller; the seller produces internally (calls its own creative team or an upstream creative agent under the hood) and returns a registered creative.
+
+1. Buyer reads the same product format
+2. Buyer submits via `sync_creatives` with the assets in the manifest (e.g., a `script` text asset under that slot in the `assets` map)
+3. Seller produces internally; how is invisible to the buyer
+4. Returns async status; buyer polls or waits for completion
+
+The format's `asset_source: "publisher_host_recorded"` + `buyer_asset_acceptance: "rejected"` tells the buyer which flows are accepted. For The Daily's host-read, both flows are valid because the publisher's host needs to be the producer in either case — the difference is whether the buyer drives the build call or the seller drives it. Other products might accept Flow 1 only (buyer must pre-produce) or Flow 2 only.
+
+For brief-driven (talking-points-style) host-reads, the same shape applies with a `creative_brief` slot (asset_type `brief`) in place of the `script` slot. Same target format (`audio_hosted`); different slot declaration.
+
+## Worked example — third-party creative agent (Flashtalking + NYTimes display)
+
+The host-read example above is single-actor by necessity: the publisher's host has to be the producer. The opposite case is the multi-actor display path, where the buyer chooses a third-party creative agent independently and ships the produced manifest to the seller. The seller does **not** compose creatives — it just accepts canonical-conformant manifests.
+
+Three actors:
+
+- **Buyer** (Acme DSP) — discovers products, picks a creative agent (out-of-band: brand-side relationships, AAO registry, direct knowledge), submits manifests
+- **Sales agent** (NYTimes) — sells the placement, validates manifests against the canonical its product narrows, doesn't compose creatives, doesn't maintain a list of "approved creative agents" in v2
+- **Creative agent** (Flashtalking) — produces creatives via `build_creative`, declares its own producible catalog via `creative.supported_formats` on its OWN `get_adcp_capabilities`
+
+The buyer chooses the creative agent independently of the seller. Sellers do not declare a list of creative agents in v2 — the v1 `creative_agents[]` recursive-discovery hint on `list_creative_formats` is part of the deprecated v1 surface. Buyers reason about creative-agent ↔ seller-product compatibility client-side: "Flashtalking can produce `image` 300×250 ≤200KB; NYTimes accepts `image` 300×250 ≤200KB; they're compatible."
+
+### 1. Buyer reads NYTimes products
+
+Buyer calls `get_products` on NYTimes. The MREC product narrows canonical `image`:
+
+```json test=false
+{
+  "product_id": "nytimes_homepage_mrec",
+  "format_options": [
+    {
+      "format_kind": "image",
+      "params": { "width": 300, "height": 250, "max_file_size_kb": 200, "ssl_required": true }
+    }
+  ]
+}
+```
+
+The product narrows the canonical; the canonical is what NYTimes commits to validating against. NYTimes does NOT validate against Flashtalking's narrowing — buyers don't need to know which creative agent produced the manifest, and Flashtalking-specific parameters (e.g., a Flashtalking placement ID) live in Flashtalking's platform extensions if at all.
+
+### 2. Buyer calls Flashtalking's `build_creative`
+
+```json test=false
+// POST https://flashtalking.example/build_creative
+{
+  "format": {
+    "format_kind": "image",
+    "params": { "width": 300, "height": 250 }
+  },
+  "brand": { "domain": "acme.example" },
+  "assets": {
+    "creative_brief": { "asset_type": "brief", "content": "Spring sale, 50% off, blue background, urgent CTA." },
+    "landing_page_url": { "asset_type": "url", "url": "https://acme.example/spring" }
+  }
+}
+```
+
+Flashtalking renders an MREC PNG, returns a manifest with the produced asset:
+
+```json test=false
+{
+  "creative_id": "ft_mrec_88299",
+  "manifest": {
+    "format_id": { "agent_url": "https://flashtalking.example", "id": "image_300x250" },
+    "assets": {
+      "image": { "asset_type": "image", "url": "https://cdn.flashtalking.com/ft_mrec_88299.png", "width": 300, "height": 250 }
+    }
+  }
+}
+```
+
+### 3. Buyer ships to NYTimes
+
+Buyer calls `sync_creatives` on NYTimes with the manifest from Flashtalking. NYTimes:
+
+1. Validates the manifest against canonical `image` (300×250, ≤200KB, SSL).
+2. Validates against the product's narrowing (matches — same params).
+3. Does NOT validate against Flashtalking's narrowing — that's the creative agent's contract with the buyer, not the seller's contract.
+4. If valid → creative registered. If not → returns canonical violations (`width` mismatch, `max_file_size_kb` exceeded).
+
+The seller's validation contract is the canonical, not the creative agent. This is what makes the third-party path additive rather than coupled: the buyer can swap creative agents without changing the seller-facing flow.
+
+## Worked example — generative DSP (universalads-class, asset_source: seller_pre_rendered_from_brief)
+
+A generative DSP (universalads, Pencil, AdCreative.ai-shaped tools) is a sales agent that ALSO renders creatives inline at `sync_creatives` time — it is NOT a creative agent the buyer calls separately. The buyer ships a brief plus structured copy; the seller renders ONE image and serves it like any deterministic creative.
+
+```json test=false
+{
+  "product_id": "universalads_brief_driven_display_300x250",
+  "name": "Universal Ads — Brief-Driven Display (300×250)",
+  "publisher_properties": [
+    { "publisher_domain": "universalads.example", "selection_type": "all" }
+  ],
+  "channels": ["display"],
+  "format_options": [
+    {
+      "format_kind": "image",
+      "params": {
+        "width": 300,
+        "height": 250,
+        "max_file_size_kb": 200,
+        "image_formats": ["jpg", "png"],
+        "ssl_required": true,
+        "composition_model": "deterministic",
+        "asset_source": "seller_pre_rendered_from_brief",
+        "buyer_asset_acceptance": "rejected",
+        "production_window_business_days": 0,
+        "slots": [
+          { "asset_group_id": "creative_brief", "asset_type": "brief", "required": true, "max_chars": 500 },
+          { "asset_group_id": "headline", "asset_type": "text", "required": true, "max_chars": 30 },
+          { "asset_group_id": "landing_page_url", "asset_type": "url", "required": true }
+        ]
+      }
+    }
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    { "pricing_option_id": "cpm_brief", "pricing_model": "cpm", "currency": "USD", "floor_price": 8.00 }
+  ]
+}
+```
+
+Buyer's manifest carries the brief, headline, and clickthrough URL — no rendered image asset. Seller's `sync_creatives` produces the rendered MREC PNG and registers it. Two axes: `composition_model: deterministic` (the surface serves what it received), `asset_source: seller_pre_rendered_from_brief` (the seller renders from inputs at sync time). `buyer_asset_acceptance: "rejected"` makes it explicit that the buyer cannot ship a pre-rendered image directly — the production model is brief-driven only.
+
+## Worked example — multi-format product (Flashtalking html5 OR internal display_tag)
+
+A placement that accepts EITHER a third-party-hosted creative OR an internal tag — buyer picks at sync_creatives time by aligning their manifest's `format_kind` (and `capability_id` if needed) to the matching declaration:
+
+```json test=false
+{
+  "product_id": "regional_news_homepage_300x250",
+  "channels": ["display"],
+  "format_options": [
+    {
+      "capability_id": "html5_flashtalking_hosted",
+      "format_kind": "html5",
+      "params": {
+        "width": 300,
+        "height": 250,
+        "max_initial_load_kb": 200,
+        "ssl_required": true,
+        "composition_model": "deterministic"
+      }
+    },
+    {
+      "capability_id": "display_tag_internal",
+      "format_kind": "display_tag",
+      "params": {
+        "width": 300,
+        "height": 250,
+        "ssl_required": true,
+        "composition_model": "deterministic"
+      }
+    }
+  ]
+}
+```
+
+Buyer's manifest, targeting the html5 option:
+
+```json test=false
+{
+  "format_kind": "html5",
+  "capability_id": "html5_flashtalking_hosted",
+  "assets": { "html5_bundle": { /* ... */ }, "backup_image": { /* ... */ } }
+}
+```
+
+**Routing rule for multi-element `format_options`** (normative):
+
+- `format_kind` selects the canonical and its slot vocabulary.
+- `capability_id` is **REQUIRED** on the manifest when the target product's `format_options` contains two or more declarations sharing the same `format_kind` — without it, the seller can't disambiguate which option the buyer is shipping against.
+- `capability_id` is **OPTIONAL** when each `format_kind` in the product's `format_options` is unique (the example above: one html5 entry, one display_tag entry) — `format_kind` alone routes the manifest. Buyers MAY still send `capability_id` as a clarity hint.
+
+In this example each option carries a distinct `format_kind`, so `capability_id` is optional. Including it (as shown) is a recommended habit — it makes the manifest unambiguous to logs, replays, and downstream tooling, and it keeps the buyer-side codepath identical regardless of whether the seller's product has one or many options sharing a kind.
+
+## Worked example — sponsored_placement with item_production_model
+
+A retail-media product that accepts a catalog reference plus a brief, and renders one creative per catalog item at sync time:
+
+```json test=false
+{
+  "product_id": "regional_retailer_generative_offerings",
+  "channels": ["display"],
+  "catalog_types": ["product"],
+  "format_options": [
+    {
+      "format_kind": "sponsored_placement",
+      "params": {
+        "supported_catalog_types": ["product"],
+        "min_items": 5,
+        "max_items": 200,
+        "fanout_mode": "per_item",
+        "supported_id_types": ["sku", "gtin"],
+        "item_production_model": "seller_pre_rendered_from_brief",
+        "composition_model": "deterministic",
+        "slots": [
+          { "asset_group_id": "source_catalog", "asset_type": "catalog", "required": true },
+          { "asset_group_id": "creative_brief", "asset_type": "brief", "required": true, "max_chars": 500 }
+        ]
+      }
+    }
+  ]
+}
+```
+
+`item_production_model: seller_pre_rendered_from_brief` says: for each catalog item, the seller renders ONE creative using the brief plus the catalog item's structured fields (title, image, price). `fanout_mode: per_item` says each item gets its own ad in delivery. Together they capture the multi-output generative pattern (1 brief × N items → N ads) under the existing `sponsored_placement` canonical.
+
+## Validation flow — `validate_input`
+
+Buyers can dry-run a manifest against canonicals and/or specific products without committing to a render. The buyer's manifest below is a v2 manifest (`format_kind: "video_hosted"`); the slot key is the canonical's `asset_group_id` (`video_main`); the asset value carries its `asset_type` discriminator. The buyer asks `validate_input` to check both the canonical contract AND the seller's specific product narrowing in a single round-trip:
+
+```json test=false
+{
+  "manifest": {
+    "format_kind": "video_hosted",
+    "assets": {
+      "video_main": {
+        "asset_type": "video",
+        "url": "https://cdn.acme.example/spring-95s.mp4",
+        "duration_ms": 95000,
+        "width": 1080,
+        "height": 1920
+      }
+    },
+    "brand": { "domain": "acme.example" }
+  },
+  "targets": [
+    { "kind": "canonical", "id": "video_hosted" },
+    { "kind": "product", "id": "meta_reels_us" }
+  ]
+}
+```
+
+Response carries per-target results. The canonical accepts the duration (canonical `video_hosted` doesn't constrain duration — products narrow); the Meta Reels product narrows duration to `[3000, 90000]` ms, so 95000 is out of range and the product target fails:
+
+```json test=false
+{
+  "results": [
+    {
+      "target": { "kind": "canonical", "id": "video_hosted" },
+      "result_kind": "validated_pass"
+    },
+    {
+      "target": { "kind": "product", "id": "meta_reels_us" },
+      "result_kind": "validated_fail",
+      "violations": [
+        {
+          "rule": "duration_ms_range",
+          "expected": "3000-90000",
+          "predicted": 95000,
+          "field": "assets.video_main.duration_ms"
+        }
+      ]
+    }
+  ]
+}
+```
+
+`validate_input` is the predictable-case primitive. For genuinely nondeterministic synthesis (Veo / Sora / Runway-class), predictive validation is impossible and the platform's own post-synthesis QA loop applies — submission returns `task_failed` with a `synthesis_failed` reason if the QA loop exhausts without producing a valid artifact. There is **no protocol state for orphaned out-of-spec artifacts**.
+
+### When to use `validate_input`
+
+A decision rule, not a one-size primitive:
+
+- **Pre-flight before an expensive `build_creative` call.** If the manifest can't even narrow against canonical, the buyer saves the synthesis cost. Especially relevant for nondeterministic-synthesis products where each retry has real GPU cost.
+- **Multi-target dry-run during product selection.** A buyer comparing 10 candidate products asks `validate_input` once with all 10 product_ids; gets back per-target results. Cheaper than 10 separate `sync_creatives` round-trips.
+- **Debugging a rejected manifest.** When `sync_creatives` returns violations, calling `validate_input` against the canonical alone narrows the question to "is my manifest fundamentally broken vs is the product's narrowing the gating constraint."
+- **Preview-render gating** (formats with `composition_model: algorithmic` or `synthesis_nondeterministic: true`). The platform's preview surface is a richer follow-on; `validate_input` is the cheap pre-flight that gates whether previewing is even worth attempting.
+
+When NOT to use `validate_input`:
+
+- For a manifest you intend to submit anyway. `sync_creatives` returns the same violations and registers on success — `validate_input` adds a round-trip without reducing total work.
+- For products where the seller's narrowing is unknowable client-side without fetching extensions. `validate_input` pulls extensions same as `sync_creatives` does — there's no discovery shortcut.
+- For high-volume per-impression decisions. `validate_input` is per-target, not per-impression. Operational scale (hundreds of products × N format_options) belongs to client-side filtering against the cached `get_products` response.
+
+### `validate_input` vs `build_creative` vs `sync_creatives`
+
+| Tool | Who calls | What it does | Side effects |
+|---|---|---|---|
+| `validate_input` | Buyer | Dry-run validation against canonicals and/or products. Returns per-target `ok` + violations. | None (no creative registered, no synthesis triggered). |
+| `build_creative` | Buyer (calling a creative agent) | Produces a creative manifest from inputs (brief, video_brief, brand). For deterministic flows: one round-trip. For nondeterministic flows: returns task with QA-loop semantics. | Synthesis happens; output manifest is returned. May register a creative on the creative agent's library if the agent supports `has_creative_library`. Does NOT register on the seller. |
+| `sync_creatives` | Buyer (calling a seller) | Submits a manifest to the sales agent for the seller to register against a product. | Validates against canonical + product narrowing; registers creative on the seller's library on success; returns violations on failure. |
+
+For the third-party creative-agent flow: `validate_input` first (cheap pre-flight) → `build_creative` on the creative agent → `sync_creatives` on the sales agent. For the in-house pre-rendered flow: skip `build_creative`; `validate_input` then `sync_creatives`. For the seller-renders-from-brief flow (universalads-class): skip `build_creative` (the seller does the rendering at `sync_creatives` time); `validate_input` then `sync_creatives` directly.
+
+See [`build_creative` task reference](/docs/creative/task-reference/build_creative) for the full request/response shape.
+
+### Discovery + validation at scale
+
+A high-product-count buyer (TTD-class with ~100s of products per get_products response) cannot pre-flight every product via `validate_input` per round — N products × M format_options × per-target round-trips becomes operationally expensive. Two patterns address this:
+
+- **Client-side filtering against the cached `get_products` response.** Buyers who know their manifest's `format_kind` and parameter bucket (canonical, dimensions, duration) filter the product list client-side before validating. The format declarations are already inline on each product — buyers don't need a separate fetch to filter. This is the dominant pattern for "validate against the products that could possibly accept my creative" and reduces the validate_input set by an order of magnitude.
+- **Multi-target `validate_input`.** When the filtered set is still wide (5-50 products), call `validate_input` once with all candidate product_ids in `targets[]`. The response carries per-target results in a single round-trip. Cheaper than per-product calls and structurally aligned with the schema (one request, many results).
+
+For genuinely high-volume scenarios (hundreds of candidate products, real-time bidding pre-flight), buyers should rely on cached `get_products` responses + client-side filtering as the primary path; `validate_input` is reserved for the narrowed candidate set or for debugging unexpected rejections. The `applies_to_channels` field on each format_options element narrows further when a product spans multiple channels.
+
+## Preview as the universal "what does this produce" surface
+
+Buyers ship assets per the format's `slots` declaration; `preview_creative` shows what the output renders as. The seller's response to a creative submission can also include a preview URL — the buyer doesn't need a separate preview call to verify that their submission produced the intended output. Same surface, two production paths:
+
+- **Direct rendering**: buyer ships finished creative assets (image, video, audio) → seller renders them on the placement → preview shows the rendered output (with seller-side composition, overlays, CTA buttons applied).
+- **Seller-side production**: buyer ships content the seller consumes (script text, creative_brief, voice_id selection) → seller produces the rendered asset internally (host recording, generative AI synthesis, transcoding — invisible) → preview shows the produced output.
+
+The buyer can iterate on shipped assets and inspect previews before committing to a buy. Different sellers may produce differently internally; the preview surface is uniform. This is what makes "production mechanism is invisible to the buyer" workable in practice — the buyer doesn't need to know HOW the output was produced because they can see WHAT was produced.
+
+## Brand identity via brand.json (with override)
+
+v2 formats no longer redeclare `brand_logo`, `brand_colors`, `brand_voice`, `brand_tagline` as explicit slots. When a manifest carries a [`BrandRef`](https://adcontextprotocol.org/schemas/v3/core/brand-ref.json) like `brand: { domain: "acme.example" }` (or with `brand_id` for house-of-brands), the seller fetches `https://acme.example/.well-known/brand.json` for brand context.
+
+For the case where brand.json is missing or stale, the BrandRef itself carries an inline `brand_kit_override`:
+
+```json test=false
+{
+  "format_kind": "image",
+  "assets": {
+    "image_main": { "asset_type": "image", "url": "https://cdn.acme.example/banner.jpg", "width": 300, "height": 250 }
+  },
+  "brand": {
+    "domain": "acme.example",
+    "brand_kit_override": {
+      "logo": { "asset_type": "image", "url": "https://cdn.acme.example/logo-2026.png", "width": 200, "height": 100 },
+      "colors": { "primary": "#0066CC", "accent": "#FF6600" },
+      "tagline": "Spring savings, all season"
+    }
+  }
+}
+```
+
+Override fields take precedence over `brand.json` for the call carrying this BrandRef. The pattern matches BrandRef's existing inline overrides (`industries`, `data_subject_contestation`) — brand.json is canonical; inline overrides are per-call. Adopters needing to override brand-kit fields outside this subset (`voice_attributes`, `prohibited_terms`) MUST publish a different brand.json and reference it via a different `domain`.
+
+## Platform extensions — distribution
+
+Platform extensions are narrow, truly platform-specific additions (pixel ID shapes, conversion event taxonomies, platform-specific CTAs/destinations). They live at well-known paths on the owning agent:
+
+```
+https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel
+https://tiktok.example/extensions/tiktok_pixel
+https://nytimes.example/extensions/nytimes_om_strict
+```
+
+Each extension's response carries the schema, the canonical pattern or slot it extends, a version, and a content digest.
+
+**Hosting paths — two separate flows.** v2 supports two hosting models, depending on whether the canonical URI's owner participates in the open AdCP ecosystem or operates as a closed platform that AAO translates on its behalf.
+
+*Open-ecosystem path (publisher-hosted)*. Used when the publisher owning the URI subdomain participates directly in AdCP — independent publishers, SSPs, retail-media networks running their own canonical extensions. The publisher hosts the artifact at the canonical URI on their subdomain. Because URIs are digest-pinned (`uri@sha256:…`), responses are immutable per digest — publishers SHOULD serve them with `Cache-Control: public, max-age=31536000, immutable` and target ≥99.9% / 30-day availability. SDKs cache aggressively by `uri@digest`; a hit is always correct. On 404 or resolution failure, buyers MUST degrade gracefully (treat as unavailable, skip platform-specific narrowing, don't fail the buy).
+
+*Closed-platform path (AAO-translated)*. Used for walled gardens (Meta, Google, Amazon, TikTok, Snap, Pinterest). These platforms are unlikely to host AdCP-shaped extension artifacts on their own subdomains (they have native SDKs and APIs that protect their revenue model; serving an immutable extension CDN gives them no benefit). Instead, AAO runs a translator that maps closed-platform format documentation into AdCP extension artifacts and hosts them under an AAO mirror namespace (e.g., `https://creative.adcontextprotocol.org/translated/<platform>/<artifact>@<digest>`). Worked-example fixtures in this repo that reference `https://creative.adcontextprotocol.org/translated/meta/extensions/...` are illustrative — production usage of those extensions should resolve through the AAO mirror until/unless Meta participates directly. AAO commits to the same digest-pinning + immutability contract; refresh cadence and translation methodology are documented at `https://adcontextprotocol.org/registry/translated-extensions`. Buyers cache and resolve identically across both paths — `uri@digest` is the cache key, regardless of who hosts.
+
+The two paths share the digest-pinned cache and graceful-degradation semantics. They differ only in the resolution authority. The mirror is normative for closed-platform extensions (not "best effort") because there is no other path; for open-ecosystem extensions, the mirror is opt-in fallback.
+
+**Distribution path: bundled in `get_products`.** The sales agent's response includes definitions for every extension referenced by any product in the response, keyed by `uri@digest`:
+
+```json test=false
+{
+  "products": [ { "...": "..." } ],
+  "extensions": {
+    "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel@sha256:a3f5...": {
+      "extends": "tracking",
+      "fields": {
+        "pixel_id": { "type": "string", "required": true },
+        "conversion_event": { "type": "string", "enum": ["PURCHASE", "LEAD"] }
+      },
+      "version": "2.1.0"
+    }
+  }
+}
+```
+
+Buyer's SDK caches by URI@digest. Subsequent `get_products` responses can reference by digest alone if the buyer has the extension cached. Direct URI fetch is supported for tooling but the primary path is bundled-in-`get_products`.
+
+## Dual emission and v2↔v1 projection (normative)
+
+Products MAY carry both `format_ids` (v1) and `format_options` (v2) during the migration window. When both ship, the two MUST refer to the same underlying format declaration — divergent shapes are a contract violation.
+
+### Producer rules
+
+- SDKs that derive both shapes from a single source guarantee the invariant. Hand-authored products MUST be reviewed for agreement.
+- A producer that cannot guarantee agreement MUST emit one shape only.
+- For `format_kind: "custom"` declarations, producers MUST set `canonical_formats_only: true` and MUST NOT synthesize a v1 `format_id`. The protocol does NOT mint synthetic format_ids (an `aao-synth/*` namespace was considered and rejected — adopters would index on identifiers with no stable identity).
+- For `format_options` declarations whose canonical/parameter shape has no clean v1 named-format equivalent (e.g., a structural shape not in `v1-canonical-mapping.json` and not declared on any v1 file), producers SHOULD set `canonical_formats_only: true` rather than emit only one of the two shapes silently.
+
+### Consumer rules (v1→v2)
+
+When reading a product on the v1 path, SDKs project `format_ids` to `format_options` using the resolution order from `v1-canonical-mapping.json`:
+
+1. **Authoritative v2 → v1 link**: if any v2 `ProductFormatDeclaration` on the same product carries `v1_format_ref` pointing at this v1 `format_id`, use that v2 declaration directly. Highest priority — seller asserts the link.
+2. **Seller-asserted on the v1 file**: explicit `canonical` field on the v1 format declaration.
+3. **Registry glob**: `format_id_glob` match.
+4. **Structural match**: registry structural-shape match.
+5. **Fail closed**: SDK MUST NOT synthesize a `format_options` entry. SDKs MUST augment the response's `errors[]` array with an entry carrying `source: "sdk"`, `sdk_id`, `code: FORMAT_PROJECTION_FAILED`, and the field+details (see error-code.json). Single mandated surface — lint-output channels are NOT acceptable; the multi-hop agent network needs warnings to propagate across SDK boundaries via the wire response. The advisory is non-fatal: the response stays 200/success, the product is still valid on the v1 path, only the v2 `format_options` projection is absent.
+
+### Consumer rules (divergence detection)
+
+When a product carries BOTH `format_ids` and `format_options` and the two disagree (different canonical, different dimensions, different orientation, etc.):
+
+- SDKs MUST treat this as a producer contract violation.
+- SDKs MUST prefer `format_options` (canonical formats are the richer surface) and MUST surface the divergent product via `errors[]` augmentation with `source: "sdk"`, `sdk_id`, and `code: FORMAT_DECLARATION_DIVERGENT`. Single mandated surface — lint-output channels are not acceptable. Hard-failing the entire `get_products` response is discouraged — it punishes downstream buyers for a producer bug.
+- SDKs MUST NOT silently pick one shape and discard the other without surfacing the divergence to the calling agent.
+
+The schema cannot enforce agreement (no cross-field constraint expresses "the v1 mapped form of `format_ids[i]` must equal `format_options[j]`"). Consumer-side detection is the only line of defense; SDK conformance suites SHOULD include divergence fixtures.
+
+### "Narrows" — formal definition (normative)
+
+When the spec says a v2 `format_options` entry MUST refer to the same underlying declaration as a v1 `format_ids` entry on the same product (dual-emission invariant), or when an SDK compares an authored v2 declaration against the registry-projected one to detect divergence, the comparison MUST follow this definition:
+
+**v2.params *narrows* the v1-projected baseline** when every parameter present on v2.params is structurally a subset of the equivalent v1 requirement after registry expansion. Specifically:
+
+- **Scalar constraints**: a v2 scalar value `narrows` a v1 range when the v2 value is contained within the v1 range. `v2.width: 300` narrows `v1.width_range: [200, 400]`; `v2.duration_ms_exact: 30000` narrows `v1.min_duration_ms: 3000`.
+- **Enum constraints**: v2.enum_value is a `narrowing` if it appears in v1.allowed_values (or v1.allowed_values is absent — open enum). `v2.image_formats: ["jpg", "png"]` narrows `v1.image_formats: ["jpg", "png", "gif", "webp"]`.
+- **Range constraints**: v2.range narrows v1.range when v2's lower bound ≥ v1's lower bound AND v2's upper bound ≤ v1's upper bound. `v2.duration_ms_range: [5000, 30000]` narrows `v1.duration_ms_range: [3000, 90000]`.
+- **Absent v2 parameter**: when v2.params omits a parameter that v1 specified, v2 inherits v1's value (no narrowing constraint added). Producers SHOULD omit rather than restate v1 defaults.
+- **Asymmetric narrowing**: when v1 says nothing about a parameter but v2 specifies one (e.g., v1 has no `image_formats` constraint, v2 declares `image_formats: ["jpg"]`), v2 is `narrowing` against the implicit "any value" v1 baseline. This is the expected v2-tightens-v1 pattern.
+- **Conflict**: any v2 parameter value that falls outside the corresponding v1 constraint is a *conflict*, not narrowing. SDKs MUST treat conflict between dual-emitted shapes as divergence and surface via `FORMAT_DECLARATION_DIVERGENT`.
+
+The narrows relation is one-directional: v2 narrows v1 (v2 is the stricter shape). The reverse (v1 narrows v2) is NOT how the dual-emission contract is checked.
+
+SDK authors implementing the narrowing check SHOULD apply parameter-by-parameter subsumption per the rules above. Edge cases (composite parameters, platform_extensions, slot vocabulary changes) are not yet specified; SDKs MAY treat them as "unknown — pass" for 3.1 and surface a structured warning, with the working group tightening them per adopter feedback through 3.x.
+
+### v1 → v2 projection via `canonical:` annotation (object shape)
+
+The v1 catalog's `canonical:` annotation is an OBJECT, not a string. The minimal form carries just the canonical kind; the rich form adds `asset_source` and `slots_override` for v1 entries whose shape doesn't follow the canonical's defaults.
+
+**Why an object.** A bare-string annotation `canonical: "image"` implicitly carries the canonical's default slot set (`image_main: image, required`) and default asset_source (`buyer_uploaded`). For v1 entries that follow those defaults — a 300×250 image upload — that's correct. For v1 entries that DON'T (generative, brief-driven, host-recorded), the bare annotation is lossy: an SDK projecting `display_300x250_generative` with bare `canonical: "image"` would produce a v2 declaration claiming buyer-uploaded image bytes, when the v1 entry actually wants a `generation_prompt: text` input. v2-aware buyers reading the projection would mis-route. The object form fixes this.
+
+**Two cases.** Default-slot case (most v1 entries):
+
+```json
+"canonical": { "kind": "image" }
+```
+
+Override case (generative entries, brief-driven host-reads, anything whose v1 asset shape isn't the canonical's default):
+
+```json
+"canonical": {
+  "kind": "image",
+  "asset_source": "agent_synthesized",
+  "slots_override": [
+    { "asset_group_id": "generation_prompt", "asset_type": "text", "required": true }
+  ]
+}
+```
+
+**Projection rules** (per `canonical-projection-ref.json`):
+
+1. `kind` → `format_kind` on the projected v2 ProductFormatDeclaration.
+2. `asset_source` (if set) → `params.asset_source`. If absent, projection uses the canonical's default (typically `buyer_uploaded`).
+3. `slots_override` (if set) REPLACES the canonical's default `slots[]` on the projected declaration. If absent, projection inherits the canonical's defaults.
+4. v1 entry's `requirements` (dimensions, durations, codecs) → `params` fields per the canonical's parameter schema.
+5. v1 entry's `assets[*]` MUST be consistent with the resulting `slots[]` — `asset_id` ↔ `asset_group_id` (asset-group-vocabulary resolves aliases).
+
+**Generative formats in the catalog.** The 8 `display_*_generative` entries carry the rich form with `asset_source: agent_synthesized` and a `generation_prompt: text` slot override. v2-aware buyers projecting these get a v2 declaration that correctly says "this is a 300×250 image format, produced by agent synthesis, buyer ships a text prompt as input." A buyer with image bytes can't satisfy that contract; a buyer with a generation prompt can. The same canonical kind (`image`) supports both because `asset_source` + `slots_override` discriminates on the production model.
+
+**"How does a seller say 'I don't do generative'?"** They already have — by declaring `format_kind: image` with default slots (no `asset_source` override). The canonical's required `image_main: image` slot excludes generative buyers automatically. To OPT INTO generative, the seller declares `asset_source: agent_synthesized` and overrides `slots[]` on their product's format_options entry. Default behavior is the conservative one.
+
+### v2 → v1 linking via `v1_format_ref`
+
+When a seller has both a published v1 named format AND a v2 declaration for the same underlying product/inventory, the v2 declaration carries `v1_format_ref: [{ agent_url, id }]` (always an array) linking back to one or more v1 identifiers. The v2 declaration is the source of truth for shape; the v1 format file stays a pure v1 shape — no mirrored declaration.
+
+#### Multi-size fan-out (normative)
+
+A multi-size v2 declaration with `params.sizes: [{w,h}, ...]` of N entries SHOULD carry one `v1_format_ref[]` entry per size — N v1 named formats covering the N sizes. v1-only buyers then see the product on all sizes via the dual-emitted `format_ids[]`.
+
+When the seller asserts fewer refs than sizes (`v1_format_ref[].length < sizes[].length`), two cases:
+
+- **SDK does NOT fan out (default normative behavior).** Emit `format_ids[]` carrying only the seller-asserted refs (size loss is real but bounded). MUST also emit `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` on the response `errors[]` with `error.details: { product_id, declared_sizes, covered_sizes, dropped_sizes }` so v1-aware downstream agents see what coverage was lost. The lossy emit is the **conservative wire shape** — exactly what the seller asserted, no synthesis.
+- **SDK DOES fan out (MAY-do, non-normative).** For each entry in `sizes[]` lacking a corresponding `v1_format_ref`, the SDK MAY consult the AAO catalog and look up the per-size v1 named format (e.g., for `{width: 728, height: 90}` → `display_728x90_image`). When the lookup succeeds, the SDK MAY emit the catalog-resolved ref under `format_ids[]` alongside the seller-asserted refs. SDKs that fan out MUST still emit `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` as a transparency advisory so downstream consumers know which `format_ids[]` entries were seller-asserted vs catalog-resolved. The advisory's `error.details` SHOULD include `synthesized_refs: [<list of catalog-resolved ids>]`.
+
+**Why MAY-do, not MUST-do or MUST-NOT-do.** SDKs without catalog access can't fan out; making it MUST creates an SDK-feature dependency. Making it MUST-NOT discards real value (a catalog with all three IAB sizes can losslessly expand a multi-size declaration). MAY-do with mandatory advisory preserves SDK choice while keeping the wire shape transparent — downstream consumers can always distinguish synthesized refs from seller-asserted ones via the advisory's `synthesized_refs`.
+
+**Inter-SDK convergence rule.** Two SDKs processing the same input MAY produce different `format_ids[]` (one fans out, one doesn't), but both MUST emit `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` with consistent `declared_sizes` / `covered_sizes` / `dropped_sizes`. Buyer agents reading the response stream can reconcile divergent `format_ids[]` against the advisory.
+
+```json test=false
+{
+  "format_kind": "custom",
+  "format_shape": "multi_placement_takeover",
+  "format_schema": { "uri": "https://nytimes.example/schemas/formats/homepage_takeover_v3", "digest": "sha256:..." },
+  "v1_format_ref": [{ "agent_url": "https://nytimes.example", "id": "homepage_takeover" }],
+  "params": { ... }
+}
+```
+
+This replaces the earlier `canonical_parameters` field on v1 `format.json` files (which is deprecated in 3.1 and removed at 4.0). The directional link from v2 → v1 captures the same fact without the parallel-shape drift surface — v1 files no longer mirror the v2 shape.
+
+`v1_format_ref` is mutually exclusive with `canonical_formats_only: true` — a declaration either has a v1 home (linked via `v1_format_ref`) or doesn't (asserted via `canonical_formats_only: true`). For `format_kind: "custom"` declarations, exactly one of the two MUST be set.
+
+### v2-only declarations on the wire
+
+A buyer reading a product on the v1 wire path sees `format_options` entries with `canonical_formats_only: true` absent from `format_ids`. This is intentional and not a producer error. v2-aware buyers reading `format_options` see them. v1-only buyers see fewer options on `format_ids` than a v2-aware buyer sees on `format_options` for the same product — the v1 surface is a strict subset on these products until v1 sunset (5.0).
+
+### v2-native sellers emitting to v1 buyers
+
+For v2-native sellers whose products do NOT carry preexisting v1 named formats (e.g., a seller that came up after canonical-formats stabilized and authored only `format_options`), the question of what to put in `format_ids` for v1-only buyers has two acceptable answers:
+
+1. **Default — set `canonical_formats_only: true`, omit from `format_ids`.** v1 buyers see no `format_ids` entry for these declarations. The product is functionally invisible to v1-only buyers, but the v1 surface stays clean (no synthetic identifiers polluting buyer-side allowlists).
+2. **Synthesize seller-scoped IDs.** When a seller wants v1-only buyer reach, they MAY mint `format_ids` like `<seller_domain>/canonical_<format_kind>_<param_summary>` (e.g., `acme.example/canonical_image_300x250`). When synthesizing:
+   - The IDs MUST be seller-scoped (under the seller's own `agent_url`), never under `aao-synth/*` or any cross-seller namespace — the AAO-mirror-style synthetic namespace was considered and rejected because adopters would index on identifiers with no stable identity.
+   - The IDs MUST be declared in the seller's published format catalog (the static format file referenced by their adcp-resource manifest, the same place `list_creative_formats` reads from) so v1 buyers see consistent identifiers between `Product.format_ids` and the seller's format directory.
+   - The `format_kind_<param_summary>` convention is a recommendation, not a normative requirement — sellers MAY use any naming convention scoped to their own `agent_url` namespace. Buyers MUST NOT pattern-match on the convention for routing (the seller's catalog is authoritative).
+   - The synthetic `format_ids` entry and the corresponding `format_options` entry MUST satisfy the same dual-emission narrowing contract as any other dual-emitted product (see the projection rules above).
+
+Sellers SHOULD pick option (1) as the default and only opt into (2) when they have a concrete v1-buyer relationship to preserve. Option (2) carries the catalog-sync burden indefinitely; option (1) accepts thinner v1 reach as the cost of a cleaner surface.
+
+## What's NOT in v2
+
+By design, v2 doesn't introduce new vocabulary for things AdCP already handles or that belong elsewhere:
+
+- **Brand safety vocabularies** — that's media-buy/campaign-level (`creative-policy.json` and broader campaign settings), not creative-format-level. Format declarations don't redeclare brand safety.
+- **Universal macros as a new schema** — already documented at [`/docs/creative/universal-macros`](/docs/creative/universal-macros). Canonical formats reference them by name.
+- **`destination_kinds` as a new schema** — `url-asset.json` already has `url_type` covering URL kind disambiguation. Platform-specific destinations (Meta `messenger_thread`, etc.) are platform extensions.
+- **`cta_vocabulary` as a canonical pattern** — CTAs vary meaningfully across surfaces; we let products declare `cta_values` arrays inline until cross-platform demand emerges.
+- **`list_build_capabilities` as a separate tool** — folded into `get_adcp_capabilities` under `creative.supported_formats`.
+- **`build_capability`, `build_capability_ref`, and a separate `inputs` map** — collapsed into the canonical `slots` model on the format declaration. The format declares slots (canonical `asset_group_id` + `asset_type` + constraints); the manifest has a single `assets` map keyed by slot name; the seller dispatches per the format (render assets verbatim or consume them for production). The format itself tells the buyer what it requires; how production happens is implementation detail.
+
+### Channels covered by sibling refinement (no new canonical)
+
+The 12 canonicals cover display, video, audio, native in-feed, retail-media, AI-surface, and responsive-creative archetypes. Several channels look like they want their own canonical but don't — they're covered by **sibling refinement**: the same canonical's `asset_source`, `slots_override`, or `applies_to_channels` axis handles the difference.
+
+- **Linear / addressable TV** — `video_hosted` + `applies_to_channels: ["tv"]`. Asset is still a video file with size/codec/duration constraints. The GRP/spot transaction model and addressable household targeting are media-buy + measurement concerns, not creative-format concerns.
+- **OOH / DOOH** — `image` (or `video_hosted`) + `applies_to_channels: ["dooh"]`. Asset is still a still image (or short video) with size constraints. Location-keyed measurement (Geopath, COMMB) belongs on `sync_event_sources` / `event_log`, not on the format.
+- **Generative-from-prompt** — same `format_kind` as the buyer-uploaded equivalent (image, video_hosted, audio_hosted) + `asset_source: agent_synthesized` + `slots_override` declaring the input shape (`generation_prompt: text`, `creative_brief: brief`, `video_brief: object`). v2-aware buyers see "this format wants a text prompt or structured brief, not image bytes."
+- **Video native** — `video_hosted` + `applies_to_channels: ["native"]`. The asset is still a hosted video file; the difference is renderer placement (in-feed) and is captured by the channel axis. (For non-video in-feed native units — title + image + body assembled by the renderer — use the dedicated `native_in_feed` canonical, which has a meaningfully different assembly shape.)
+
+Channels that DO need their own canonical (genuinely different shape, deferred):
+
+- **Audio dynamic ad insertion (DAI)** — ad-stitched audio with mid-stream insertion has a different tracking shape than `audio_hosted` or `audio_daast`. Likely a specialized canonical or `audio_daast` extension parameters when the pattern stabilizes.
+- **In-game** — playable / in-game ads have a SDK-specific composition model. Out of scope until cross-engine standards land.
+- **Live streaming** — live linear video (Twitch / YouTube Live / sports streaming with mid-roll) needs concurrent-impression and stream-state tracking. The `video_vast` canonical handles VAST-tag-driven live insertion today; richer live patterns deferred.
+
+**Rule of thumb (the "sibling refinement before canonical multiplication" principle).** Before reaching for a new canonical, check whether the difference is in (a) production model — covered by `asset_source`, (b) slot shape — covered by `slots_override`, (c) channel — covered by `applies_to_channels`, or (d) measurement / tracking — covered by `sync_event_sources` / `event_log`. New canonical only when the CREATIVE ASSET itself is structurally different (e.g., DAI's ad-stitched continuous audio stream is structurally different from `audio_hosted`'s file-per-impression). 50/50 ad formats in the v1 catalog now project to canonicals via this pattern; zero new canonicals were added for broadcast / DOOH / native / generative.
+
+### Generative-DSP and multi-output patterns are forward-looking
+
+The `asset_source` enums (including `seller_pre_rendered_from_brief` and `agent_synthesized`) and `item_production_model` on `sponsored_placement` are designed for generative-DSP and AI-rendered retail-media patterns that are emerging but not yet a large share of programmatic spend in 2026. Universalads-shaped tools, Pencil, AdCreative.ai, GenStudio-shaped tools — these are real adopters, but the volume is small relative to the boring 90% (buyer ships an MREC PNG; surface serves it). Reading too much into the schema breadth is a mistake. The fields exist so generative-DSP adopters have a clean v2 home; the worked examples include them so adopters can map their adapter cleanly. They are not a signal that the v2 narrative is AI-first. The dominant flows for 3.1 are still buyer-uploaded assets going through deterministic surfaces.
+
+### Creative-agent business model
+
+The third-party-creative-agent worked example assumes Flashtalking-shaped tools serve buyers via `build_creative` and let the buyer ship the produced manifest to the seller. Operators reading this should not infer that v2 strips creative agents of their hosting / serving / tracking revenue. Production happens at `build_creative`; the produced manifest can include hosted asset URLs on the creative agent's CDN (Flashtalking-hosted asset URLs in the example), and platform extensions can attach creative-agent-specific tracking (Flashtalking pixel IDs, viewability vendor configurations) that the seller honors at serve time. The v2 disaggregation is conceptual (the spec separates production from serving from tracking) — the operational integration path lets creative agents continue to host and instrument their produced creatives. v2 doesn't dictate where the asset bytes live or whose tracking JS runs; it only formalizes the production-vs-serving boundary that already exists implicitly.
+
+## Codegen vs runtime: the validator is the gate
+
+`product-format-declaration.json` carries an `allOf/if/then/else` that conditionally requires `format_shape`, `format_schema`, and `canonical_formats_only` only when `format_kind === "custom"`. The same pattern applies to `validate-input-result.json`'s `result_kind` discriminator with conditional `violations`. JSON Schema captures these conditionals cleanly, but most codegen pipelines (`json-schema-to-typescript`, `datamodel-codegen`) strip `if/then/else` before emitting types because conditional narrowing doesn't map to TypeScript's structural type system or to Pydantic's class model. The generated types are therefore strictly more permissive than the schema:
+
+- Generated TS / Python types accept a `format_kind: "custom"` declaration that omits `format_shape` or `format_schema` — the type system has no way to narrow on the discriminator and require the conditional fields.
+- The Ajv (or equivalent) runtime validator IS the gate. SDKs MUST run the JSON Schema validator before trusting a `ProductFormatDeclaration` parsed from the wire; the codegenned type is a convenience layer, not a contract.
+- Buyer-agent authors writing v2 in TypeScript SHOULD treat the generated types as a starting point and add their own runtime validation step — same pattern adopters already use for any JSON-Schema-validated API. Adopters who skip runtime validation will get type-system success on declarations that the schema rejects, and discover the gap only when their declarations hit a strict downstream validator.
+
+This is a doc concern, not a schema concern. The schema is more strict than the codegenned types; runtime validation closes the gap.
+
+## Migration
+
+| Adopter | Cost | Realistic timeline |
+|---|---|---|
+| DSP buyer agents | Low | 3.1-3.2 |
+| SSP/sales agents | Medium-high | 3.3-4.0 |
+| Walled gardens (Meta, Google, Amazon, TikTok, Snap, Pinterest) | High, low motivation | 4.0-5.0 if at all (gated on AAO providing a translator from existing format docs) |
+| Creative agents (AudioStack-shaped) | Low, high motivation | 3.1-3.2 |
+| Publisher direct (GAM/prebid path) | Medium | Blocked on native canonical pre-audit |
+
+**v1 stays first-class.** v1 named formats remain supported; sellers SHOULD provide server-side flatten wrappers that derive the v1 `list_creative_formats` shape from v2 product format declarations through 4.0. v2 is the *new* path, not the only path.
+
+### Realistic 3.1 coverage
+
+`v1-canonical-mapping.json` ships with ~15 unambiguous entries at 3.1 (IAB display sizes, VAST 4.x, DAAST 1.x). The full v1 audit catalogued 86 formats across 12 platforms; ~76% of those (≈65 formats) fit existing canonicals structurally but **only project automatically when either (a) the seller adds an explicit `canonical` field to their v1 format file, or (b) someone files a registry PR adding the `format_id_glob` or structural match.** Out of the gate at 3.1, 71+ of the audited formats are v1-only — they don't lose support, but a v2-only buyer agent doesn't see them on `format_options` until a seller or AAO contributor closes the gap. Through 3.x, expect most product traffic to remain v1 wire shape with opt-in `format_options` from early-adopter sellers (Meta, NYTimes, AudioStack, generative-DSP, retail-media). Buyer agents planning v2-only consumption in 3.x will see meaningfully thinner inventory than v1-aware agents; planning the codepath as dual-read through at least 3.3 is realistic. The 5.0 sunset for v1 is the floor on dual-emission, not the expected switchover date — anyone planning v2-only should pencil that in for 4.x at the earliest.
+
+## Phase status
+
+| Phase | Status | What's in it |
+|---|---|---|
+| Phase 1 | ✅ in #3307 | `asset_group_id` vocabulary registry (canonical entries + audit-grounded aliases), `video_brief` schema (renamed from earlier `scenes`), `zip` asset type, video/audio doc fixes |
+| Phase 2 | ✅ in #3307 | 12 canonical format definitions with structured `slots` declaration, `ProductFormatDeclaration` (format_kind discriminator + params), `validate_input` primitive, `creative.supported_formats` on get_adcp_capabilities, `brand_kit_override` inline on `BrandRef`, `platform-extension-ref`, typed inline `product_card` / `product_card_detailed`, `format_ids` + `format_options` `anyOf` on Product (dual emission legal during migration per #3765) |
+| Phase 3 | ✅ in #3307 | v1↔canonical-formats migration guide, 12 fully-validated reference Product fixtures + 1 get_products response fixture with bundled extensions, fixture-validation test suite (`npm run test:canonical-fixtures`) |
+| Phase 4 | ⚠️ MUST ship alongside 3.1.0 beta | Reference SDK codegen (TypeScript first, then Python), server-side flatten wrapper reference implementation, platform_extensions URI+digest fetch+cache helper, first-class typed accessors for `production_window_business_days` and other slot-level scheduling hints (otherwise adopters dig them out of the format blob and lose the v1↔v2 ergonomic win). Without Phase 4, adopters cannot consume canonical-formats cleanly — the typed-tagged-union ergonomics this PR's design earns require codegen to deliver. Without the flatten wrapper, walled gardens stay v1-only and `list_creative_formats` reality skews; with it, `format_ids` is auto-derived from `format_options` and migration is invisible to v1 consumers. **The schemas are shippable today; the SDK work is the gating dependency for adopter consumption and MUST land alongside the 3.1.0 beta, not after.** |
+
+## Empirical projection coverage
+
+The AAO catalog at `creative.adcontextprotocol.org` (the published v1 format library in `server/src/creative-agent/reference-formats.json`) has **33 of 57 entries** (58%) annotated with `canonical: <format_kind>` — direct v1→v2 projection, no SDK guesswork. The remaining 24 fall into deliberate gaps the spec is explicit about rather than coverage shortfalls:
+
+**Final 3.1 coverage: 50/50 ad formats in the v1 catalog are annotated**, via the projection-ref object form (`canonical: { kind, asset_source?, slots_override? }`). Plus 7 UI-scaffolding card entries (`product_card_*`, `format_card_*`, `proposal_card_*`, `native_product_card`) split into `server/src/creative-agent/ui-element-formats.json` since they're not ad formats — they're agent-interface display widgets that never project to ad canonicals.
+
+How each previously-unannotated group landed:
+
+- **8 generative entries** (`display_generative`, `display_300x250_generative`, `display_728x90_generative`, `display_320x50_generative`, `display_160x600_generative`, `display_336x280_generative`, `display_300x600_generative`, `display_970x250_generative`) — annotated as `{ kind: "image", asset_source: "agent_synthesized", slots_override: [{ generation_prompt: text, required }] }`. v2-aware buyers projecting see "this format wants a text prompt, not image bytes." Sibling refinement on `asset_source` + `slots_override`; no `image_generative` canonical needed.
+- **3 broadcast** (`broadcast_spot_15s/30s/60s`) — `{ kind: "video_hosted" }`. Sellers narrow via `applies_to_channels: ["tv"]` on the v2 product. Same asset shape (video file + duration + codec).
+- **4 DOOH** (`dooh_billboard_*`, `dooh_transit_screen`) — `{ kind: "image" }`. Sellers narrow via `applies_to_channels: ["dooh"]`. Location-keyed measurement differences live on `sync_event_sources`, not on the format.
+- **2 native** (`native_standard`, `native_content`) — `{ kind: "image", asset_source: "buyer_uploaded", slots_override: [...] }` with native-specific slots (icon, disclosure, sponsored_by).
+
+The SDK side's v1→v2 projection (validated in [adcp-client #1815](https://github.com/adcontextprotocol/adcp-client/pull/1815)) projects cleanly across all 50. Same architecture symmetry on v2→v1: clean projection plus honest fail-closed via `v1_translatable: false` / `canonical_formats_only: true` for canonicals the spec is explicit about not having v1 forms.
+
+**The "no new canonical" pattern (normative for future contributions).** Generative, broadcast, DOOH, and native all looked like they wanted new canonicals. None of them got one. The pattern: refine an existing canonical via `asset_source` + `slots_override` + `applies_to_channels`, route measurement/tracking differences to `sync_event_sources` / `event_log`, and only mint a new canonical when the CREATIVE ASSET itself is structurally different (which is rare). The "How does a seller say 'I don't do generative'?" question is settled by this principle — automatic, via the default `asset_source: buyer_uploaded` and required `image_main: image` slot.
+
+## Related
+
+- [v1 → canonical-formats migration guide](/docs/creative/canonical-formats-migration) — concrete migration paths for sellers, creative agents, buyers, and publisher-direct integrations
+- [RFC #3305](https://github.com/adcontextprotocol/adcp/issues/3305) — v2 architecture decisions and rationale
+- [PR #3307](https://github.com/adcontextprotocol/adcp/pull/3307) — Phase 1 + Phase 2 implementation, on hold pending 3.1.0 beta cycle
+- [Asset group vocabulary](https://adcontextprotocol.org/schemas/v3/core/asset-group-vocabulary.json) — canonical slot-name registry
+- [Video Brief schema](https://adcontextprotocol.org/schemas/v3/creative/video-brief.json) — typed per-segment generation brief for build_creative (renamed from earlier `scenes`)
+- [Universal macros](/docs/creative/universal-macros) — substitution patterns referenced from canonical tracking
diff --git a/docs/creative/channels/audio.mdx b/docs/creative/channels/audio.mdx
index 99cb9a0c9c..32ed56fdaa 100644
--- a/docs/creative/channels/audio.mdx
+++ b/docs/creative/channels/audio.mdx
@@ -197,9 +197,9 @@ Multi-segment audio assembled dynamically:
     "id": "audio_30s_vast"
   },
   "assets": {
-    "vast_url": {
-      "asset_type": "url",
-      "url_type": "tracker_pixel",
+    "vast_tag": {
+      "asset_type": "vast",
+      "delivery_type": "url",
       "url": "https://ad-server.brand.com/audio-vast?campaign={MEDIA_BUY_ID}&cb={CACHEBUSTER}"
     }
   }
diff --git a/docs/creative/channels/video.mdx b/docs/creative/channels/video.mdx
index d9af5b392d..a39730fb59 100644
--- a/docs/creative/channels/video.mdx
+++ b/docs/creative/channels/video.mdx
@@ -419,12 +419,11 @@ For third-party ad servers:
   "assets": [
     {
       "asset_id": "vast_tag",
-      "asset_type": "url",
-      "asset_role": "vast_url",
+      "asset_type": "vast",
       "item_type": "individual",
       "required": true,
       "requirements": {
-        "vast_version": ["3.0", "4.0", "4.1", "4.2"]
+        "vast_version": "4.2"
       }
     }
   ]
@@ -445,13 +444,13 @@ For third-party ad servers:
   "assets": [
     {
       "asset_id": "vpaid_tag",
-      "asset_type": "url",
-      "asset_role": "vpaid_url",
+      "asset_type": "vast",
       "item_type": "individual",
       "required": true,
       "requirements": {
         "vpaid_version": ["2.0"],
-        "api_framework": "VPAID"
+        "api_framework": "VPAID",
+        "vpaid_enabled": true
       }
     }
   ]
@@ -762,13 +761,13 @@ VPAID (Video Player Ad-Serving Interface Definition) enables interactive video a
   "assets": [
     {
       "asset_id": "vpaid_tag",
-      "asset_type": "url",
-      "asset_role": "vpaid_url",
+      "asset_type": "vast",
       "item_type": "individual",
       "required": true,
       "requirements": {
         "vpaid_version": ["2.0"],
-        "api_framework": "VPAID"
+        "api_framework": "VPAID",
+        "vpaid_enabled": true
       }
     }
   ]
diff --git a/docs/creative/formats.mdx b/docs/creative/formats.mdx
index 6b102b0a00..db85603889 100644
--- a/docs/creative/formats.mdx
+++ b/docs/creative/formats.mdx
@@ -4,6 +4,7 @@ description: "Creative formats in AdCP define asset requirements, technical cons
 "og:title": "AdCP — Creative Formats"
 ---
 
+> **Canonical-formats preview (3.1)**: starting in 3.1, formats can be declared inline on products via `format_options` (an array of `ProductFormatDeclaration`s narrowing one of 12 canonical formats). This page describes the v1 format-registry model, which remains a first-class path through 4.x. For the canonical-formats model, see [canonical-formats](/docs/creative/canonical-formats) and the [migration guide](/docs/creative/canonical-formats-migration).
 
 Creative formats define the structural and technical requirements used to instantiate advertising creatives. A format specifies:
 - The asset types required (video, image, text, audio, etc.) via the `assets` array
diff --git a/docs/creative/generative-creative.mdx b/docs/creative/generative-creative.mdx
index a2596e2914..cd68a04a7a 100644
--- a/docs/creative/generative-creative.mdx
+++ b/docs/creative/generative-creative.mdx
@@ -5,6 +5,8 @@ description: "Generative creative in AdCP uses AI to produce ad assets from a br
 "og:image": /images/walkthrough/diagram-generative-tiers.png
 ---
 
+> **Canonical-formats preview (3.1)**: in canonical formats, the "generative" category dissolves at the protocol level — production mechanism (generative AI, host recording, transcoding, asset rendering) is invisible to the buyer. Production source is declared per-canonical via `*_source` enums (`audio_source`, `image_source`, `video_source`, `item_production_model`); `synthesis_nondeterministic: true` flags Veo / Sora / Runway-class flows that need post-synthesis QA-loop semantics. See [canonical-formats](/docs/creative/canonical-formats) §"Two axes" for the canonical-formats model.
+
 The Creative Protocol enables AI-powered creative generation and asset management for advertising campaigns. This guide will help you create your first creative in 5 minutes.
 
 <img src="/images/walkthrough/diagram-generative-tiers.png" alt="Three tiers of generative creative: Tier 1 static (one creative, one variant), Tier 2 optimized (asset group combinations), Tier 3 generated (AI creates for each context)" style={{ width: '100%', borderRadius: '12px', marginBottom: '1.5rem' }} />
diff --git a/docs/creative/implementing-creative-agents.mdx b/docs/creative/implementing-creative-agents.mdx
index 8fe90ac72f..153ba140e9 100644
--- a/docs/creative/implementing-creative-agents.mdx
+++ b/docs/creative/implementing-creative-agents.mdx
@@ -4,6 +4,7 @@ description: "How to build an AdCP creative agent that defines formats, validate
 "og:title": "AdCP — Implementing Creative Agents"
 ---
 
+> **Canonical-formats preview (3.1)**: in the canonical-formats path, creative agents declare what they can produce via `creative.supported_formats` on `get_adcp_capabilities` (replacing the v1 `list_creative_formats` overload for creative agents). Each entry uses the same `ProductFormatDeclaration` shape as a product's inline `format_options[i]`. See [canonical-formats](/docs/creative/canonical-formats).
 
 This guide explains how to implement a creative agent that defines and manages creative formats.
 
diff --git a/docs/creative/key-concepts.mdx b/docs/creative/key-concepts.mdx
index 40c5071d6c..ec583ded86 100644
--- a/docs/creative/key-concepts.mdx
+++ b/docs/creative/key-concepts.mdx
@@ -4,6 +4,7 @@ description: "Assets, formats, manifests, and creative agents are the four build
 "og:title": "AdCP — Creative key concepts"
 ---
 
+> **Canonical-formats preview (3.1)**: this page describes the v1 model. For the canonical-formats architectural shift (inline `format_options` on products, production-source axis, `validate_input` primitive), see [canonical-formats](/docs/creative/canonical-formats).
 
 One upload, every format. This guide explains how creatives work in AdCP, from defining format requirements to assembling and delivering ads.
 
diff --git a/docs/creative/specification.mdx b/docs/creative/specification.mdx
index c428692f83..73a2e646cd 100644
--- a/docs/creative/specification.mdx
+++ b/docs/creative/specification.mdx
@@ -9,6 +9,8 @@ sidebarTitle: Specification
 **AdCP 3.0 Proposal** - This specification is under development for AdCP 3.0. Feedback welcome via [GitHub Discussions](https://github.com/adcontextprotocol/adcp/discussions).
 </Info>
 
+> **Canonical-formats preview (3.1)**: this page describes the v1 specification model. For the canonical-formats model (inline `format_options` on products, `validate_input` primitive), see [canonical-formats](/docs/creative/canonical-formats) and the [migration guide](/docs/creative/canonical-formats-migration).
+
 **Status**: Request for Comments
 **Last Updated**: March 2026
 
diff --git a/docs/media-buy/media-buys/optimization-reporting.mdx b/docs/media-buy/media-buys/optimization-reporting.mdx
index 64a20e6775..7452358289 100644
--- a/docs/media-buy/media-buys/optimization-reporting.mdx
+++ b/docs/media-buy/media-buys/optimization-reporting.mdx
@@ -896,7 +896,7 @@ Row-oriented format with embedded schema. Self-describing — readers don't need
 {
   "type": "record",
   "name": "MediaBuyDelivery",
-  "namespace": "org.adcp.reporting",
+  "namespace": "org.example.reporting",
   "fields": [
     {"name": "notification_type", "type": "string"},
     {"name": "sequence_number", "type": "int"},
diff --git a/docs/registry/index.mdx b/docs/registry/index.mdx
index a296209323..1b8d7a1e13 100644
--- a/docs/registry/index.mdx
+++ b/docs/registry/index.mdx
@@ -101,9 +101,9 @@ Three endpoints answer different questions about who is in the registry. They sp
 
 **`GET /api/registry/agents`** — the catalog of AAO-attested member-enrolled agents in the registry. Use this when you want to browse or filter the public agent population. See [Registering an agent](/docs/registry/registering-an-agent) for how agents end up in this catalog. Reference: [List agents endpoint](#agent-discovery) under Agent Discovery.
 
-**`GET /api/registry/operator?domain=X`** — given a domain, returns the agents that entity operates and the publishers that trust them. Use this when you have one entity in hand and want its agent footprint. Response shape is auth-aware: anonymous callers see only `public` agents, AAO API-tier callers also see `members_only`, and profile owners additionally see `private` (`server/src/routes/registry-api.ts:5486`). Reference: [Operator lookup](/docs/registry/api-reference/authorization-lookups/operator-lookup) under Authorization Lookups.
+**`GET /api/registry/operator?domain=X`** — given a domain, returns the agents that entity operates and the publishers that trust them. Use this when you have one entity in hand and want its agent footprint. Response shape is auth-aware: anonymous callers see only `public` agents, AAO API-tier callers also see `members_only`, and profile owners additionally see `private` (`server/src/routes/registry-api.ts:5486`). Reference handler: `server/src/routes/registry-api.ts:5486` (Operator lookup).
 
-**`GET /api/registry/publisher?domain=X`** — given a domain, returns the inventory that entity publishes (`properties[]`) and which agents it authorizes (`authorized_agents[]` from its `adagents.json`). Use this when you have one publisher in hand and want its inventory and delegations. The endpoint is unauthenticated and returns the same shape for every caller (`server/src/routes/registry-api.ts:5550`). Reference: [Publisher lookup](/docs/registry/api-reference/authorization-lookups/publisher-lookup) under Authorization Lookups.
+**`GET /api/registry/publisher?domain=X`** — given a domain, returns the inventory that entity publishes (`properties[]`) and which agents it authorizes (`authorized_agents[]` from its `adagents.json`). Use this when you have one publisher in hand and want its inventory and delegations. The endpoint is unauthenticated and returns the same shape for every caller (`server/src/routes/registry-api.ts:5550`). Reference handler: `server/src/routes/registry-api.ts:5550` (Publisher lookup).
 
 ### Brand Resolution
 
diff --git a/docs/registry/registering-an-agent.mdx b/docs/registry/registering-an-agent.mdx
index a2db07765d..cbe8a1b8c8 100644
--- a/docs/registry/registering-an-agent.mdx
+++ b/docs/registry/registering-an-agent.mdx
@@ -27,7 +27,7 @@ There is one path: **an AAO member adds the agent to their member profile** via
 
 **What this path attests:** the member has signed AAO terms; the URL, name, and contact are explicitly declared; the type is probe-verified. Visibility can be `public`, `members_only`, or `private` — see [Visibility](#visibility) below.
 
-There is no auto-population from crawled `adagents.json` files. Agents listed in third-party `adagents.json` files populate the publisher-authorization graph used by [Operator lookup](/docs/registry/api-reference/authorization-lookups/operator-lookup), `/api/registry/lookup/domain`, and `hasValidAdagents`, but they do not create catalog entries.
+There is no auto-population from crawled `adagents.json` files. Agents listed in third-party `adagents.json` files populate the publisher-authorization graph used by the Operator lookup endpoint (`GET /api/registry/operator?domain=X`), `/api/registry/lookup/domain`, and `hasValidAdagents`, but they do not create catalog entries.
 
 ## Programmatic registration (for CI, scripts, agents)
 
@@ -35,12 +35,12 @@ To register agents from CI, a deploy hook, or your own agent — without the das
 
 Authenticate with a WorkOS API key (`Authorization: Bearer sk_…`) or an OAuth user JWT. Mint an API key under [agenticadvertising.org/dashboard/api-keys](https://agenticadvertising.org/dashboard/api-keys).
 
-| Endpoint | Reference |
+| Endpoint | Purpose |
 |---|---|
-| `GET /api/me/agents` | [List my registered agents](/docs/registry/api-reference/member-agents/list-my-registered-agents) |
-| `POST /api/me/agents` | [Register an agent](/docs/registry/api-reference/member-agents/register-an-agent) |
-| `PATCH /api/me/agents/{url}` | [Update an agent](/docs/registry/api-reference/member-agents/update-an-agent) |
-| `DELETE /api/me/agents/{url}` | [Remove an agent](/docs/registry/api-reference/member-agents/remove-an-agent) |
+| `GET /api/me/agents` | List my registered agents |
+| `POST /api/me/agents` | Register an agent |
+| `PATCH /api/me/agents/{url}` | Update an agent |
+| `DELETE /api/me/agents/{url}` | Remove an agent |
 
 The path parameter on PATCH and DELETE is the agent's `url`, URL-encoded (e.g. `https%3A%2F%2Fagent.example.com%2Fmcp`). `POST` is idempotent on `url`: new entries return `201`; re-posting the same `url` updates the existing entry and returns `200`. Each successful write returns `{ agent, warnings? }` — `warnings` lists any tier-driven visibility downgrades (e.g. an Explorer-tier caller asking for `public` is stored as `members_only` with a `visibility_downgraded` warning).
 
@@ -110,6 +110,7 @@ To check whether your agent is referenced in a publisher's `adagents.json` (for
 
 ## Related
 
-- [Operator lookup](/docs/registry/api-reference/authorization-lookups/operator-lookup) — auth-aware per-entity view of agents and authorizations.
-- [List agents](/docs/registry/api-reference/agent-discovery/list-agents) — full registry catalog.
-- [Request domain re-crawl](/docs/registry/api-reference/agent-discovery/request-domain-re-crawl) — refresh a publisher's `adagents.json` mapping in the authorization graph.
+- [Registry overview](/docs/registry) — endpoint catalog, lookup flows, and brand resolution.
+- `GET /api/registry/operator?domain=X` — auth-aware per-entity view of agents and authorizations.
+- `GET /api/registry/agents` — full registry catalog.
+- `POST /api/registry/recrawl` — refresh a publisher's `adagents.json` mapping in the authorization graph.
diff --git a/package.json b/package.json
index 6f1d38f9e5..c1be263e47 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,9 @@
     "test:extension-schemas": "node tests/extension-schemas.test.cjs",
     "test:snippets": "node tests/snippet-validation.test.cjs",
     "test:json-schema": "node tests/json-schema-validation.test.cjs",
+    "test:canonical-fixtures": "node tests/canonical-fixture-validation.test.cjs",
+    "test:canonical-negative": "node tests/canonical-negative-fixtures.test.cjs",
+    "test:canonical-conventions": "node tests/canonical-format-conventions.test.cjs",
     "test:error-handling": "node tests/check-error-handling.cjs",
     "test:composed": "node tests/composed-schema-validation.test.cjs",
     "test:rejection-arm-mutex": "node tests/rejection-arm-mutual-exclusion.test.cjs",
diff --git a/scripts/error-code-drift-dispositions.json b/scripts/error-code-drift-dispositions.json
index 986ad48773..add64fba73 100644
--- a/scripts/error-code-drift-dispositions.json
+++ b/scripts/error-code-drift-dispositions.json
@@ -116,6 +116,41 @@
       "target_version": "3.1",
       "note": "Part of agent-permission-denied scope codes (#3887). Held for 3.1."
     },
+    "FORMAT_PROJECTION_FAILED": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "Canonical-formats v1→v2 projection advisory (#3307). Non-fatal; surfaces on get_products errors[] when an SDK can't project a v1 named format to a v2 canonical via the registry. Wire change — held for 3.1."
+    },
+    "FORMAT_DECLARATION_DIVERGENT": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "Canonical-formats dual-emission divergence advisory (#3307). Non-fatal; surfaces when a product carries both format_ids (v1) and format_options (v2) that disagree after projection. Wire change — held for 3.1."
+    },
+    "FORMAT_DECLARATION_V1_AMBIGUOUS": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "Canonical-formats v1-ambiguity advisory (#3307; adcp-client #1815). Non-fatal; surfaces when registry has only family-level structural entries for a canonical (no invertible literal) so SDK can't pick a specific v1 format_id mechanically. SDKs MUST NOT synthesize — seller MUST author v1_format_ref on the v2 declaration. Wire change — held for 3.1."
+    },
+    "FORMAT_CAPABILITY_UNRESOLVED": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "Canonical-formats capability-resolution advisory (#3307; #4620). Non-fatal; surfaces when a placement's `format_options[].capability_id` references a capability not declared in the file's top-level `formats[]`. Same-file scope only (cross-file lookup not supported by design). Wire change — held for 3.1."
+    },
+    "FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "Canonical-formats multi-size v1 emission advisory (#3307; adopter feedback from SDK implementor). Non-fatal; surfaces when a v2 declaration's `params.sizes[]` count exceeds its `v1_format_ref[]` count — v1 buyers see partial size coverage. Emitted alongside the partial v1 emit, not in place of it. SDK MAY (non-normative) fan out automatically via catalog lookup. Wire change — held for 3.1."
+    },
+    "PIXEL_TRACKER_LOSSY_DOWNGRADE": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "pixel_tracker → v1 url+tracker_pixel downgrade advisory (#3307; #4706). Non-fatal; surfaces when a 3.1 buyer SDK downgrades a pixel_tracker asset for a 3.0.x seller. URL still fires; lost fields (event variant, method:js execution context, or custom event timing) reported in error.details. Wire change — held for 3.1."
+    },
+    "PIXEL_TRACKER_UPGRADE_INFERRED": {
+      "disposition": "held-for-next-minor",
+      "target_version": "3.1",
+      "note": "v1 url+tracker_pixel → pixel_tracker upgrade-by-inference advisory (#3307; #4706). Non-fatal; surfaces when a 3.1 SDK upgrades a v1 tracker by inferring event and method from asset_id conventions. Wire change — held for 3.1."
+    },
     "UNSUPPORTED_GRANULARITY": {
       "disposition": "held-for-next-minor",
       "target_version": "3.1",
diff --git a/scripts/oneof-discriminators.baseline.json b/scripts/oneof-discriminators.baseline.json
index c533c47492..f51b442571 100644
--- a/scripts/oneof-discriminators.baseline.json
+++ b/scripts/oneof-discriminators.baseline.json
@@ -161,10 +161,30 @@
       "variants": 3,
       "note": "0:[travel_time,transport_mode] | 1:[radius] | 2:[geometry]"
     },
+    "core/creative-asset.json##/oneOf": {
+      "kind": "narrowable",
+      "variants": 2,
+      "note": "0:[format_id] | 1:[format_kind]"
+    },
+    "core/creative-asset.json##/properties/assets/patternProperties/^[a-z0-9_]+$/oneOf": {
+      "kind": "dangerous",
+      "variants": 2,
+      "note": "shared-required=[∅]; 0:nested-union(/schemas/core/assets/asset-union.json) | 1:array"
+    },
+    "core/creative-manifest.json##/oneOf": {
+      "kind": "narrowable",
+      "variants": 2,
+      "note": "0:[format_id] | 1:[format_kind]"
+    },
+    "core/creative-manifest.json##/properties/assets/patternProperties/^[a-z0-9_]+$/oneOf": {
+      "kind": "dangerous",
+      "variants": 2,
+      "note": "shared-required=[∅]; 0:nested-union(/schemas/core/assets/asset-union.json) | 1:array"
+    },
     "core/format.json##/properties/assets/items/oneOf": {
       "kind": "dangerous",
-      "variants": 15,
-      "note": "shared-required=[∅]; 0:req=[∅] | 1:req=[∅] | 2:req=[∅] | 3:req=[∅] | 4:req=[∅] | 5:req=[∅] | 6:req=[∅] | 7:req=[∅] | 8:req=[∅] | 9:req=[∅] | 10:req=[∅] | 11:req=[∅] | 12:req=[∅] | 13:req=[∅] | 14:req=[item_type,asset_group_id,required,min_count,max_count,assets]"
+      "variants": 16,
+      "note": "shared-required=[∅]; 0:req=[∅] | 1:req=[∅] | 2:req=[∅] | 3:req=[∅] | 4:req=[∅] | 5:req=[∅] | 6:req=[∅] | 7:req=[∅] | 8:req=[∅] | 9:req=[∅] | 10:req=[∅] | 11:req=[∅] | 12:req=[∅] | 13:req=[∅] | 14:req=[∅] | 15:req=[item_type,asset_group_id,required,min_count,max_count,assets]"
     },
     "core/format.json##/properties/renders/items/oneOf": {
       "kind": "narrowable",
@@ -196,6 +216,11 @@
       "variants": 2,
       "note": "0:[results] | 1:[errors]"
     },
+    "creative/list-creatives-response.json##/properties/creatives/items/properties/assets/patternProperties/^[a-z0-9_]+$/oneOf": {
+      "kind": "dangerous",
+      "variants": 2,
+      "note": "shared-required=[∅]; 0:nested-union(/schemas/core/assets/asset-union.json) | 1:array"
+    },
     "creative/preview-creative-response.json##/oneOf/1/properties/results/items/oneOf": {
       "kind": "narrowable",
       "variants": 2,
@@ -206,6 +231,21 @@
       "variants": 3,
       "note": "0:[creatives] | 1:[errors] | 2:[status,task_id]"
     },
+    "formats/canonical/display_tag.json##/allOf/1/oneOf": {
+      "kind": "dangerous",
+      "variants": 4,
+      "note": "shared-required=[∅]; 0:req=[width,height] | 1:req=[sizes] | 2:req=[∅] | 3:req=[∅]"
+    },
+    "formats/canonical/html5.json##/allOf/1/oneOf": {
+      "kind": "dangerous",
+      "variants": 4,
+      "note": "shared-required=[∅]; 0:req=[width,height] | 1:req=[sizes] | 2:req=[∅] | 3:req=[∅]"
+    },
+    "formats/canonical/image.json##/allOf/1/oneOf": {
+      "kind": "dangerous",
+      "variants": 4,
+      "note": "shared-required=[∅]; 0:req=[width,height] | 1:req=[sizes] | 2:req=[∅] | 3:req=[∅]"
+    },
     "governance/sync-plans-request.json##/properties/plans/items/properties/budget/oneOf": {
       "kind": "narrowable",
       "variants": 2,
@@ -286,6 +326,11 @@
       "variants": 2,
       "note": "shared-required=[∅]; 0:string | 1:ref-only(/schemas/core/property-id.json)"
     },
+    "registries/v1-canonical-mapping.json##/properties/mappings/items/properties/v1_pattern/oneOf": {
+      "kind": "narrowable",
+      "variants": 2,
+      "note": "0:[format_id_glob] | 1:[structural]"
+    },
     "signals/activate-signal-response.json##/oneOf": {
       "kind": "narrowable",
       "variants": 2,
diff --git a/server/src/creative-agent/reference-formats.json b/server/src/creative-agent/reference-formats.json
index a1812dcb7f..31672eb128 100644
--- a/server/src/creative-agent/reference-formats.json
+++ b/server/src/creative-agent/reference-formats.json
@@ -24,10 +24,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -61,7 +84,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -98,10 +132,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -141,7 +198,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -178,10 +246,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -221,7 +312,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -258,10 +360,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -301,7 +426,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -338,10 +474,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -381,7 +540,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -418,10 +588,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -461,7 +654,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -498,10 +702,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -541,7 +768,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -578,10 +816,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -621,7 +882,18 @@
           "description": "Text prompt describing the desired creative"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        {
+          "asset_group_id": "generation_prompt",
+          "asset_type": "text",
+          "required": true
+        }
+      ]
+    }
   },
   {
     "format_id": {
@@ -652,10 +924,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -687,7 +982,10 @@
           ]
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -718,10 +1016,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -753,7 +1074,10 @@
           ]
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -795,7 +1119,10 @@
         "required": true,
         "asset_type": "vast"
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_vast"
+    }
   },
   {
     "format_id": {
@@ -826,10 +1153,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -864,7 +1214,10 @@
           "description": "30-second video file"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -895,10 +1248,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -933,7 +1309,10 @@
           "description": "15-second video file"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -978,7 +1357,10 @@
           "description": "VAST 4.x compatible tag"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_vast"
+    }
   },
   {
     "format_id": {
@@ -1022,10 +1404,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1060,7 +1465,10 @@
           "description": "1920x1080 video file"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1104,10 +1512,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1142,7 +1573,10 @@
           "description": "1280x720 video file"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1186,10 +1620,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1224,7 +1681,10 @@
           "description": "1080x1920 vertical video file"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1268,10 +1728,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1306,7 +1789,10 @@
           "description": "1080x1080 square video file"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1336,10 +1822,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1374,7 +1883,10 @@
           "description": "30-second CTV-optimized video file (1920x1080 recommended)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1404,12 +1916,35 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
         }
-      }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
+        }
+      }
     ],
     "supported_macros": [
       "MEDIA_BUY_ID",
@@ -1442,7 +1977,10 @@
           "description": "30-second CTV-optimized video file (1920x1080 recommended)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1450,7 +1988,7 @@
       "id": "broadcast_spot_15s"
     },
     "name": "Broadcast TV Spot - 15 seconds",
-    "description": "15-second broadcast television spot. H.264 HD video file delivered directly to station — no VAST, no impression tracking, no clickthrough.",
+    "description": "15-second broadcast television spot. H.264 HD video file delivered directly to station \u2014 no VAST, no impression tracking, no clickthrough.",
     "type": "video",
     "assets": [
       {
@@ -1528,7 +2066,10 @@
           "description": "15-second broadcast spot file (1920x1080 HD)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1536,7 +2077,7 @@
       "id": "broadcast_spot_30s"
     },
     "name": "Broadcast TV Spot - 30 seconds",
-    "description": "30-second broadcast television spot. H.264 HD video file delivered directly to station — no VAST, no impression tracking, no clickthrough.",
+    "description": "30-second broadcast television spot. H.264 HD video file delivered directly to station \u2014 no VAST, no impression tracking, no clickthrough.",
     "type": "video",
     "assets": [
       {
@@ -1614,7 +2155,10 @@
           "description": "30-second broadcast spot file (1920x1080 HD)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1622,7 +2166,7 @@
       "id": "broadcast_spot_60s"
     },
     "name": "Broadcast TV Spot - 60 seconds",
-    "description": "60-second broadcast television spot. H.264 HD video file delivered directly to station — no VAST, no impression tracking, no clickthrough.",
+    "description": "60-second broadcast television spot. H.264 HD video file delivered directly to station \u2014 no VAST, no impression tracking, no clickthrough.",
     "type": "video",
     "assets": [
       {
@@ -1700,7 +2244,10 @@
           "description": "60-second broadcast spot file (1920x1080 HD)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "video_hosted"
+    }
   },
   {
     "format_id": {
@@ -1742,10 +2289,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1785,7 +2355,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -1840,10 +2413,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1886,7 +2482,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -1941,10 +2540,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -1987,7 +2609,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -2042,10 +2667,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2088,7 +2736,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -2143,10 +2794,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2189,7 +2863,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -2244,10 +2921,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2290,7 +2990,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -2345,10 +3048,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2391,7 +3117,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -2446,10 +3175,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2492,7 +3244,10 @@
           "description": "Clickthrough destination URL"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -2520,10 +3275,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2549,7 +3327,10 @@
           "max_file_size_mb": 0.5
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -2590,10 +3371,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2622,7 +3426,10 @@
           "description": "HTML5 creative code"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -2662,10 +3469,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2693,7 +3523,10 @@
           "max_file_size_mb": 0.5
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -2733,10 +3566,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2764,7 +3620,10 @@
           "max_file_size_mb": 0.5
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -2804,10 +3663,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2835,7 +3717,10 @@
           "max_file_size_mb": 0.5
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -2875,10 +3760,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2906,7 +3814,10 @@
           "max_file_size_mb": 0.5
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -2946,10 +3857,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -2977,7 +3911,10 @@
           "max_file_size_mb": 0.5
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "html5"
+    }
   },
   {
     "format_id": {
@@ -3001,10 +3938,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3026,7 +3986,10 @@
         "required": true,
         "asset_type": "javascript"
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "display_tag"
+    }
   },
   {
     "format_id": {
@@ -3095,10 +4058,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3159,7 +4145,48 @@
           "description": "Advertiser name for disclosure"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "slots_override": [
+        {
+          "asset_group_id": "image_main",
+          "asset_type": "image",
+          "required": true
+        },
+        {
+          "asset_group_id": "headline",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "body_text",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "cta",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "brand_name",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "impression_tracker",
+          "asset_type": "pixel_tracker",
+          "required": false
+        },
+        {
+          "asset_group_id": "click_tracker",
+          "asset_type": "pixel_tracker",
+          "required": false
+        }
+      ],
+      "asset_source": "buyer_uploaded"
+    }
   },
   {
     "format_id": {
@@ -3229,10 +4256,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3294,7 +4344,48 @@
           "description": "Sponsored content disclosure text"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image",
+      "slots_override": [
+        {
+          "asset_group_id": "image_main",
+          "asset_type": "image",
+          "required": true
+        },
+        {
+          "asset_group_id": "headline",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "body_text",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "landing_page_url",
+          "asset_type": "url",
+          "required": true
+        },
+        {
+          "asset_group_id": "disclosure",
+          "asset_type": "text",
+          "required": true
+        },
+        {
+          "asset_group_id": "impression_tracker",
+          "asset_type": "pixel_tracker",
+          "required": false
+        },
+        {
+          "asset_group_id": "click_tracker",
+          "asset_type": "pixel_tracker",
+          "required": false
+        }
+      ],
+      "asset_source": "buyer_uploaded"
+    }
   },
   {
     "format_id": {
@@ -3324,10 +4415,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3359,7 +4473,10 @@
           ]
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "audio_hosted"
+    }
   },
   {
     "format_id": {
@@ -3389,10 +4506,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3424,7 +4564,10 @@
           ]
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "audio_hosted"
+    }
   },
   {
     "format_id": {
@@ -3454,10 +4597,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3489,7 +4655,10 @@
           ]
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "audio_hosted"
+    }
   },
   {
     "format_id": {
@@ -3531,10 +4700,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3568,7 +4760,10 @@
           ]
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -3596,10 +4791,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3632,7 +4850,10 @@
           "description": "Landscape image (1920x1080 or larger)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -3660,10 +4881,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3696,7 +4940,10 @@
           "description": "Portrait image (1080x1920 or similar)"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
@@ -3739,10 +4986,33 @@
         "item_type": "individual",
         "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "url_type": "tracker_pixel",
           "description": "3rd party impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "viewability_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
+        "requirements": {
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_tracker",
+        "required": false,
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
+        "requirements": {
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3778,146 +5048,106 @@
           "description": "Transit screen content"
         }
       }
-    ]
+    ],
+    "canonical": {
+      "kind": "image"
+    }
   },
   {
     "format_id": {
       "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "product_card_standard"
+      "id": "sponsored_recommendation"
     },
-    "name": "Product Card - Standard",
-    "description": "Standard visual card (300x400px) for displaying ad inventory products",
-    "type": "display",
-    "renders": [
-      {
-        "dimensions": {
-          "height": 400,
-          "responsive": {
-            "height": false,
-            "width": false
-          },
-          "width": 300
-        },
-        "role": "primary"
-      }
-    ],
+    "name": "Sponsored Recommendation",
+    "description": "AI assistant sponsored recommendation woven into the conversation response. The LLM integrates the brand message naturally into its reply.",
+    "type": "native",
     "assets": [
       {
         "item_type": "individual",
-        "asset_id": "product_image",
-        "required": true,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Primary product image or placement preview"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "product_name",
+        "asset_id": "headline",
         "required": true,
         "asset_type": "text",
         "requirements": {
-          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
+          "description": "Short headline for the recommendation (50 chars max)"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "product_description",
+        "asset_id": "body",
         "required": true,
         "asset_type": "text",
         "requirements": {
-          "description": "Short description of the product (supports markdown)"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "pricing_model",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Pricing model (e.g., 'CPM', 'flat_rate', 'CPC')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "pricing_amount",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Price amount (e.g., '15.00')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "pricing_currency",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Currency code (e.g., 'USD')"
+          "description": "Body text describing the product or service. The AI assistant may paraphrase this to fit the conversation tone."
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "delivery_type",
+        "asset_id": "cta_text",
         "required": false,
         "asset_type": "text",
         "requirements": {
-          "description": "Delivery type: 'guaranteed' or 'bidded'"
+          "description": "Call-to-action text (e.g., 'Shop now', 'Learn more')"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "primary_asset_type",
-        "required": false,
-        "asset_type": "text",
+        "asset_id": "cta_url",
+        "required": true,
+        "asset_type": "url",
         "requirements": {
-          "description": "Primary asset type: 'display', 'video', 'audio', 'native'"
+          "url_type": "clickthrough",
+          "description": "Destination URL for the recommendation"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "publisher_name",
+        "asset_id": "image",
         "required": false,
-        "asset_type": "text",
+        "asset_type": "image",
         "requirements": {
-          "description": "Publisher or property name (e.g., 'Pinnacle News Group')"
+          "description": "Product or brand image (square, 400x400 recommended)"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "audience_summary",
-        "required": false,
+        "asset_id": "sponsored_by",
+        "required": true,
         "asset_type": "text",
         "requirements": {
-          "description": "Audience summary (e.g., 'Adults 25-54, 8M monthly uniques')"
+          "description": "Sponsor attribution text (e.g., 'Sponsored by Meridian Foods')"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "estimated_volume",
+        "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "text",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "description": "Estimated available impressions (e.g., '~2M impressions/month')"
-        }
+          "description": "Impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
       },
       {
         "item_type": "individual",
-        "asset_id": "click_url",
+        "asset_id": "viewability_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
         "requirements": {
-          "description": "Click-through URL for the product card (e.g., product detail page)"
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "impression_tracker",
+        "asset_id": "click_tracker",
         "required": false,
-        "asset_type": "url",
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
         "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "3rd party impression tracking pixel URL"
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -3925,843 +5155,80 @@
       "MEDIA_BUY_ID",
       "CREATIVE_ID",
       "CACHEBUSTER",
-      "CLICK_URL",
-      "DEVICE_TYPE",
-      "GDPR",
-      "GDPR_CONSENT",
-      "US_PRIVACY",
-      "GPP_STRING"
+      "CLICK_URL"
     ],
-    "assets_required": [
-      {
-        "asset_id": "product_image",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Primary product image or placement preview"
-        }
-      },
-      {
-        "asset_id": "product_name",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
-        }
-      },
-      {
-        "asset_id": "product_description",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Short description of the product (supports markdown)"
-        }
-      }
-    ]
+    "canonical": {
+      "kind": "sponsored_placement"
+    }
   },
   {
     "format_id": {
       "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "product_card_detailed"
+      "id": "native_mention"
     },
-    "name": "Product Card - Detailed",
-    "description": "Detailed card with carousel and full specifications for rich product presentation",
-    "type": "display",
-    "renders": [
-      {
-        "dimensions": {
-          "responsive": {
-            "height": true,
-            "width": true
-          }
-        },
-        "role": "primary"
-      }
-    ],
+    "name": "Native Brand Mention",
+    "description": "Minimal brand mention for AI assistants. A single line referencing the brand, suitable for light integration where a full product card would be intrusive.",
+    "type": "native",
     "assets": [
       {
         "item_type": "individual",
-        "asset_id": "product_image",
+        "asset_id": "mention_text",
         "required": true,
-        "asset_type": "image",
+        "asset_type": "text",
         "requirements": {
-          "description": "Primary product image or placement preview"
+          "description": "Brand mention text (100 chars max). Should read naturally in conversation context."
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "product_name",
+        "asset_id": "cta_url",
         "required": true,
-        "asset_type": "text",
+        "asset_type": "url",
         "requirements": {
-          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
+          "url_type": "clickthrough",
+          "description": "Destination URL if user clicks the mention"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "product_description",
+        "asset_id": "sponsored_by",
         "required": true,
         "asset_type": "text",
         "requirements": {
-          "description": "Detailed description of the product (supports markdown)"
+          "description": "Sponsor attribution text"
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "pricing_model",
+        "asset_id": "impression_tracker",
         "required": false,
-        "asset_type": "text",
+        "asset_type": "pixel_tracker",
         "requirements": {
-          "description": "Pricing model (e.g., 'CPM', 'flat_rate', 'CPC')"
-        }
+          "description": "Impression tracking pixel URL"
+        },
+        "event": "impression",
+        "method": "img"
       },
       {
         "item_type": "individual",
-        "asset_id": "pricing_amount",
+        "asset_id": "viewability_tracker",
         "required": false,
-        "asset_type": "text",
+        "asset_type": "pixel_tracker",
+        "event": "viewable_mrc_50",
+        "method": "img",
         "requirements": {
-          "description": "Price amount (e.g., '15.00')"
+          "description": "MRC 50% viewable tracker pixel (1-second viewability for display, 2-seconds with audio for video). Optional \u2014 measurement vendor URLs the seller's renderer fires when the viewable threshold is met."
         }
       },
       {
         "item_type": "individual",
-        "asset_id": "pricing_currency",
+        "asset_id": "click_tracker",
         "required": false,
-        "asset_type": "text",
+        "asset_type": "pixel_tracker",
+        "event": "click",
+        "method": "img",
         "requirements": {
-          "description": "Currency code (e.g., 'USD')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "delivery_type",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Delivery type: 'guaranteed' or 'bidded'"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "primary_asset_type",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Primary asset type: 'display', 'video', 'audio', 'native'"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "publisher_name",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Publisher or property name (e.g., 'Pinnacle News Group')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "audience_summary",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Audience summary (e.g., 'Adults 25-54, 8M monthly uniques')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "estimated_volume",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Estimated available impressions (e.g., '~2M impressions/month')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "click_url",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "description": "Click-through URL for the product card (e.g., product detail page)"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "impression_tracker",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "3rd party impression tracking pixel URL"
-        }
-      }
-    ],
-    "supported_macros": [
-      "MEDIA_BUY_ID",
-      "CREATIVE_ID",
-      "CACHEBUSTER",
-      "CLICK_URL",
-      "DEVICE_TYPE",
-      "GDPR",
-      "GDPR_CONSENT",
-      "US_PRIVACY",
-      "GPP_STRING"
-    ],
-    "assets_required": [
-      {
-        "asset_id": "product_image",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Primary product image or placement preview"
-        }
-      },
-      {
-        "asset_id": "product_name",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
-        }
-      },
-      {
-        "asset_id": "product_description",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Detailed description of the product (supports markdown)"
-        }
-      }
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "proposal_card_standard"
-    },
-    "name": "Proposal Card - Standard",
-    "description": "Standard visual card (300x400px) for displaying media plan proposals with allocation bars and budget guidance",
-    "type": "display",
-    "renders": [
-      {
-        "dimensions": {
-          "height": 400,
-          "responsive": {
-            "height": false,
-            "width": false
-          },
-          "width": 300
-        },
-        "role": "primary"
-      }
-    ],
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_name",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display name of the proposal"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_description",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Short description of the proposal"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "allocation_data",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "budget_min",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Minimum budget amount (e.g., '25000')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "budget_recommended",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Recommended budget amount (e.g., '75000')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "budget_currency",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Currency code (e.g., 'USD')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "brief_alignment",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Narrative explanation of how the proposal aligns with the brief"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_status",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Proposal status: 'draft' or 'committed'"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "publisher_name",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Publisher or network name (e.g., 'Pinnacle News Group')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "estimated_delivery",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Estimated delivery summary (e.g., 'Est. 3.2M impressions, 1.8M reach')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_image",
-        "required": false,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Hero image for the proposal card header"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "click_url",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "description": "Click-through URL for the proposal card (e.g., interactive proposal page)"
-        }
-      }
-    ],
-    "assets_required": [
-      {
-        "asset_id": "proposal_name",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display name of the proposal"
-        }
-      },
-      {
-        "asset_id": "proposal_description",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Short description of the proposal"
-        }
-      },
-      {
-        "asset_id": "allocation_data",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
-        }
-      }
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "proposal_card_detailed"
-    },
-    "name": "Proposal Card - Detailed",
-    "description": "Detailed card with full allocation breakdown, rationale, and budget for rich proposal presentation",
-    "type": "display",
-    "renders": [
-      {
-        "dimensions": {
-          "responsive": {
-            "height": true,
-            "width": true
-          }
-        },
-        "role": "primary"
-      }
-    ],
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_name",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display name of the proposal"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_description",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Detailed description of the proposal"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "allocation_data",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "budget_min",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Minimum budget amount (e.g., '25000')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "budget_recommended",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Recommended budget amount (e.g., '75000')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "budget_currency",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Currency code (e.g., 'USD')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "brief_alignment",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Narrative explanation of how the proposal aligns with the brief"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_status",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Proposal status: 'draft' or 'committed'"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "publisher_name",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Publisher or network name (e.g., 'Pinnacle News Group')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "estimated_delivery",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Estimated delivery summary (e.g., 'Est. 3.2M impressions, 1.8M reach')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "proposal_image",
-        "required": false,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Hero image for the proposal card header"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "click_url",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "description": "Click-through URL for the proposal card (e.g., interactive proposal page)"
-        }
-      }
-    ],
-    "assets_required": [
-      {
-        "asset_id": "proposal_name",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display name of the proposal"
-        }
-      },
-      {
-        "asset_id": "proposal_description",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Detailed description of the proposal"
-        }
-      },
-      {
-        "asset_id": "allocation_data",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
-        }
-      }
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "format_card_standard"
-    },
-    "name": "Format Card - Standard",
-    "description": "Standard visual card (300x400px) for displaying creative formats in user interfaces",
-    "type": "display",
-    "renders": [
-      {
-        "dimensions": {
-          "height": 400,
-          "responsive": {
-            "height": false,
-            "width": false
-          },
-          "width": 300
-        },
-        "role": "primary"
-      }
-    ],
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "format",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Creative format specification to visualize on the card"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "impression_tracker",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "3rd party impression tracking pixel URL"
-        }
-      }
-    ],
-    "supported_macros": [
-      "MEDIA_BUY_ID",
-      "CREATIVE_ID",
-      "CACHEBUSTER",
-      "CLICK_URL",
-      "DEVICE_TYPE",
-      "GDPR",
-      "GDPR_CONSENT",
-      "US_PRIVACY",
-      "GPP_STRING"
-    ],
-    "assets_required": [
-      {
-        "asset_id": "format",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Creative format specification to visualize on the card"
-        }
-      }
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "format_card_detailed"
-    },
-    "name": "Format Card - Detailed",
-    "description": "Detailed card with carousel and full specifications for rich format documentation",
-    "type": "display",
-    "renders": [
-      {
-        "dimensions": {
-          "responsive": {
-            "height": true,
-            "width": true
-          }
-        },
-        "role": "primary"
-      }
-    ],
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "format",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Creative format specification with full details for detailed card"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "impression_tracker",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "3rd party impression tracking pixel URL"
-        }
-      }
-    ],
-    "supported_macros": [
-      "MEDIA_BUY_ID",
-      "CREATIVE_ID",
-      "CACHEBUSTER",
-      "CLICK_URL",
-      "DEVICE_TYPE",
-      "GDPR",
-      "GDPR_CONSENT",
-      "US_PRIVACY",
-      "GPP_STRING"
-    ],
-    "assets_required": [
-      {
-        "asset_id": "format",
-        "item_type": "individual",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Creative format specification with full details for detailed card"
-        }
-      }
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "sponsored_recommendation"
-    },
-    "name": "Sponsored Recommendation",
-    "description": "AI assistant sponsored recommendation woven into the conversation response. The LLM integrates the brand message naturally into its reply.",
-    "type": "native",
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "headline",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Short headline for the recommendation (50 chars max)"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "body",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Body text describing the product or service. The AI assistant may paraphrase this to fit the conversation tone."
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "cta_text",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Call-to-action text (e.g., 'Shop now', 'Learn more')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "cta_url",
-        "required": true,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "clickthrough",
-          "description": "Destination URL for the recommendation"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "image",
-        "required": false,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Product or brand image (square, 400x400 recommended)"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "sponsored_by",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Sponsor attribution text (e.g., 'Sponsored by Meridian Foods')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "impression_tracker",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "Impression tracking pixel URL"
-        }
-      }
-    ],
-    "supported_macros": [
-      "MEDIA_BUY_ID",
-      "CREATIVE_ID",
-      "CACHEBUSTER",
-      "CLICK_URL"
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "native_product_card"
-    },
-    "name": "Native Product Card",
-    "description": "Product card for AI assistants and retail media surfaces. Displays a product with image, price, and catalog items. Rendered as a card within the conversation or search results.",
-    "type": "native",
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "headline",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Product or offer headline (60 chars max)"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "body",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Product description or promotional text"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "image",
-        "required": true,
-        "asset_type": "image",
-        "requirements": {
-          "description": "Product image (square, 800x800 recommended)"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "price",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Display price (e.g., '$24.99', 'From $12/mo')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "cta_text",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Call-to-action text"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "cta_url",
-        "required": true,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "clickthrough",
-          "description": "Product page URL"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "sponsored_by",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Sponsor attribution text"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "badge",
-        "required": false,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Promotional badge (e.g., 'SALE', 'NEW', 'BEST SELLER')"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "impression_tracker",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "Impression tracking pixel URL"
+          "description": "Click measurement tracker pixel (distinct from landing_page_url, the destination). Optional \u2014 measurement vendor URL fired when the user clicks the creative, in addition to navigating to landing_page_url."
         }
       }
     ],
@@ -4771,69 +5238,8 @@
       "CACHEBUSTER",
       "CLICK_URL"
     ],
-    "catalog_requirements": [
-      {
-        "catalog_type": "product",
-        "required": false,
-        "required_fields": [
-          "name"
-        ]
-      }
-    ]
-  },
-  {
-    "format_id": {
-      "agent_url": "https://creative.adcontextprotocol.org/",
-      "id": "native_mention"
-    },
-    "name": "Native Brand Mention",
-    "description": "Minimal brand mention for AI assistants. A single line referencing the brand, suitable for light integration where a full product card would be intrusive.",
-    "type": "native",
-    "assets": [
-      {
-        "item_type": "individual",
-        "asset_id": "mention_text",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Brand mention text (100 chars max). Should read naturally in conversation context."
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "cta_url",
-        "required": true,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "clickthrough",
-          "description": "Destination URL if user clicks the mention"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "sponsored_by",
-        "required": true,
-        "asset_type": "text",
-        "requirements": {
-          "description": "Sponsor attribution text"
-        }
-      },
-      {
-        "item_type": "individual",
-        "asset_id": "impression_tracker",
-        "required": false,
-        "asset_type": "url",
-        "requirements": {
-          "url_type": "tracker_pixel",
-          "description": "Impression tracking pixel URL"
-        }
-      }
-    ],
-    "supported_macros": [
-      "MEDIA_BUY_ID",
-      "CREATIVE_ID",
-      "CACHEBUSTER",
-      "CLICK_URL"
-    ]
+    "canonical": {
+      "kind": "agent_placement"
+    }
   }
 ]
diff --git a/server/src/creative-agent/task-handlers.ts b/server/src/creative-agent/task-handlers.ts
index 29501f1e45..7007037602 100644
--- a/server/src/creative-agent/task-handlers.ts
+++ b/server/src/creative-agent/task-handlers.ts
@@ -21,6 +21,7 @@ import { storePreview } from './preview-store.js';
 
 const require = createRequire(import.meta.url);
 const referenceFormatsData = require('./reference-formats.json');
+const uiElementFormatsData = require('./ui-element-formats.json');
 
 // ── Types ───────────────────────────────────────────────────────────
 
@@ -36,9 +37,17 @@ const MAX_BATCH_SIZE = 20;
 /**
  * Build formats with agent_url rewritten to the local endpoint.
  * Source data is the exact format catalog from the live creative.adcontextprotocol.org agent.
+ * Unions reference-formats (50 ad formats with canonical: {kind,...} annotations) with
+ * ui-element-formats (7 card scaffolding formats used by training-agent + preview-renderer).
+ * Cards are emitted in list_creative_formats so consumers (training-agent product-factory,
+ * preview-renderer) can resolve them by format_id; they are NOT ad formats and never project
+ * to ad canonicals.
  */
 export function buildReferenceFormats(agentUrl: string): Format[] {
-  const formats = structuredClone(referenceFormatsData) as Format[];
+  const formats = [
+    ...structuredClone(referenceFormatsData) as Format[],
+    ...structuredClone(uiElementFormatsData) as Format[],
+  ];
   for (const f of formats) {
     const fid = f.format_id as { agent_url: string; id: string };
     fid.agent_url = agentUrl;
diff --git a/server/src/creative-agent/ui-element-formats.json b/server/src/creative-agent/ui-element-formats.json
new file mode 100644
index 0000000000..5dbee8442b
--- /dev/null
+++ b/server/src/creative-agent/ui-element-formats.json
@@ -0,0 +1,921 @@
+[
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "product_card_standard"
+    },
+    "name": "Product Card - Standard",
+    "description": "Standard visual card (300x400px) for displaying ad inventory products",
+    "type": "display",
+    "renders": [
+      {
+        "dimensions": {
+          "height": 400,
+          "responsive": {
+            "height": false,
+            "width": false
+          },
+          "width": 300
+        },
+        "role": "primary"
+      }
+    ],
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "product_image",
+        "required": true,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Primary product image or placement preview"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "product_name",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "product_description",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Short description of the product (supports markdown)"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "pricing_model",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Pricing model (e.g., 'CPM', 'flat_rate', 'CPC')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "pricing_amount",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Price amount (e.g., '15.00')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "pricing_currency",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Currency code (e.g., 'USD')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "delivery_type",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Delivery type: 'guaranteed' or 'bidded'"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "primary_asset_type",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Primary asset type: 'display', 'video', 'audio', 'native'"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "publisher_name",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Publisher or property name (e.g., 'Pinnacle News Group')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "audience_summary",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Audience summary (e.g., 'Adults 25-54, 8M monthly uniques')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "estimated_volume",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Estimated available impressions (e.g., '~2M impressions/month')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_url",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "description": "Click-through URL for the product card (e.g., product detail page)"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "impression_tracker",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "url_type": "tracker_pixel",
+          "description": "3rd party impression tracking pixel URL"
+        }
+      }
+    ],
+    "supported_macros": [
+      "MEDIA_BUY_ID",
+      "CREATIVE_ID",
+      "CACHEBUSTER",
+      "CLICK_URL",
+      "DEVICE_TYPE",
+      "GDPR",
+      "GDPR_CONSENT",
+      "US_PRIVACY",
+      "GPP_STRING"
+    ],
+    "assets_required": [
+      {
+        "asset_id": "product_image",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Primary product image or placement preview"
+        }
+      },
+      {
+        "asset_id": "product_name",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
+        }
+      },
+      {
+        "asset_id": "product_description",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Short description of the product (supports markdown)"
+        }
+      }
+    ]
+  },
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "product_card_detailed"
+    },
+    "name": "Product Card - Detailed",
+    "description": "Detailed card with carousel and full specifications for rich product presentation",
+    "type": "display",
+    "renders": [
+      {
+        "dimensions": {
+          "responsive": {
+            "height": true,
+            "width": true
+          }
+        },
+        "role": "primary"
+      }
+    ],
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "product_image",
+        "required": true,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Primary product image or placement preview"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "product_name",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "product_description",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Detailed description of the product (supports markdown)"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "pricing_model",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Pricing model (e.g., 'CPM', 'flat_rate', 'CPC')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "pricing_amount",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Price amount (e.g., '15.00')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "pricing_currency",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Currency code (e.g., 'USD')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "delivery_type",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Delivery type: 'guaranteed' or 'bidded'"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "primary_asset_type",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Primary asset type: 'display', 'video', 'audio', 'native'"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "publisher_name",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Publisher or property name (e.g., 'Pinnacle News Group')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "audience_summary",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Audience summary (e.g., 'Adults 25-54, 8M monthly uniques')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "estimated_volume",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Estimated available impressions (e.g., '~2M impressions/month')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_url",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "description": "Click-through URL for the product card (e.g., product detail page)"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "impression_tracker",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "url_type": "tracker_pixel",
+          "description": "3rd party impression tracking pixel URL"
+        }
+      }
+    ],
+    "supported_macros": [
+      "MEDIA_BUY_ID",
+      "CREATIVE_ID",
+      "CACHEBUSTER",
+      "CLICK_URL",
+      "DEVICE_TYPE",
+      "GDPR",
+      "GDPR_CONSENT",
+      "US_PRIVACY",
+      "GPP_STRING"
+    ],
+    "assets_required": [
+      {
+        "asset_id": "product_image",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Primary product image or placement preview"
+        }
+      },
+      {
+        "asset_id": "product_name",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the product (e.g., 'Homepage Leaderboard')"
+        }
+      },
+      {
+        "asset_id": "product_description",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Detailed description of the product (supports markdown)"
+        }
+      }
+    ]
+  },
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "proposal_card_standard"
+    },
+    "name": "Proposal Card - Standard",
+    "description": "Standard visual card (300x400px) for displaying media plan proposals with allocation bars and budget guidance",
+    "type": "display",
+    "renders": [
+      {
+        "dimensions": {
+          "height": 400,
+          "responsive": {
+            "height": false,
+            "width": false
+          },
+          "width": 300
+        },
+        "role": "primary"
+      }
+    ],
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_name",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the proposal"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_description",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Short description of the proposal"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "allocation_data",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "budget_min",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Minimum budget amount (e.g., '25000')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "budget_recommended",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Recommended budget amount (e.g., '75000')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "budget_currency",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Currency code (e.g., 'USD')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "brief_alignment",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Narrative explanation of how the proposal aligns with the brief"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_status",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Proposal status: 'draft' or 'committed'"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "publisher_name",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Publisher or network name (e.g., 'Pinnacle News Group')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "estimated_delivery",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Estimated delivery summary (e.g., 'Est. 3.2M impressions, 1.8M reach')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_image",
+        "required": false,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Hero image for the proposal card header"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_url",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "description": "Click-through URL for the proposal card (e.g., interactive proposal page)"
+        }
+      }
+    ],
+    "assets_required": [
+      {
+        "asset_id": "proposal_name",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the proposal"
+        }
+      },
+      {
+        "asset_id": "proposal_description",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Short description of the proposal"
+        }
+      },
+      {
+        "asset_id": "allocation_data",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
+        }
+      }
+    ]
+  },
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "proposal_card_detailed"
+    },
+    "name": "Proposal Card - Detailed",
+    "description": "Detailed card with full allocation breakdown, rationale, and budget for rich proposal presentation",
+    "type": "display",
+    "renders": [
+      {
+        "dimensions": {
+          "responsive": {
+            "height": true,
+            "width": true
+          }
+        },
+        "role": "primary"
+      }
+    ],
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_name",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the proposal"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_description",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Detailed description of the proposal"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "allocation_data",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "budget_min",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Minimum budget amount (e.g., '25000')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "budget_recommended",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Recommended budget amount (e.g., '75000')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "budget_currency",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Currency code (e.g., 'USD')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "brief_alignment",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Narrative explanation of how the proposal aligns with the brief"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_status",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Proposal status: 'draft' or 'committed'"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "publisher_name",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Publisher or network name (e.g., 'Pinnacle News Group')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "estimated_delivery",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Estimated delivery summary (e.g., 'Est. 3.2M impressions, 1.8M reach')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "proposal_image",
+        "required": false,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Hero image for the proposal card header"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "click_url",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "description": "Click-through URL for the proposal card (e.g., interactive proposal page)"
+        }
+      }
+    ],
+    "assets_required": [
+      {
+        "asset_id": "proposal_name",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display name of the proposal"
+        }
+      },
+      {
+        "asset_id": "proposal_description",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Detailed description of the proposal"
+        }
+      },
+      {
+        "asset_id": "allocation_data",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "JSON array of allocations: [{product_id, allocation_percentage, rationale}]"
+        }
+      }
+    ]
+  },
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "format_card_standard"
+    },
+    "name": "Format Card - Standard",
+    "description": "Standard visual card (300x400px) for displaying creative formats in user interfaces",
+    "type": "display",
+    "renders": [
+      {
+        "dimensions": {
+          "height": 400,
+          "responsive": {
+            "height": false,
+            "width": false
+          },
+          "width": 300
+        },
+        "role": "primary"
+      }
+    ],
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "format",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Creative format specification to visualize on the card"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "impression_tracker",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "url_type": "tracker_pixel",
+          "description": "3rd party impression tracking pixel URL"
+        }
+      }
+    ],
+    "supported_macros": [
+      "MEDIA_BUY_ID",
+      "CREATIVE_ID",
+      "CACHEBUSTER",
+      "CLICK_URL",
+      "DEVICE_TYPE",
+      "GDPR",
+      "GDPR_CONSENT",
+      "US_PRIVACY",
+      "GPP_STRING"
+    ],
+    "assets_required": [
+      {
+        "asset_id": "format",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Creative format specification to visualize on the card"
+        }
+      }
+    ]
+  },
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "format_card_detailed"
+    },
+    "name": "Format Card - Detailed",
+    "description": "Detailed card with carousel and full specifications for rich format documentation",
+    "type": "display",
+    "renders": [
+      {
+        "dimensions": {
+          "responsive": {
+            "height": true,
+            "width": true
+          }
+        },
+        "role": "primary"
+      }
+    ],
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "format",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Creative format specification with full details for detailed card"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "impression_tracker",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "url_type": "tracker_pixel",
+          "description": "3rd party impression tracking pixel URL"
+        }
+      }
+    ],
+    "supported_macros": [
+      "MEDIA_BUY_ID",
+      "CREATIVE_ID",
+      "CACHEBUSTER",
+      "CLICK_URL",
+      "DEVICE_TYPE",
+      "GDPR",
+      "GDPR_CONSENT",
+      "US_PRIVACY",
+      "GPP_STRING"
+    ],
+    "assets_required": [
+      {
+        "asset_id": "format",
+        "item_type": "individual",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Creative format specification with full details for detailed card"
+        }
+      }
+    ]
+  },
+  {
+    "format_id": {
+      "agent_url": "https://creative.adcontextprotocol.org/",
+      "id": "native_product_card"
+    },
+    "name": "Native Product Card",
+    "description": "Product card for AI assistants and retail media surfaces. Displays a product with image, price, and catalog items. Rendered as a card within the conversation or search results.",
+    "type": "native",
+    "assets": [
+      {
+        "item_type": "individual",
+        "asset_id": "headline",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Product or offer headline (60 chars max)"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "body",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Product description or promotional text"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "image",
+        "required": true,
+        "asset_type": "image",
+        "requirements": {
+          "description": "Product image (square, 800x800 recommended)"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "price",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Display price (e.g., '$24.99', 'From $12/mo')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "cta_text",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Call-to-action text"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "cta_url",
+        "required": true,
+        "asset_type": "url",
+        "requirements": {
+          "url_type": "clickthrough",
+          "description": "Product page URL"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "sponsored_by",
+        "required": true,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Sponsor attribution text"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "badge",
+        "required": false,
+        "asset_type": "text",
+        "requirements": {
+          "description": "Promotional badge (e.g., 'SALE', 'NEW', 'BEST SELLER')"
+        }
+      },
+      {
+        "item_type": "individual",
+        "asset_id": "impression_tracker",
+        "required": false,
+        "asset_type": "url",
+        "requirements": {
+          "url_type": "tracker_pixel",
+          "description": "Impression tracking pixel URL"
+        }
+      }
+    ],
+    "supported_macros": [
+      "MEDIA_BUY_ID",
+      "CREATIVE_ID",
+      "CACHEBUSTER",
+      "CLICK_URL"
+    ],
+    "catalog_requirements": [
+      {
+        "catalog_type": "product",
+        "required": false,
+        "required_fields": [
+          "name"
+        ]
+      }
+    ]
+  }
+]
diff --git a/skills/adcp-creative/SKILL.md b/skills/adcp-creative/SKILL.md
index 59d7077487..5bc0d7033e 100644
--- a/skills/adcp-creative/SKILL.md
+++ b/skills/adcp-creative/SKILL.md
@@ -29,6 +29,36 @@ The Creative Protocol provides 4 standardized tasks for building and previewing
 
 ---
 
+## Canonical formats (AdCP 3.1+)
+
+Products and manifests use the **canonical-formats** vocabulary — 11 canonical `format_kind` values that name the underlying creative shape (image / html5 / display_tag / video_hosted / video_vast / audio_hosted / audio_daast / image_carousel / responsive_creative / sponsored_placement / agent_placement / custom).
+
+A `ProductFormatDeclaration` carries:
+
+- `format_kind`: the canonical (discriminator)
+- `params`: per-canonical parameters narrowing the format (dimensions, durations, codecs, char limits, CTA enums, sizes[], etc.)
+- Optional `capability_id`: stable identifier for routing when a product carries multiple declarations of the same kind
+- Optional `v1_format_ref: [{agent_url, id}]`: **always an array** — links this v2 declaration to one or more v1 named formats. Multi-size declarations should carry one ref per size in `sizes[]`.
+- Optional `seller_preference: "preferred" | "accepted" | "discouraged"`: soft routing hint when a product carries multiple format_options
+
+**Where to declare a format:**
+
+| Where | When to use |
+|---|---|
+| `adagents.json` top-level `formats[]` (publisher catalog) | Format shared across many sellers of the same publisher inventory; declares the publisher-authoritative shape once |
+| `Product.format_options[]` (inline on a product) | Seller-specific narrowing, custom format, or one-off pricing variant. Reference a publisher catalog entry by `capability_id` when applicable |
+| `Placement.format_options[]` (capability_id reference OR inline) | Tying a publisher placement to one or more accepted formats |
+
+**Size flexibility (image / html5 / display_tag):** exactly one of three modes — `width`+`height` (fixed), `sizes: [{w,h}]` (multi-size, mirrors OpenRTB `banner.format[]`), or `min_width`/`max_width`/`min_height`/`max_height` (responsive).
+
+**Community mirror for unadopted platforms:** the AAO publishes adagents.json files for unadopted platforms (Meta, TikTok, etc.) at `https://creative.adcontextprotocol.org/translated/<platform>/adagents.json`. When the request asks "what formats does meta.com support?" the SDK fetches the platform's hosted file first, falls back to the AAO mirror, and surfaces which tier produced the result via the response's `source` field.
+
+**Conversion tracking is NOT a creative-format concern.** Pixel-firing, conversion events, and attribution belong on `sync_event_sources` / `event_log` (campaign-scoped). Don't stuff `pixel_id` into `platform_extensions` on a format declaration.
+
+See `docs/creative/canonical-formats.mdx` for the full vocabulary, narrowing rules, error-code surface, and worked examples (Meta Reels, IAB display, host-read podcast, generative DSP).
+
+---
+
 ## Task Reference
 
 ### list_creative_formats
diff --git a/skills/adcp-media-buy/SKILL.md b/skills/adcp-media-buy/SKILL.md
index 2e3c93c6ed..cd90a5ccc6 100644
--- a/skills/adcp-media-buy/SKILL.md
+++ b/skills/adcp-media-buy/SKILL.md
@@ -37,6 +37,30 @@ The Media Buy Protocol provides 11 standardized tasks for managing advertising c
 
 ---
 
+## Canonical formats (AdCP 3.1+)
+
+Products carry `format_options[]`: a list of `ProductFormatDeclaration` entries describing the creative shapes the product accepts. Each declaration carries:
+
+- `format_kind` — canonical type (image / html5 / display_tag / video_hosted / video_vast / audio_hosted / audio_daast / image_carousel / responsive_creative / sponsored_placement / agent_placement / custom)
+- `params` — per-canonical parameters narrowing the format (dimensions, durations, codecs, char limits, CTA enums)
+- Optional `capability_id` — disambiguates when a product carries multiple declarations of the same `format_kind`, and lets a placement reference a publisher-catalog declaration by ID rather than inlining
+- Optional `v1_format_ref: [{agent_url, id}]` — array linking this v2 declaration to one or more v1 named formats (for dual emission during the v1↔v2 migration). Multi-size declarations should carry one ref per size
+- Optional `seller_preference: "preferred" | "accepted" | "discouraged"` — soft routing hint when a multi-format product has several options at the same price
+
+**Multi-format products.** A flexible publisher slot is one product with N format_options entries — e.g., NYTimes Homepage accepts image OR html5 OR display_tag at multiple sizes via three format_options, one per type. Buyer picks the creative type they ship.
+
+**Size flexibility.** Display canonicals (image / html5 / display_tag) declare size in one of three modes: fixed (`width`+`height`), multi-size (`sizes: [{w,h}]` — mirrors OpenRTB `banner.format[]`), or responsive (`min_width`/`max_width`/`min_height`/`max_height`). Modes are mutually exclusive.
+
+**Discovering publisher catalogs.** `list_creative_formats(publisher_domain="meta.com")` returns the publisher's authoritative format list by reading `<publisher_domain>/.well-known/adagents.json` `formats[]`, falling back to the AAO community mirror at `https://creative.adcontextprotocol.org/translated/<platform>/adagents.json`, then to agent-derived from own products. Response carries `source: "publisher" | "aao_mirror" | "agent_derived"` so buyers know which tier produced the list.
+
+**Conversion tracking lives elsewhere.** Pixel-firing, conversion events, and attribution belong on `sync_event_sources` / `event_log` (campaign-scoped), NOT on creative format declarations. Sending `pixel_id` in `platform_extensions` on a format is a category error.
+
+**Error codes specific to canonical formats.** `FORMAT_PROJECTION_FAILED`, `FORMAT_DECLARATION_DIVERGENT`, `FORMAT_DECLARATION_V1_AMBIGUOUS`, `FORMAT_CAPABILITY_UNRESOLVED`, `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` — all non-fatal advisories surfaced via the response `errors[]` array. See `static/schemas/source/enums/error-code.json` for full recovery semantics.
+
+See `docs/creative/canonical-formats.mdx` for the full vocabulary, narrowing rules, and worked examples.
+
+---
+
 ## Task Reference
 
 ### get_products
diff --git a/static/examples/adagents/community/meta.json b/static/examples/adagents/community/meta.json
new file mode 100644
index 0000000000..972d658f44
--- /dev/null
+++ b/static/examples/adagents/community/meta.json
@@ -0,0 +1,363 @@
+{
+  "$schema": "/schemas/adagents.json",
+  "contact": {
+    "name": "AdCP Community Registry \u2014 Meta translation",
+    "email": "registry@adcontextprotocol.org",
+    "domain": "adcontextprotocol.org"
+  },
+  "properties": [
+    {
+      "property_id": "instagram",
+      "property_type": "mobile_app",
+      "name": "Instagram",
+      "identifiers": [
+        {
+          "type": "ios_bundle",
+          "value": "com.burbn.instagram"
+        },
+        {
+          "type": "android_package",
+          "value": "com.instagram.android"
+        },
+        {
+          "type": "domain",
+          "value": "instagram.com"
+        }
+      ],
+      "tags": [
+        "meta_network",
+        "social_media"
+      ],
+      "supported_channels": [
+        "social",
+        "display",
+        "olv"
+      ],
+      "publisher_domain": "instagram.com"
+    },
+    {
+      "property_id": "facebook",
+      "property_type": "mobile_app",
+      "name": "Facebook",
+      "identifiers": [
+        {
+          "type": "ios_bundle",
+          "value": "com.facebook.Facebook"
+        },
+        {
+          "type": "android_package",
+          "value": "com.facebook.katana"
+        },
+        {
+          "type": "domain",
+          "value": "facebook.com"
+        }
+      ],
+      "tags": [
+        "meta_network",
+        "social_media"
+      ],
+      "supported_channels": [
+        "social",
+        "display",
+        "olv"
+      ],
+      "publisher_domain": "facebook.com"
+    },
+    {
+      "property_id": "whatsapp",
+      "property_type": "mobile_app",
+      "name": "WhatsApp",
+      "identifiers": [
+        {
+          "type": "ios_bundle",
+          "value": "net.whatsapp.WhatsApp"
+        },
+        {
+          "type": "android_package",
+          "value": "com.whatsapp"
+        }
+      ],
+      "tags": [
+        "meta_network",
+        "messaging"
+      ],
+      "supported_channels": [
+        "social",
+        "display"
+      ],
+      "publisher_domain": "whatsapp.com"
+    }
+  ],
+  "tags": {
+    "meta_network": {
+      "name": "Meta Network",
+      "description": "All Meta-owned properties"
+    },
+    "social_media": {
+      "name": "Social Media Apps",
+      "description": "Social networking applications"
+    },
+    "messaging": {
+      "name": "Messaging Apps",
+      "description": "Messaging and communication apps"
+    }
+  },
+  "formats": [
+    {
+      "capability_id": "meta_reels",
+      "display_name": "Meta Reels (Instagram + Facebook)",
+      "format_kind": "video_hosted",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/translated/meta",
+          "id": "meta_reels"
+        }
+      ],
+      "applies_to_property_ids": [
+        "instagram",
+        "facebook"
+      ],
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_range": [
+          3000,
+          90000
+        ],
+        "min_width": 1080,
+        "min_height": 1920,
+        "max_file_size_mb": 200,
+        "video_codecs": [
+          "h264"
+        ],
+        "audio_codecs": [
+          "aac"
+        ],
+        "containers": [
+          "mp4"
+        ],
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125,
+        "captions": "recommended",
+        "cta_values": [
+          "LEARN_MORE",
+          "SHOP_NOW",
+          "DOWNLOAD",
+          "SIGN_UP",
+          "CONTACT_US",
+          "BOOK_NOW"
+        ],
+        "composition_model": "deterministic"
+      }
+    },
+    {
+      "capability_id": "meta_feed_image",
+      "display_name": "Meta Feed Image (Instagram + Facebook)",
+      "format_kind": "image",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/translated/meta",
+          "id": "meta_feed_image"
+        }
+      ],
+      "applies_to_property_ids": [
+        "instagram",
+        "facebook"
+      ],
+      "params": {
+        "width": 1080,
+        "height": 1080,
+        "aspect_ratio": "1:1",
+        "max_file_size_kb": 30720,
+        "image_formats": [
+          "jpg",
+          "png"
+        ],
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125,
+        "cta_values": [
+          "LEARN_MORE",
+          "SHOP_NOW",
+          "DOWNLOAD",
+          "SIGN_UP",
+          "CONTACT_US",
+          "BOOK_NOW"
+        ]
+      }
+    },
+    {
+      "capability_id": "meta_stories_video",
+      "display_name": "Meta Stories Video (Instagram + Facebook)",
+      "format_kind": "video_hosted",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/translated/meta",
+          "id": "meta_stories_video"
+        }
+      ],
+      "applies_to_property_ids": [
+        "instagram",
+        "facebook"
+      ],
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_range": [
+          1000,
+          60000
+        ],
+        "min_width": 1080,
+        "min_height": 1920,
+        "video_codecs": [
+          "h264"
+        ],
+        "audio_codecs": [
+          "aac"
+        ],
+        "containers": [
+          "mp4"
+        ],
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125,
+        "cta_values": [
+          "LEARN_MORE",
+          "SHOP_NOW",
+          "DOWNLOAD",
+          "SIGN_UP"
+        ]
+      }
+    },
+    {
+      "capability_id": "meta_feed_carousel",
+      "display_name": "Meta Feed Carousel (Instagram + Facebook)",
+      "format_kind": "image_carousel",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/translated/meta",
+          "id": "meta_feed_carousel"
+        }
+      ],
+      "applies_to_property_ids": [
+        "instagram",
+        "facebook"
+      ],
+      "experimental": true,
+      "params": {
+        "cards_min": 2,
+        "cards_max": 10,
+        "card_aspect_ratio": "1:1",
+        "card_width": 1080,
+        "card_height": 1080,
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125
+      }
+    }
+  ],
+  "placements": [
+    {
+      "placement_id": "instagram_reels",
+      "name": "Instagram Reels",
+      "tags": [
+        "reels",
+        "vertical_video",
+        "social"
+      ],
+      "property_ids": [
+        "instagram"
+      ],
+      "format_options": [
+        {
+          "capability_id": "meta_reels"
+        }
+      ]
+    },
+    {
+      "placement_id": "facebook_reels",
+      "name": "Facebook Reels",
+      "tags": [
+        "reels",
+        "vertical_video",
+        "social"
+      ],
+      "property_ids": [
+        "facebook"
+      ],
+      "format_options": [
+        {
+          "capability_id": "meta_reels"
+        }
+      ]
+    },
+    {
+      "placement_id": "instagram_feed",
+      "name": "Instagram Feed",
+      "tags": [
+        "feed",
+        "social"
+      ],
+      "property_ids": [
+        "instagram"
+      ],
+      "format_options": [
+        {
+          "capability_id": "meta_feed_image"
+        },
+        {
+          "capability_id": "meta_feed_carousel"
+        }
+      ]
+    },
+    {
+      "placement_id": "instagram_stories",
+      "name": "Instagram Stories",
+      "tags": [
+        "stories",
+        "vertical_video",
+        "social"
+      ],
+      "property_ids": [
+        "instagram"
+      ],
+      "format_options": [
+        {
+          "capability_id": "meta_stories_video"
+        }
+      ]
+    }
+  ],
+  "placement_tags": {
+    "reels": {
+      "name": "Reels",
+      "description": "Short-form vertical video placements"
+    },
+    "vertical_video": {
+      "name": "Vertical Video",
+      "description": "9:16 aspect-ratio video surfaces"
+    },
+    "social": {
+      "name": "Social",
+      "description": "In-feed social placements"
+    },
+    "feed": {
+      "name": "Feed",
+      "description": "Main social feed surface"
+    },
+    "stories": {
+      "name": "Stories",
+      "description": "Ephemeral full-screen story surface"
+    }
+  },
+  "authorized_agents": [
+    {
+      "url": "https://creative.adcontextprotocol.org/translated/meta/agent",
+      "authorized_for": "Community-registry advisory only \u2014 not a Meta-authorized sales path. Routes buyers to the Meta-direct API. Once Meta publishes their own adagents.json at facebook.com/.well-known/adagents.json with real authorized_agents[], this file deprecates.",
+      "authorization_type": "property_tags",
+      "property_tags": [
+        "meta_network"
+      ],
+      "delegation_type": "ad_network"
+    }
+  ],
+  "last_updated": "2026-05-17T00:00:00Z"
+}
diff --git a/static/examples/format-schemas/README.md b/static/examples/format-schemas/README.md
new file mode 100644
index 0000000000..37d5b402e2
--- /dev/null
+++ b/static/examples/format-schemas/README.md
@@ -0,0 +1,63 @@
+# `format_schema` Fetch-Contract Test Fixtures
+
+Reference fixtures for adopters implementing the `format_schema` fetch contract on `product-format-declaration.json#format_schema` (also applies to `platform_extensions[]` refs — the *transport* contract is identical regardless of the field name; only the *consumption* semantics differ).
+
+The normative contract is documented at `static/schemas/source/core/product-format-declaration.json#format_schema` and in `docs/creative/canonical-formats.mdx#format_schema-fetch-contract-normative`. This directory provides paired positive + negative test vectors so reference SDKs (`adcp-client`, `adcp-go`, the Python SDK) converge on the same behavior.
+
+## Layout
+
+- `positive/` — well-formed responses that MUST validate cleanly
+- `negative/` — adversarial responses that MUST be rejected per the contract
+- Each fixture is a `.json` file describing the test vector (request URI shape, response payload or simulated failure, expected SDK outcome). Where the test requires non-JSON behavior (e.g., HTTP redirect chain, RFC 1918 target), the fixture documents the SETUP that simulates the failure rather than the response body itself.
+
+## Expected SDK outcomes
+
+| Outcome | Meaning |
+|---|---|
+| `pass` | Fetch + validate succeed; SDK consumes the schema |
+| `fail:digest_mismatch` | SHA-256 of body ≠ declared digest; SDK MUST treat as unresolved + surface error |
+| `fail:transport` | Scheme / redirect / SSRF / timeout / size violation; SDK MUST refuse to fetch or hard-fail |
+| `fail:schema_invalid` | Body parses as JSON but isn't a valid JSON Schema; SDK MUST treat as unresolved |
+| `fail:ref_violation` | `$ref` violates sandboxing (cross-origin, depth, count); SDK MUST reject |
+| `fail:budget_exceeded` | Schema compile / validation exceeds CPU/memory budget; SDK MUST treat manifest as invalid |
+
+## Categories covered (per the contract's 7 failure modes)
+
+| Category | Positive | Negative |
+|---|---|---|
+| **Digest verification** | `positive/01_well_formed_digest_match.json` (body matches declared sha256) | `negative/01_digest_mismatch.json` (declared digest ≠ actual sha256) |
+| **Transport** | (covered by positive/01 — https + 200 + size + timeout) | `negative/02_http_scheme.json` (http:// rejected), `negative/03_redirect_chain.json` (302/301 followed → MUST fail), `negative/04_oversized_body.json` (>1 MiB → cap during streaming) |
+| **SSRF guards** | (covered by transport rules in positive/01) | `negative/05_ssrf_rfc1918.json` (target resolves to 10.0.0.0/8), `negative/06_ssrf_metadata_endpoint.json` (169.254.169.254 / metadata.google.internal) |
+| **`$ref` sandboxing** | `positive/02_intra_document_ref.json` (same-origin + intra-document refs only) | `negative/07_ref_cross_origin.json` (cross-origin $ref → reject), `negative/08_ref_depth_exceeded.json` (transitive chain > 8 deep) |
+| **Schema-compile budget** | (covered by positive/01) | `negative/09_catastrophic_regex.json` (pattern with exponential backtracking) |
+| **Schema validity** | (covered by positive/01 — body is valid Draft 07 JSON Schema) | `negative/10_invalid_schema.json` (body is JSON but not a valid schema) |
+| **Graceful degradation** | `positive/03_cached_after_404.json` (cache-hit on previously-fetched URI@digest survives a 404 on re-fetch) | `negative/11_persistent_404.json` (no cache, no previous fetch → SDK MUST treat declaration as unresolved + emit errors[]) |
+
+## Using these fixtures
+
+Reference implementations should write a test runner that walks each fixture, simulates the described condition (using a local HTTP mock, a malformed digest, or a regex-eval timer), and asserts the SDK's outcome matches the fixture's `expected_outcome` field. The test runner is NOT included here — the spec defines behavior, fixtures define test inputs, and each SDK author wires their own runner per language conventions.
+
+[Issue #4699](https://github.com/adcontextprotocol/adcp/issues/4699) tracks adding a cross-SDK conformance harness that walks these fixtures uniformly. Until then: each SDK validates against the fixtures independently and reports outcomes for cross-comparison.
+
+## Field shape (all fixtures)
+
+```jsonc
+{
+  "test_id": "fetch-contract-01-digest-mismatch",
+  "category": "digest_verification" | "transport" | "ssrf" | "ref_sandbox" | "compile_budget" | "schema_validity" | "graceful_degradation",
+  "description": "Short prose describing the scenario",
+  "setup": {
+    // What the test runner needs to arrange — varies by category
+    "request_uri": "https://example.invalid/extensions/x",
+    "declared_digest": "sha256:abcd...",
+    "response_status": 200,
+    "response_body_sha256": "sha256:0000...",   // actual body hash (mismatch case)
+    "response_body": { /* inline body OR reference */ },
+    "response_headers": { "Content-Type": "application/json" }
+    // category-specific keys: redirect_chain, body_size_bytes, target_ip, $ref_chain, etc.
+  },
+  "expected_outcome": "fail:digest_mismatch",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",   // when the SDK should emit a structured advisory
+  "rationale": "Why the contract requires this specific outcome — links to the contract clause"
+}
+```
diff --git a/static/examples/format-schemas/negative/01_digest_mismatch.json b/static/examples/format-schemas/negative/01_digest_mismatch.json
new file mode 100644
index 0000000000..cae731975b
--- /dev/null
+++ b/static/examples/format-schemas/negative/01_digest_mismatch.json
@@ -0,0 +1,36 @@
+{
+  "test_id": "fetch-contract-neg-01-digest-mismatch",
+  "category": "digest_verification",
+  "description": "Body bytes parse as a valid JSON Schema, but sha256(body) != declared digest. Either a substitution attack or producer error \u2014 either way, MUST hard-fail.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/mismatched",
+    "declared_digest": "sha256:0000000000000000000000000000000000000000000000000000000000000000",
+    "response_status": 200,
+    "response_body": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "$id": "/schemas/test/format-shape-x.json",
+      "title": "Test Format Shape X",
+      "type": "object",
+      "properties": {
+        "headline": {
+          "type": "string",
+          "maxLength": 60
+        },
+        "image_url": {
+          "type": "string",
+          "format": "uri"
+        }
+      },
+      "required": [
+        "headline"
+      ]
+    },
+    "response_body_sha256": "sha256:<some_other_real_hash>",
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "fail:digest_mismatch",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Digest mismatch is a hard fail. SDK MUST treat the format declaration as unresolvable and MUST NOT validate manifests against the mismatched body. MUST NOT cache the mismatch as a negative result keyed on uri alone (defeats CDN-flap recovery)."
+}
diff --git a/static/examples/format-schemas/negative/02_http_scheme.json b/static/examples/format-schemas/negative/02_http_scheme.json
new file mode 100644
index 0000000000..339248201a
--- /dev/null
+++ b/static/examples/format-schemas/negative/02_http_scheme.json
@@ -0,0 +1,13 @@
+{
+  "test_id": "fetch-contract-neg-02-http-scheme",
+  "category": "transport",
+  "description": "Request URI uses http:// (or file://, data:, anything non-https). SDK MUST refuse to fetch at the schema layer.",
+  "setup": {
+    "request_uri": "http://creative.adcontextprotocol.org/extensions/insecure",
+    "declared_digest": "sha256:<irrelevant>",
+    "fetch_attempted": false
+  },
+  "expected_outcome": "fail:transport",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "https-only is enforced at the schema layer (platform-extension-ref.json pattern ^https://). Defense-in-depth: even if a malformed schema slips through, the fetch contract requires https-only refusal before any network operation."
+}
diff --git a/static/examples/format-schemas/negative/03_redirect_chain.json b/static/examples/format-schemas/negative/03_redirect_chain.json
new file mode 100644
index 0000000000..e8c98cd37e
--- /dev/null
+++ b/static/examples/format-schemas/negative/03_redirect_chain.json
@@ -0,0 +1,16 @@
+{
+  "test_id": "fetch-contract-neg-03-redirect-chain",
+  "category": "transport",
+  "description": "Origin responds 302 to a different URL. SDK MUST disable HTTP redirects and treat the 302 as a hard failure (NOT follow).",
+  "setup": {
+    "request_uri": "https://example.com/extensions/redirected",
+    "declared_digest": "sha256:<irrelevant>",
+    "response_status": 302,
+    "response_headers": {
+      "Location": "https://creative.adcontextprotocol.org/extensions/elsewhere"
+    }
+  },
+  "expected_outcome": "fail:transport",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Open redirects are a free SSRF primitive. The contract requires redirects disabled. If a follow IS implemented, the redirect target MUST pass the same scheme + SSRF + allowlist checks \u2014 but the simpler and stricter posture is no-follow."
+}
diff --git a/static/examples/format-schemas/negative/04_oversized_body.json b/static/examples/format-schemas/negative/04_oversized_body.json
new file mode 100644
index 0000000000..8a371d18ee
--- /dev/null
+++ b/static/examples/format-schemas/negative/04_oversized_body.json
@@ -0,0 +1,17 @@
+{
+  "test_id": "fetch-contract-neg-04-oversized-body",
+  "category": "transport",
+  "description": "Response body exceeds 1 MiB. SDK MUST enforce the cap during streaming (not after full buffer) \u2014 never load >1 MiB into memory just to fail.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/oversized",
+    "declared_digest": "sha256:<irrelevant>",
+    "response_status": 200,
+    "response_body_size_bytes": 2097152,
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "fail:transport",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Streaming cap at 1 MiB. Over-cap hard-fails identically to digest mismatch. Cap before full buffering \u2014 a 1 GiB response should fail the connection at the 1 MiB mark, not after the full body is downloaded."
+}
diff --git a/static/examples/format-schemas/negative/05_ssrf_rfc1918.json b/static/examples/format-schemas/negative/05_ssrf_rfc1918.json
new file mode 100644
index 0000000000..b36b86dd13
--- /dev/null
+++ b/static/examples/format-schemas/negative/05_ssrf_rfc1918.json
@@ -0,0 +1,14 @@
+{
+  "test_id": "fetch-contract-neg-05-ssrf-rfc1918",
+  "category": "ssrf",
+  "description": "Request URI's hostname resolves to an RFC 1918 private-space address (e.g., 10.0.0.0/8). SDK MUST resolve the hostname before fetching and reject.",
+  "setup": {
+    "request_uri": "https://internal.example.invalid/extensions/x",
+    "declared_digest": "sha256:<irrelevant>",
+    "resolved_ip": "10.99.99.99",
+    "fetch_attempted": false
+  },
+  "expected_outcome": "fail:transport",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "RFC 1918 (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback (127.0.0.0/8, ::1), link-local (169.254.0.0/16, fe80::/10), CGNAT (100.64.0.0/10), and any RFC 6761 special-use name MUST be rejected. SDK MUST pin the connection to the resolved IP (or re-resolve and re-validate per request) to defeat DNS rebinding."
+}
diff --git a/static/examples/format-schemas/negative/06_ssrf_metadata_endpoint.json b/static/examples/format-schemas/negative/06_ssrf_metadata_endpoint.json
new file mode 100644
index 0000000000..aefbb7e70a
--- /dev/null
+++ b/static/examples/format-schemas/negative/06_ssrf_metadata_endpoint.json
@@ -0,0 +1,13 @@
+{
+  "test_id": "fetch-contract-neg-06-ssrf-metadata",
+  "category": "ssrf",
+  "description": "Request URI targets a cloud metadata endpoint (AWS 169.254.169.254, GCP metadata.google.internal, K8s kubernetes.default.svc, etc.). These are credential-leak primitives \u2014 MUST reject regardless of declared digest.",
+  "setup": {
+    "request_uri": "https://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/token",
+    "declared_digest": "sha256:<irrelevant>",
+    "fetch_attempted": false
+  },
+  "expected_outcome": "fail:transport",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Cloud metadata endpoints are explicitly forbidden by the contract. A schema-fetch primitive used to leak instance credentials would be a critical multi-tenant compromise. Reject by both hostname denylist AND resolved-IP denylist (defense in depth)."
+}
diff --git a/static/examples/format-schemas/negative/07_ref_cross_origin.json b/static/examples/format-schemas/negative/07_ref_cross_origin.json
new file mode 100644
index 0000000000..8f4f109eb9
--- /dev/null
+++ b/static/examples/format-schemas/negative/07_ref_cross_origin.json
@@ -0,0 +1,26 @@
+{
+  "test_id": "fetch-contract-neg-07-ref-cross-origin",
+  "category": "ref_sandbox",
+  "description": "Fetched body's $ref points at an arbitrary cross-origin URI (not same-origin, not AAO mirror, not intra-document). SDK MUST reject the reference and treat the parent schema as unresolvable.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/with_bad_ref",
+    "declared_digest": "sha256:<computed_from_response_body>",
+    "response_status": 200,
+    "response_body": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "$id": "/schemas/test/cross-origin-ref.json",
+      "type": "object",
+      "properties": {
+        "value": {
+          "$ref": "https://attacker.example/leak"
+        }
+      }
+    },
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "fail:ref_violation",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Cross-origin $ref is a free SSRF primitive once inside the schema body. Sandboxing requires: same-origin (after RFC 3986 \u00a76 normalization), AAO mirror namespace, or intra-document #/... JSON Pointer only. $ref: file://... MUST be rejected unconditionally."
+}
diff --git a/static/examples/format-schemas/negative/08_ref_depth_exceeded.json b/static/examples/format-schemas/negative/08_ref_depth_exceeded.json
new file mode 100644
index 0000000000..bd44a0e660
--- /dev/null
+++ b/static/examples/format-schemas/negative/08_ref_depth_exceeded.json
@@ -0,0 +1,17 @@
+{
+  "test_id": "fetch-contract-neg-08-ref-depth-exceeded",
+  "category": "ref_sandbox",
+  "description": "Transitive $ref chain exceeds depth 8 (or total $ref count exceeds 256). SDK MUST bound both depth and breadth before resolution.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/deep_refs",
+    "declared_digest": "sha256:<computed>",
+    "response_status": 200,
+    "response_body_summary": "Schema with $ref chain a -> b -> c -> d -> e -> f -> g -> h -> i (9 deep)",
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "fail:ref_violation",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Depth <= 8 AND $ref count <= 256 across the resolved tree. Depth 8 with breadth 100 per level is 10^16 nodes \u2014 depth alone isn't enough."
+}
diff --git a/static/examples/format-schemas/negative/09_catastrophic_regex.json b/static/examples/format-schemas/negative/09_catastrophic_regex.json
new file mode 100644
index 0000000000..03b984996d
--- /dev/null
+++ b/static/examples/format-schemas/negative/09_catastrophic_regex.json
@@ -0,0 +1,27 @@
+{
+  "test_id": "fetch-contract-neg-09-catastrophic-regex",
+  "category": "compile_budget",
+  "description": "Schema contains a 'pattern' regex with exponential backtracking (e.g., ^(a+)+$ against aaaaaaaaaaaaaaaaaaaaX). Evaluating this regex pins a CPU forever; SDK MUST use a non-backtracking engine (re2) or per-pattern timeout.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/bad_regex",
+    "declared_digest": "sha256:<computed>",
+    "response_status": 200,
+    "response_body": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "$id": "/schemas/test/bad-regex.json",
+      "type": "object",
+      "properties": {
+        "input": {
+          "type": "string",
+          "pattern": "^(a+)+$"
+        }
+      }
+    },
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "fail:budget_exceeded",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Schema-compile bounds: compiled-schema keyword count <= 10 000, patterns evaluated via re2 OR per-pattern timeout, per-manifest validation budget <= 250 ms. Without these, a 'valid' schema with catastrophic backtracking is a DoS vector."
+}
diff --git a/static/examples/format-schemas/negative/10_invalid_schema.json b/static/examples/format-schemas/negative/10_invalid_schema.json
new file mode 100644
index 0000000000..596d723005
--- /dev/null
+++ b/static/examples/format-schemas/negative/10_invalid_schema.json
@@ -0,0 +1,25 @@
+{
+  "test_id": "fetch-contract-neg-10-invalid-schema",
+  "category": "schema_validity",
+  "description": "Body parses as JSON but isn't a valid JSON Schema (Draft 07 or 2020-12). SDK MUST treat as unresolvable; MUST NOT attempt partial validation.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/not_a_schema",
+    "declared_digest": "sha256:<computed_from_response_body>",
+    "response_status": 200,
+    "response_body": {
+      "this_is": "not a JSON schema",
+      "missing": [
+        "$schema",
+        "$id",
+        "type",
+        "properties"
+      ]
+    },
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "fail:schema_invalid",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Schema-validity is part of the contract. If body is JSON but not a valid schema, SDK MUST surface unresolvable rather than silently downgrading to 'best-effort' validation."
+}
diff --git a/static/examples/format-schemas/negative/11_persistent_404.json b/static/examples/format-schemas/negative/11_persistent_404.json
new file mode 100644
index 0000000000..06438de6bd
--- /dev/null
+++ b/static/examples/format-schemas/negative/11_persistent_404.json
@@ -0,0 +1,14 @@
+{
+  "test_id": "fetch-contract-neg-11-persistent-404",
+  "category": "graceful_degradation",
+  "description": "SDK has no cached body for this URI@digest. Origin returns persistent 404. SDK MUST degrade gracefully \u2014 treat the declaration as unresolved, skip from format_options, surface via errors[] (NOT fail the whole get_products response).",
+  "setup": {
+    "request_uri": "https://example.invalid/extensions/missing",
+    "declared_digest": "sha256:<irrelevant>",
+    "cache_state": "no_prior_fetch",
+    "response_status": 404
+  },
+  "expected_outcome": "fail:transport",
+  "expected_error_code": "FORMAT_PROJECTION_FAILED",
+  "rationale": "Graceful degradation: 404 / network partition / persistent fetch failure MUST surface via errors[] (the declaration is unresolved for this session) without failing the entire get_products response. The buy stays viable on the v1 path; only this v2 format declaration is absent."
+}
diff --git a/static/examples/format-schemas/positive/01_well_formed_digest_match.json b/static/examples/format-schemas/positive/01_well_formed_digest_match.json
new file mode 100644
index 0000000000..cb96a0919a
--- /dev/null
+++ b/static/examples/format-schemas/positive/01_well_formed_digest_match.json
@@ -0,0 +1,34 @@
+{
+  "test_id": "fetch-contract-pos-01-well-formed",
+  "category": "digest_verification",
+  "description": "Well-formed response: https + 200 + body parses as JSON + body sha256 matches declared digest + schema-compile under budget. The happy path.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/test_format_shape_x",
+    "declared_digest": "sha256:<computed_from_response_body>",
+    "response_status": 200,
+    "response_body": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "$id": "/schemas/test/format-shape-x.json",
+      "title": "Test Format Shape X",
+      "type": "object",
+      "properties": {
+        "headline": {
+          "type": "string",
+          "maxLength": 60
+        },
+        "image_url": {
+          "type": "string",
+          "format": "uri"
+        }
+      },
+      "required": [
+        "headline"
+      ]
+    },
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "pass",
+  "rationale": "All contract gates pass: https-only OK, no redirect OK, body <=1 MiB OK, sha256 matches OK, valid Draft 07 OK, compile within budget OK."
+}
diff --git a/static/examples/format-schemas/positive/02_intra_document_ref.json b/static/examples/format-schemas/positive/02_intra_document_ref.json
new file mode 100644
index 0000000000..e7e70100b1
--- /dev/null
+++ b/static/examples/format-schemas/positive/02_intra_document_ref.json
@@ -0,0 +1,38 @@
+{
+  "test_id": "fetch-contract-pos-02-intra-document-ref",
+  "category": "ref_sandbox",
+  "description": "Body uses $ref: '#/definitions/foo' intra-document JSON Pointer; SDK MUST resolve to the parent document's parsed tree.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/test_with_intra_ref",
+    "declared_digest": "sha256:<computed_from_response_body>",
+    "response_status": 200,
+    "response_body": {
+      "$schema": "http://json-schema.org/draft-07/schema#",
+      "$id": "/schemas/test/format-shape-with-ref.json",
+      "type": "object",
+      "definitions": {
+        "size_constraint": {
+          "type": "object",
+          "properties": {
+            "width": {
+              "type": "integer"
+            },
+            "height": {
+              "type": "integer"
+            }
+          }
+        }
+      },
+      "properties": {
+        "size": {
+          "$ref": "#/definitions/size_constraint"
+        }
+      }
+    },
+    "response_headers": {
+      "Content-Type": "application/json"
+    }
+  },
+  "expected_outcome": "pass",
+  "rationale": "Intra-document $ref (JSON Pointer) is bounded to the parent document's parsed tree per the contract. No external fetch triggered."
+}
diff --git a/static/examples/format-schemas/positive/03_cached_after_404.json b/static/examples/format-schemas/positive/03_cached_after_404.json
new file mode 100644
index 0000000000..e14d139c55
--- /dev/null
+++ b/static/examples/format-schemas/positive/03_cached_after_404.json
@@ -0,0 +1,14 @@
+{
+  "test_id": "fetch-contract-pos-03-cached-after-404",
+  "category": "graceful_degradation",
+  "description": "SDK previously fetched and cached the schema by uri@digest. Subsequent fetch returns 404 (CDN flap / origin partition). SDK MUST serve the cached body \u2014 uri@digest is immutable per the contract.",
+  "setup": {
+    "request_uri": "https://creative.adcontextprotocol.org/extensions/previously_cached",
+    "declared_digest": "sha256:<computed_from_response_body>",
+    "cache_state": "uri_at_digest_present",
+    "response_status": 404,
+    "response_body": null
+  },
+  "expected_outcome": "pass",
+  "rationale": "Cache is keyed by uri@digest, treated as immutable per the contract. SDK MUST serve cached body on transient origin failure; degrading the entire session for a 404 punishes downstream buyers for a network blip."
+}
diff --git a/static/examples/get_products_responses/canonical/meta_with_bundled_extensions.json b/static/examples/get_products_responses/canonical/meta_with_bundled_extensions.json
new file mode 100644
index 0000000000..b154dd6fa6
--- /dev/null
+++ b/static/examples/get_products_responses/canonical/meta_with_bundled_extensions.json
@@ -0,0 +1,253 @@
+{
+  "$schema": "/schemas/media-buy/get-products-response.json",
+  "products": [
+    {
+      "product_id": "meta_reels_us",
+      "name": "Meta Reels — United States",
+      "description": "9:16 vertical short-form video on Meta Reels (Facebook + Instagram). Buyers upload H.264 mp4 (3-90s) plus headline and primary text; Meta serves to Reels feeds with placement-native UI overlays and Meta-specific tracking via the meta_pixel extension.",
+      "publisher_properties": [
+        {
+          "publisher_domain": "meta.com",
+          "selection_type": "all"
+        }
+      ],
+      "channels": [
+        "social"
+      ],
+      "delivery_type": "non_guaranteed",
+      "pricing_options": [
+        {
+          "pricing_option_id": "cpm_floor",
+          "pricing_model": "cpm",
+          "currency": "USD",
+          "floor_price": 5.5
+        }
+      ],
+      "reporting_capabilities": {
+        "available_reporting_frequencies": [
+          "hourly",
+          "daily"
+        ],
+        "expected_delay_minutes": 60,
+        "timezone": "America/Los_Angeles",
+        "supports_webhooks": true,
+        "available_metrics": [
+          "impressions",
+          "clicks",
+          "spend",
+          "completion_rate",
+          "viewability"
+        ],
+        "date_range_support": "date_range"
+      },
+      "format_options": [
+        {
+          "format_kind": "video_hosted",
+          "params": {
+            "orientation": "vertical",
+            "aspect_ratio": "9:16",
+            "duration_ms_range": [
+              3000,
+              90000
+            ],
+            "min_width": 1080,
+            "min_height": 1920,
+            "max_file_size_mb": 200,
+            "video_codecs": [
+              "h264"
+            ],
+            "audio_codecs": [
+              "aac"
+            ],
+            "containers": [
+              "mp4"
+            ],
+            "headline_max_chars": 25,
+            "primary_text_max_chars": 72,
+            "captions": "recommended",
+            "cta_values": [
+              "LEARN_MORE",
+              "SHOP_NOW",
+              "DOWNLOAD",
+              "SIGN_UP"
+            ],
+            "composition_model": "deterministic",
+            "platform_extensions": [
+              {
+                "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel",
+                "digest": "sha256:a3f5b7c9d8e2f1a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2"
+              },
+              {
+                "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_placements_reels",
+                "digest": "sha256:b8e1d4f6a9c2b5e8d1f4a7c0b3e6d9f2a5c8b1e4d7f0a3c6b9e2d5f8a1c4b7e0"
+              }
+            ]
+          }
+        }
+      ]
+    },
+    {
+      "product_id": "meta_feed_image_us",
+      "name": "Meta Feed Image — United States",
+      "description": "Static image placement in Meta feed (Facebook + Instagram). 1.91:1, 1:1, or 4:5 aspect ratios accepted. Same Meta-specific tracking as Reels via meta_pixel extension.",
+      "publisher_properties": [
+        {
+          "publisher_domain": "meta.com",
+          "selection_type": "all"
+        }
+      ],
+      "channels": [
+        "social"
+      ],
+      "delivery_type": "non_guaranteed",
+      "pricing_options": [
+        {
+          "pricing_option_id": "cpm_floor",
+          "pricing_model": "cpm",
+          "currency": "USD",
+          "floor_price": 4
+        }
+      ],
+      "reporting_capabilities": {
+        "available_reporting_frequencies": [
+          "hourly",
+          "daily"
+        ],
+        "expected_delay_minutes": 60,
+        "timezone": "America/Los_Angeles",
+        "supports_webhooks": true,
+        "available_metrics": [
+          "impressions",
+          "clicks",
+          "spend",
+          "ctr",
+          "viewability"
+        ],
+        "date_range_support": "date_range"
+      },
+      "format_options": [
+        {
+          "format_kind": "image",
+          "params": {
+            "width": 1080,
+            "height": 1080,
+            "max_file_size_kb": 30000,
+            "image_formats": [
+              "jpg",
+              "png"
+            ],
+            "ssl_required": true,
+            "headline_max_chars": 40,
+            "body_text_max_chars": 125,
+            "cta_values": [
+              "LEARN_MORE",
+              "SHOP_NOW",
+              "DOWNLOAD",
+              "SIGN_UP"
+            ],
+            "composition_model": "deterministic",
+            "platform_extensions": [
+              {
+                "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel",
+                "digest": "sha256:a3f5b7c9d8e2f1a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2"
+              },
+              {
+                "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_placements_feed",
+                "digest": "sha256:c2d4e6f8a0b2c4d6e8f0a2c4d6e8f0a2c4d6e8f0a2c4d6e8f0a2c4d6e8f0a2c4"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ],
+  "extensions": {
+    "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel@sha256:a3f5b7c9d8e2f1a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2": {
+      "extends": "tracking",
+      "version": "2.1.0",
+      "description": "Meta Pixel + Conversions API integration. Required for conversion-event optimization on Meta products.",
+      "fields": {
+        "type": "object",
+        "required": [
+          "pixel_id"
+        ],
+        "properties": {
+          "pixel_id": {
+            "type": "string",
+            "pattern": "^[0-9]{15,16}$",
+            "description": "Meta Pixel ID (15-16 digit numeric)."
+          },
+          "conversion_event": {
+            "type": "string",
+            "enum": [
+              "PURCHASE",
+              "LEAD",
+              "COMPLETE_REGISTRATION",
+              "ADD_TO_CART",
+              "INITIATE_CHECKOUT",
+              "SUBSCRIBE",
+              "VIEW_CONTENT"
+            ],
+            "description": "Standard Meta conversion event the pixel fires on. Custom events use the `custom_event_name` field instead."
+          },
+          "custom_event_name": {
+            "type": "string",
+            "description": "Custom Meta conversion event name. Used when conversion_event is omitted."
+          },
+          "test_event_code": {
+            "type": "string",
+            "description": "Optional Meta Events Manager test event code for sandbox/preview verification."
+          }
+        }
+      }
+    },
+    "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_placements_reels@sha256:b8e1d4f6a9c2b5e8d1f4a7c0b3e6d9f2a5c8b1e4d7f0a3c6b9e2d5f8a1c4b7e0": {
+      "extends": "placement",
+      "version": "1.0.0",
+      "description": "Meta-specific placement enum scoped to Reels surfaces (Facebook Reels + Instagram Reels).",
+      "fields": {
+        "type": "object",
+        "properties": {
+          "placement": {
+            "type": "string",
+            "const": "reels",
+            "description": "Discriminator — products extending this surface accept only Reels placement."
+          },
+          "facebook_reels": {
+            "type": "boolean",
+            "default": true,
+            "description": "Whether Facebook Reels delivery is enabled."
+          },
+          "instagram_reels": {
+            "type": "boolean",
+            "default": true,
+            "description": "Whether Instagram Reels delivery is enabled."
+          }
+        }
+      }
+    },
+    "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_placements_feed@sha256:c2d4e6f8a0b2c4d6e8f0a2c4d6e8f0a2c4d6e8f0a2c4d6e8f0a2c4d6e8f0a2c4": {
+      "extends": "placement",
+      "version": "1.0.0",
+      "description": "Meta-specific placement enum scoped to feed surfaces (Facebook Feed + Instagram Feed).",
+      "fields": {
+        "type": "object",
+        "properties": {
+          "placement": {
+            "type": "string",
+            "const": "feed",
+            "description": "Discriminator — products extending this surface accept feed placements."
+          },
+          "facebook_feed": {
+            "type": "boolean",
+            "default": true
+          },
+          "instagram_feed": {
+            "type": "boolean",
+            "default": true
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/static/examples/products/canonical/amazon_sponsored_products.json b/static/examples/products/canonical/amazon_sponsored_products.json
new file mode 100644
index 0000000000..0aade51ac0
--- /dev/null
+++ b/static/examples/products/canonical/amazon_sponsored_products.json
@@ -0,0 +1,67 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "amazon_sp_search",
+  "name": "Amazon Sponsored Products — Search",
+  "description": "Catalog-driven sponsored product placement in Amazon search results. Buyer supplies a product catalog with ASINs; Amazon's surface composes per-item rendering (product image + title + price + rating + Prime badge) using its native placement template. Composition is deterministic — buyer can predict per-slot rendering from the catalog item structure. No buyer creative slots; the catalog reference is the entire input.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "amazon.com",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "retail_media"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpc_auction",
+      "pricing_model": "cpc",
+      "currency": "USD",
+      "floor_price": 0.5
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "hourly",
+      "daily"
+    ],
+    "expected_delay_minutes": 60,
+    "timezone": "America/Los_Angeles",
+    "supports_webhooks": true,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "conversions",
+      "conversion_value",
+      "roas",
+      "new_to_brand_rate"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "sponsored_placement",
+      "params": {
+        "supported_catalog_types": [
+          "product"
+        ],
+        "min_items": 1,
+        "max_items": 50,
+        "fanout_mode": "per_item",
+        "required_catalog_fields": [
+          "title",
+          "image_url",
+          "price"
+        ],
+        "supported_id_types": [
+          "asin"
+        ],
+        "hero_asset_supported": false,
+        "composition_model": "deterministic"
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/chatgpt_brand_mention.json b/static/examples/products/canonical/chatgpt_brand_mention.json
new file mode 100644
index 0000000000..8506bcb26e
--- /dev/null
+++ b/static/examples/products/canonical/chatgpt_brand_mention.json
@@ -0,0 +1,77 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "openai_chatgpt_sponsored_mention_us",
+  "name": "ChatGPT Sponsored Brand Mention — United States",
+  "description": "AI-surface sponsored placement on ChatGPT. Buyer supplies a BrandRef (resolving brand.json for context) plus optional offering reference; ChatGPT composes a natural-language sponsored mention within its response to a relevant user query. Composition is algorithmic — the agent chooses phrasing and presentation, with disclosure required and no buyer-fixed creative. Distinct from si_chat (which is the user-converses-with-brand's-agent pattern, brand-owned conversational surface). Parallels sponsored_placement structurally (both surface-composed) but for AI/agentic surfaces rather than retail-media catalog.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "openai.com",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "sponsored_intelligence"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_mention",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "floor_price": 18
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 1440,
+    "timezone": "UTC",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "engagement_rate"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "agent_placement",
+      "params": {
+        "output_modality": "text",
+        "max_mention_length_chars": 280,
+        "supports_offering_reference": true,
+        "supports_landing_page_url": true,
+        "tone_constraints": [
+          "factual",
+          "no_superlatives"
+        ],
+        "disclosure_required": true,
+        "composition_model": "algorithmic",
+        "slots": [
+          {
+            "asset_group_id": "offering_ref",
+            "required": false,
+            "asset_type": "text",
+            "description": "Optional offering identifier to focus the mention on a specific product, service, or campaign within the brand."
+          },
+          {
+            "asset_group_id": "landing_page_url",
+            "required": false,
+            "asset_type": "url",
+            "description": "Optional URL the surface MAY attach to mentions as a citation or learn-more link."
+          }
+        ],
+        "platform_extensions": [
+          {
+            "uri": "https://creative.adcontextprotocol.org/translated/openai/extensions/chatgpt_response_card",
+            "digest": "sha256:f3a6c9b2e5d8f1a4c7b0e3d6f9a2c5b8e1d4f7a0c3b6e9d2f5a8c1b4e7d0f3a6"
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/gam_3p_display_tag.json b/static/examples/products/canonical/gam_3p_display_tag.json
new file mode 100644
index 0000000000..93283b2cd1
--- /dev/null
+++ b/static/examples/products/canonical/gam_3p_display_tag.json
@@ -0,0 +1,85 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "gam_publisher_3p_display_tag_300x250",
+  "name": "GAM Publisher \u2014 3P Display Tag (300\u00d7250)",
+  "description": "Third-party-served display tag (JS or iframe) on a GAM-managed publisher placement. Buyer's adserver hosts the creative; the publisher calls the tag URL at impression time. 200KB max-snippet-size and a runtime allowlist (no eval, no document.write, no setTimeout, no javascript: / data: URLs in click trackers) apply at the GAM level \u2014 these are publisher-policy constraints, not protocol-level.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "examplepublisher.example",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "display"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_floor",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "floor_price": 1.5
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "UTC",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "display_tag",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_js"
+        }
+      ],
+      "params": {
+        "width": 300,
+        "height": 250,
+        "supported_tag_types": [
+          "iframe",
+          "javascript",
+          "1x1_redirect"
+        ],
+        "ssl_required": true,
+        "max_redirect_depth": 4,
+        "max_response_time_ms": 1500,
+        "backup_image_required": true,
+        "backup_image_max_size_kb": 50,
+        "om_sdk_required": false,
+        "composition_model": "deterministic",
+        "slots": [
+          {
+            "asset_group_id": "tag_url",
+            "asset_type": "url",
+            "required": true
+          },
+          {
+            "asset_group_id": "backup_image",
+            "asset_type": "image",
+            "required": true,
+            "max_size_kb": 50
+          },
+          {
+            "asset_group_id": "landing_page_url",
+            "asset_type": "url",
+            "required": false
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/google_performance_max.json b/static/examples/products/canonical/google_performance_max.json
new file mode 100644
index 0000000000..940ba4521a
--- /dev/null
+++ b/static/examples/products/canonical/google_performance_max.json
@@ -0,0 +1,93 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "google_pmax_us",
+  "name": "Google Performance Max — United States",
+  "description": "Google Performance Max campaign — buyer supplies a pool of typed assets (multiple headlines, descriptions, landscape/square images, videos, logos) and Google's optimizer composes combinations across Search, Display, YouTube, Discover, Gmail, and Maps. Composition is algorithmic — surface picks combinations and reports per-asset performance breakdowns. Industry term: \"Responsive\" (Google) / \"Advantage+ creative\" (Meta) / \"Dynamic Creative\" (older Meta term). Distinct from sponsored_placement (catalog-driven, deterministic) and agent_placement (AI-surface composition).",
+  "publisher_properties": [
+    {
+      "publisher_domain": "google.com",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "search",
+    "display",
+    "ctv",
+    "olv"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpa_purchase",
+      "pricing_model": "cpa",
+      "event_type": "purchase",
+      "currency": "USD",
+      "fixed_price": 25
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "America/Los_Angeles",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "conversions",
+      "conversion_value",
+      "cost_per_acquisition",
+      "roas",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "responsive_creative",
+      "params": {
+        "headlines_min": 3,
+        "headlines_max": 15,
+        "headline_max_chars": 30,
+        "long_headlines_min": 1,
+        "long_headlines_max": 5,
+        "long_headline_max_chars": 90,
+        "descriptions_min": 2,
+        "descriptions_max": 5,
+        "description_max_chars": 90,
+        "images_landscape_min": 1,
+        "images_landscape_max": 20,
+        "images_landscape_aspect_ratio": "1.91:1",
+        "images_square_min": 1,
+        "images_square_max": 20,
+        "videos_min": 0,
+        "videos_max": 5,
+        "video_min_duration_ms": 10000,
+        "video_max_duration_ms": 600000,
+        "logo_min": 1,
+        "logo_max": 5,
+        "logo_aspect_ratios": [
+          "1:1",
+          "4:1"
+        ],
+        "business_name_max_chars": 25,
+        "asset_image_max_file_size_kb": 5120,
+        "supports_catalog_input": true,
+        "composition_model": "algorithmic",
+        "platform_extensions": [
+          {
+            "uri": "https://creative.adcontextprotocol.org/translated/google/extensions/google_conversion_actions",
+            "digest": "sha256:d8f1a4c7b0e3d6f9a2c5b8e1d4f7a0c3b6e9d2f5a8c1b4e7d0f3a6c9b2e5d8f1"
+          },
+          {
+            "uri": "https://creative.adcontextprotocol.org/translated/google/extensions/google_audience_signals",
+            "digest": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/meta_carousel.json b/static/examples/products/canonical/meta_carousel.json
new file mode 100644
index 0000000000..de6ca9be92
--- /dev/null
+++ b/static/examples/products/canonical/meta_carousel.json
@@ -0,0 +1,88 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "meta_carousel_us",
+  "name": "Meta Carousel — United States",
+  "description": "Multi-card swipeable carousel on Meta feed (Facebook + Instagram). 2-10 cards, square aspect, polymorphic per-card asset (image OR video). Each card carries its own headline + click URL. Surface composes the swipeable presentation; buyer ships the cards array.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "meta.com",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "social"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_floor",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "floor_price": 4.5
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "hourly",
+      "daily"
+    ],
+    "expected_delay_minutes": 60,
+    "timezone": "America/Los_Angeles",
+    "supports_webhooks": true,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "engagement_rate",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "image_carousel",
+      "params": {
+        "card_aspect_ratio": "1:1",
+        "min_cards": 2,
+        "max_cards": 10,
+        "allowed_card_asset_types": [
+          "image",
+          "video"
+        ],
+        "card_image_max_file_size_kb": 30000,
+        "card_video_max_duration_ms": 240000,
+        "primary_text_max_chars": 125,
+        "card_headline_max_chars": 40,
+        "ssl_required": true,
+        "composition_model": "deterministic",
+        "slots": [
+          {
+            "asset_group_id": "cards",
+            "asset_type": "object",
+            "required": true,
+            "min": 2,
+            "max": 10
+          },
+          {
+            "asset_group_id": "primary_text",
+            "asset_type": "text",
+            "required": false,
+            "max_chars": 125
+          },
+          {
+            "asset_group_id": "landing_page_url",
+            "asset_type": "url",
+            "required": true
+          }
+        ],
+        "platform_extensions": [
+          {
+            "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel",
+            "digest": "sha256:a3f5b7c9d8e2f1a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2"
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/meta_reels_us.json b/static/examples/products/canonical/meta_reels_us.json
new file mode 100644
index 0000000000..feb3033d13
--- /dev/null
+++ b/static/examples/products/canonical/meta_reels_us.json
@@ -0,0 +1,85 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "meta_reels_us",
+  "name": "Meta Reels \u2014 United States",
+  "description": "9:16 vertical short-form video on Meta Reels (Facebook + Instagram). Buyers upload H.264 mp4 (3-90s) plus headline and primary text; Meta serves to Reels feeds with placement-native UI overlays. Conversion tracking is campaign-scoped and configured via `sync_event_sources` (event_log surface) — NOT via the creative format declaration.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "meta.com",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "social"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_floor",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "floor_price": 5.5
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "hourly",
+      "daily"
+    ],
+    "expected_delay_minutes": 60,
+    "timezone": "America/Los_Angeles",
+    "supports_webhooks": true,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "completion_rate",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "video_hosted",
+      "capability_id": "meta_reels",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/translated/meta",
+          "id": "meta_reels"
+        }
+      ],
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_range": [
+          3000,
+          90000
+        ],
+        "min_width": 1080,
+        "min_height": 1920,
+        "max_file_size_mb": 200,
+        "video_codecs": [
+          "h264"
+        ],
+        "audio_codecs": [
+          "aac"
+        ],
+        "containers": [
+          "mp4"
+        ],
+        "headline_max_chars": 40,
+        "primary_text_max_chars": 125,
+        "captions": "recommended",
+        "cta_values": [
+          "LEARN_MORE",
+          "SHOP_NOW",
+          "DOWNLOAD",
+          "SIGN_UP",
+          "CONTACT_US",
+          "BOOK_NOW"
+        ],
+        "composition_model": "deterministic"
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/nytimes_homepage_html5.json b/static/examples/products/canonical/nytimes_homepage_html5.json
new file mode 100644
index 0000000000..6fcb407c94
--- /dev/null
+++ b/static/examples/products/canonical/nytimes_homepage_html5.json
@@ -0,0 +1,70 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "nytimes_homepage_html5",
+  "name": "NYTimes.com Homepage HTML5 Banner (300\u00d7250)",
+  "description": "IAB Medium Rectangle (300\u00d7250) interactive HTML5 banner placement on the NYTimes.com homepage. Buyers upload an HTML5 zip bundle (\u2264200KB initial load, \u2264500KB polite-load with host_initiated_subload, max 30s animation, OM-SDK + clickTag macro). Different canonical from the static image MREC because the tracking model is fundamentally different (MRAID + OM-SDK vs impression pixel + click URL).",
+  "publisher_properties": [
+    {
+      "publisher_domain": "nytimes.com",
+      "selection_type": "by_id",
+      "property_ids": [
+        "homepage_above_fold"
+      ]
+    }
+  ],
+  "channels": [
+    "display"
+  ],
+  "delivery_type": "guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_homepage_html5",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "fixed_price": 28
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "America/New_York",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "viewability",
+      "engagement_rate"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "html5",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_300x250_html"
+        }
+      ],
+      "params": {
+        "width": 300,
+        "height": 250,
+        "max_initial_load_kb": 200,
+        "max_polite_load_kb": 500,
+        "host_initiated_subload": true,
+        "max_animation_duration_ms": 30000,
+        "max_cpu_load_percent": 30,
+        "om_sdk_required": true,
+        "clicktag_macro": "clickTag",
+        "backup_image_required": true,
+        "backup_image_max_size_kb": 50,
+        "ssl_required": true,
+        "composition_model": "deterministic"
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/nytimes_homepage_mrec.json b/static/examples/products/canonical/nytimes_homepage_mrec.json
new file mode 100644
index 0000000000..4537eb16b0
--- /dev/null
+++ b/static/examples/products/canonical/nytimes_homepage_mrec.json
@@ -0,0 +1,196 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "nytimes_homepage_flex_display",
+  "name": "NYTimes.com Homepage Above-the-Fold Display",
+  "description": "Flexible above-the-fold display slot on the NYTimes.com homepage. Slot accepts IAB display sizes (300\u00d7250 MREC, 728\u00d790 leaderboard, 970\u00d7250 billboard) as image, HTML5 zip, or third-party tag \u2014 the three creative shapes the same physical placement consumes. Single product, three format_options (one per creative type), each declaring `sizes[]` for the multi-size acceptance. Buyer picks the creative type they ship; size matches one of the listed pairs. Standard impression pixel + click URL tracking via universal_macros plus IAB Open Measurement viewability via the nytimes_om_strict extension.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "nytimes.com",
+      "selection_type": "by_id",
+      "property_ids": [
+        "homepage_above_fold"
+      ]
+    }
+  ],
+  "channels": [
+    "display"
+  ],
+  "delivery_type": "guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_homepage_display",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "fixed_price": 22
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "America/New_York",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "image",
+      "capability_id": "nytimes_homepage_image",
+      "display_name": "NYTimes Homepage \u2014 Image (multi-size)",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_300x250_image"
+        },
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_728x90_image"
+        },
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_970x250_image"
+        }
+      ],
+      "params": {
+        "sizes": [
+          {
+            "width": 300,
+            "height": 250
+          },
+          {
+            "width": 728,
+            "height": 90
+          },
+          {
+            "width": 970,
+            "height": 250
+          }
+        ],
+        "max_file_size_kb": 200,
+        "image_formats": [
+          "jpg",
+          "png",
+          "gif"
+        ],
+        "ssl_required": true,
+        "cta_values": [
+          "LEARN_MORE",
+          "SHOP_NOW",
+          "GET_OFFER"
+        ],
+        "composition_model": "deterministic",
+        "platform_extensions": [
+          {
+            "uri": "https://nytimes.example/extensions/nytimes_om_strict",
+            "digest": "sha256:c9d2f5b8e1a4c7b0e3d6f9a2c5b8e1d4f7a0c3b6e9d2f5a8c1b4e7d0f3a6c9b2"
+          }
+        ]
+      }
+    },
+    {
+      "format_kind": "html5",
+      "capability_id": "nytimes_homepage_html5",
+      "display_name": "NYTimes Homepage \u2014 HTML5 (multi-size)",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_300x250_html"
+        },
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_728x90_html"
+        },
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_970x250_html"
+        }
+      ],
+      "params": {
+        "sizes": [
+          {
+            "width": 300,
+            "height": 250
+          },
+          {
+            "width": 728,
+            "height": 90
+          },
+          {
+            "width": 970,
+            "height": 250
+          }
+        ],
+        "max_initial_load_kb": 200,
+        "max_polite_load_kb": 500,
+        "host_initiated_subload": true,
+        "max_animation_duration_ms": 30000,
+        "backup_image_required": true,
+        "om_sdk_required": true,
+        "composition_model": "deterministic",
+        "platform_extensions": [
+          {
+            "uri": "https://nytimes.example/extensions/nytimes_om_strict",
+            "digest": "sha256:c9d2f5b8e1a4c7b0e3d6f9a2c5b8e1d4f7a0c3b6e9d2f5a8c1b4e7d0f3a6c9b2"
+          }
+        ]
+      }
+    },
+    {
+      "format_kind": "display_tag",
+      "capability_id": "nytimes_homepage_3p_tag",
+      "display_name": "NYTimes Homepage \u2014 Third-party tag (multi-size)",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_300x250_js"
+        },
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_728x90_js"
+        },
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "display_970x250_js"
+        }
+      ],
+      "params": {
+        "sizes": [
+          {
+            "width": 300,
+            "height": 250
+          },
+          {
+            "width": 728,
+            "height": 90
+          },
+          {
+            "width": 970,
+            "height": 250
+          }
+        ],
+        "supported_tag_types": [
+          "javascript",
+          "iframe"
+        ],
+        "ssl_required": true,
+        "max_redirect_depth": 2,
+        "om_sdk_required": true,
+        "composition_model": "deterministic",
+        "platform_extensions": [
+          {
+            "uri": "https://nytimes.example/extensions/nytimes_om_strict",
+            "digest": "sha256:c9d2f5b8e1a4c7b0e3d6f9a2c5b8e1d4f7a0c3b6e9d2f5a8c1b4e7d0f3a6c9b2"
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/nytimes_homepage_takeover_custom.json b/static/examples/products/canonical/nytimes_homepage_takeover_custom.json
new file mode 100644
index 0000000000..6412e1841c
--- /dev/null
+++ b/static/examples/products/canonical/nytimes_homepage_takeover_custom.json
@@ -0,0 +1,67 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "nytimes_homepage_takeover_premium",
+  "name": "NYTimes.com Homepage Takeover (Multi-Placement Sponsorship)",
+  "description": "24-hour multi-placement homepage takeover on NYTimes.com — bundles a homepage skin, a preroll video on homepage video assets, and a sponsorship-lockup banner adjacent to top-of-page content. Sold as a unit (exclusivity_window_hours: 24). Demonstrates `format_kind: \"custom\"` with `format_shape: multi_placement_takeover` and a `format_schema` URI+digest reference pointing at NYTimes's hosted schema describing the takeover's components. Required `canonical_formats_only: true` — no v1 named format can express the multi-component shape, so SDKs MUST NOT synthesize a v1 `format_id` for this declaration.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "nytimes.com",
+      "selection_type": "by_id",
+      "property_ids": [
+        "homepage_above_fold"
+      ]
+    }
+  ],
+  "channels": [
+    "display",
+    "olv"
+  ],
+  "delivery_type": "guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "flat_takeover_24h",
+      "pricing_model": "flat_rate",
+      "currency": "USD",
+      "fixed_price": 250000
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "America/New_York",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "ctr",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "custom",
+      "canonical_formats_only": true,
+      "format_shape": "multi_placement_takeover",
+      "format_schema": {
+        "uri": "https://nytimes.example/schemas/formats/homepage_takeover_v3",
+        "digest": "sha256:e1d4f6a9c2b5e8d1f4a7c0b3e6d9f2a5c8b1e4d7f0a3c6b9e2d5f8a1c4b7e0a3"
+      },
+      "capability_id": "nytimes_homepage_takeover_premium",
+      "display_name": "Homepage Takeover — Premium Sponsorship",
+      "applies_to_channels": ["display", "olv"],
+      "params": {
+        "components": [
+          { "placement_type": "homepage_skin", "required": true },
+          { "placement_type": "preroll_video", "required": true },
+          { "placement_type": "sponsorship_lockup", "required": true }
+        ],
+        "exclusivity_window_hours": 24,
+        "ssl_required": true
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/the_daily_30s_host_read.json b/static/examples/products/canonical/the_daily_30s_host_read.json
new file mode 100644
index 0000000000..24b9f3ed87
--- /dev/null
+++ b/static/examples/products/canonical/the_daily_30s_host_read.json
@@ -0,0 +1,78 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "the_daily_30s_host_read_us",
+  "name": "The Daily — 30s Host-Read Pre-roll (US)",
+  "description": "30-second podcast host-read pre-roll on The Daily. Buyer-uploaded audio is rejected (asset_source: publisher_host_recorded); buyer submits a verbatim script (≤800 chars) as a text asset under the `script` slot, plus brand context via the manifest's BrandRef. The publisher's host records the audio, which is dynamically inserted at podcast playback time. 7-business-day production turnaround. A brief-driven host-read product would have the same shape with `creative_brief` (brief asset_type) in the slots instead of `script` (text asset_type).",
+  "publisher_properties": [
+    {
+      "publisher_domain": "thedailypod.example",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "podcast"
+  ],
+  "delivery_type": "guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_host_read",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "fixed_price": 35
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 1440,
+    "timezone": "America/New_York",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "spend",
+      "completion_rate",
+      "completed_views"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "audio_hosted",
+      "params": {
+        "duration_ms_exact": 30000,
+        "audio_codecs": [
+          "mp3",
+          "aac"
+        ],
+        "audio_sample_rates": [
+          44100,
+          48000
+        ],
+        "audio_channels": [
+          "stereo"
+        ],
+        "loudness_lufs": -16,
+        "asset_source": "publisher_host_recorded",
+        "buyer_asset_acceptance": "rejected",
+        "composition_model": "deterministic",
+        "slots": [
+          {
+            "asset_group_id": "script",
+            "required": true,
+            "asset_type": "text",
+            "max_chars": 800,
+            "description": "Verbatim script the host reads — exact wording; no improvisation; legal pre-cleared."
+          },
+          {
+            "asset_group_id": "offering_ref",
+            "required": false,
+            "asset_type": "text",
+            "description": "Optional offering identifier from the buyer's catalog to focus the host-read."
+          }
+        ],
+        "production_window_business_days": 7
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/triton_daast_audio_30s.json b/static/examples/products/canonical/triton_daast_audio_30s.json
new file mode 100644
index 0000000000..4413b4e1a7
--- /dev/null
+++ b/static/examples/products/canonical/triton_daast_audio_30s.json
@@ -0,0 +1,68 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "triton_daast_audio_30s",
+  "name": "Triton Audio DAAST (30s)",
+  "description": "DAAST 1.1 audio tag on Triton-managed streaming radio inventory. Buyer ships a DAAST tag (URL or inline XML); the streaming server fires DAAST events (impression / quartiles / click / complete / error) inherent to the spec. Audio analog of VAST.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "triton.example",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "streaming_audio",
+    "radio"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_floor",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "floor_price": 12
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 1440,
+    "timezone": "UTC",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "spend",
+      "completion_rate",
+      "completed_views",
+      "quartile_data"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "audio_daast",
+      "canonical_formats_only": true,
+      "params": {
+        "daast_version": "1.1",
+        "duration_ms_exact": 30000,
+        "linear_required": true,
+        "max_wrapper_depth": 3,
+        "ssl_required": true,
+        "companion_image_required": false,
+        "composition_model": "deterministic",
+        "slots": [
+          {
+            "asset_group_id": "daast_tag",
+            "asset_type": "daast",
+            "required": true
+          },
+          {
+            "asset_group_id": "landing_page_url",
+            "asset_type": "url",
+            "required": false
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/veo_generative_video_15s.json b/static/examples/products/canonical/veo_generative_video_15s.json
new file mode 100644
index 0000000000..97f957bc12
--- /dev/null
+++ b/static/examples/products/canonical/veo_generative_video_15s.json
@@ -0,0 +1,95 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "veo_generative_video_vertical_15s",
+  "name": "Veo — 15s Generative Vertical Video",
+  "description": "Generative video synthesis from a creative_brief plus structured video_brief. Buyer ships a brief (≤500 chars) and a video_brief (3 segments summing to 15s); Veo synthesizes the video. Genuinely nondeterministic — synthesis from in-spec inputs may produce out-of-spec frames; the platform's post-synthesis QA loop validates and reseeds up to N attempts before surfacing output. If the QA loop exhausts, build_creative returns task_failed with synthesis_failed reason. provenance_required: true means every produced asset carries a C2PA provenance manifest attributing synthesis to Veo (not the seller).",
+  "publisher_properties": [
+    {
+      "publisher_domain": "veo.example",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "social",
+    "olv"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpm_floor",
+      "pricing_model": "cpm",
+      "currency": "USD",
+      "floor_price": 18
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "UTC",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "clicks",
+      "spend",
+      "completion_rate",
+      "viewability"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "video_hosted",
+      "params": {
+        "orientation": "vertical",
+        "aspect_ratio": "9:16",
+        "duration_ms_exact": 15000,
+        "min_width": 1080,
+        "min_height": 1920,
+        "video_codecs": [
+          "h264"
+        ],
+        "containers": [
+          "mp4"
+        ],
+        "frame_rates": [
+          24,
+          30
+        ],
+        "asset_source": "agent_synthesized",
+        "buyer_asset_acceptance": "rejected",
+        "captions": "recommended",
+        "composition_model": "deterministic",
+        "synthesis_nondeterministic": true,
+        "provenance_required": true,
+        "production_window_business_days": 0,
+        "slots": [
+          {
+            "asset_group_id": "creative_brief",
+            "asset_type": "brief",
+            "required": true,
+            "max_chars": 500
+          },
+          {
+            "asset_group_id": "video_brief",
+            "asset_type": "object",
+            "required": true,
+            "min": 1,
+            "max": 5
+          },
+          {
+            "asset_group_id": "style_reference",
+            "asset_type": "image",
+            "required": false
+          },
+          {
+            "asset_group_id": "landing_page_url",
+            "asset_type": "url",
+            "required": false
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/examples/products/canonical/youtube_vast_preroll.json b/static/examples/products/canonical/youtube_vast_preroll.json
new file mode 100644
index 0000000000..cf9dfefc0f
--- /dev/null
+++ b/static/examples/products/canonical/youtube_vast_preroll.json
@@ -0,0 +1,94 @@
+{
+  "$schema": "/schemas/core/product.json",
+  "product_id": "youtube_vast_preroll_15s_skippable",
+  "name": "YouTube VAST Pre-roll (15s skippable, In-Stream)",
+  "description": "VAST tag pre-roll on YouTube In-Stream inventory, 16:9 horizontal, 5-second skippable threshold. Buyer ships a VAST 4.x tag (URL or inline XML); YouTube fires VAST events (impression / quartiles / click / complete / error / skip) inherent to the spec. VPAID 2.0 supported but discouraged \u2014 Google deprecates VPAID in 2026.",
+  "publisher_properties": [
+    {
+      "publisher_domain": "youtube.com",
+      "selection_type": "all"
+    }
+  ],
+  "channels": [
+    "olv",
+    "ctv"
+  ],
+  "delivery_type": "non_guaranteed",
+  "pricing_options": [
+    {
+      "pricing_option_id": "cpv_skippable",
+      "pricing_model": "cpv",
+      "currency": "USD",
+      "floor_price": 0.05,
+      "parameters": {
+        "view_threshold": {
+          "duration_seconds": 30
+        }
+      }
+    }
+  ],
+  "reporting_capabilities": {
+    "available_reporting_frequencies": [
+      "daily"
+    ],
+    "expected_delay_minutes": 240,
+    "timezone": "America/Los_Angeles",
+    "supports_webhooks": false,
+    "available_metrics": [
+      "impressions",
+      "completed_views",
+      "spend",
+      "completion_rate",
+      "viewability",
+      "quartile_data"
+    ],
+    "date_range_support": "date_range"
+  },
+  "format_options": [
+    {
+      "format_kind": "video_vast",
+      "v1_format_ref": [
+        {
+          "agent_url": "https://creative.adcontextprotocol.org/",
+          "id": "video_vast_30s"
+        }
+      ],
+      "params": {
+        "orientation": "horizontal",
+        "aspect_ratio": "16:9",
+        "vast_version": "4.2",
+        "vpaid_enabled": false,
+        "simid_supported": false,
+        "duration_ms_range": [
+          6000,
+          30000
+        ],
+        "min_width": 1280,
+        "min_height": 720,
+        "linear_required": true,
+        "skippable_after_ms": 5000,
+        "max_wrapper_depth": 5,
+        "ssl_required": true,
+        "composition_model": "deterministic",
+        "slots": [
+          {
+            "asset_group_id": "vast_tag",
+            "asset_type": "vast",
+            "required": true
+          },
+          {
+            "asset_group_id": "landing_page_url",
+            "asset_type": "url",
+            "required": false
+          }
+        ],
+        "platform_extensions": [
+          {
+            "uri": "https://creative.adcontextprotocol.org/translated/google/extensions/google_universal_ad_id",
+            "digest": "sha256:b3c5e7f9a1c3e5b7d9f1a3c5e7b9d1f3a5c7e9b1d3f5a7c9e1b3d5f7a9c1e3b5"
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/schemas/source/adagents.json b/static/schemas/source/adagents.json
index b25deff33f..a715d9a448 100644
--- a/static/schemas/source/adagents.json
+++ b/static/schemas/source/adagents.json
@@ -139,6 +139,39 @@
           },
           "minItems": 1
         },
+        "formats": {
+          "type": "array",
+          "description": "Publisher-authoritative format catalog. Declares the canonical-formats v2 shapes the publisher supports across its properties — the single place a publisher (or its community-registry stand-in) asserts \"these are the formats my inventory accepts.\" Products selling this publisher's inventory SHOULD reference these declarations by `capability_id` on the placement or via inline `format_options` whose `capability_id` matches an entry here, eliminating the N-copies-of-Meta-Reels-on-N-products drift surface.\n\nEach item is a `ProductFormatDeclaration` (same canonical-formats v2 shape used on Products) plus optional `applies_to_property_ids` / `applies_to_property_tags` for property scoping within the file. A `formats[]` entry without scope applies to all properties in the file; with scope, only to the named subset (e.g., Reels applies to Instagram + Facebook but not WhatsApp).\n\n**Community registry pattern (normative for unadopted platforms).** When a platform hasn't adopted AdCP (Meta, TikTok, Snap, Pinterest, etc.), AAO publishes a community-maintained adagents.json at `https://creative.adcontextprotocol.org/translated/<platform>/adagents.json` carrying that platform's `formats[]`. Buyer SDKs fetch the platform's own `<domain>/.well-known/adagents.json` first; on 404 or absence-of-formats[], they fall back to the AAO mirror. When the platform adopts AdCP and publishes their own adagents.json with `formats[]`, the platform-hosted file takes precedence and the mirror entry becomes redundant (AAO maintainers deprecate it).\n\nThe `v1_format_ref.agent_url` on each declaration SHOULD match the agent_url of the file's hosting location — platform-hosted formats point at the platform's agent, community-mirror formats point at `https://creative.adcontextprotocol.org/translated/<platform>`. This keeps the v1 namespace converged regardless of which side hosts the catalog. See `docs/creative/canonical-formats.mdx` Meta Reels worked example.",
+          "items": {
+            "allOf": [
+              { "$ref": "/schemas/core/product-format-declaration.json" },
+              {
+                "type": "object",
+                "properties": {
+                  "applies_to_property_ids": {
+                    "type": "array",
+                    "description": "Optional property IDs from this file's `properties[]` that this format declaration applies to. When omitted, the declaration applies to all properties in the file. Mutually compatible with `applies_to_property_tags` (union is the effective scope). Example: Meta declares Reels with `applies_to_property_ids: [\"instagram\", \"facebook\"]` because WhatsApp doesn't carry Reels inventory.",
+                    "items": { "$ref": "/schemas/core/property-id.json" },
+                    "minItems": 1
+                  },
+                  "applies_to_property_tags": {
+                    "type": "array",
+                    "description": "Optional property tags from this file's `tags` map that this format declaration applies to. When omitted, the declaration applies to all properties in the file. Useful for network-wide formats (e.g., a managed network declaring `applies_to_property_tags: [\"premium_video\"]`). Compatible with `applies_to_property_ids` — a property is in scope if it matches either ID list or tag list.",
+                    "items": { "$ref": "/schemas/core/property-tag.json" },
+                    "minItems": 1
+                  }
+                }
+              }
+            ]
+          },
+          "minItems": 1
+        },
+        "superseded_by": {
+          "type": "string",
+          "format": "uri",
+          "pattern": "^https://",
+          "description": "Optional pointer indicating this adagents.json file has been superseded by another adagents.json at a different URL. Used by the AAO community-mirror lifecycle: when a platform (e.g., Meta) adopts AdCP and publishes its own adagents.json at `<platform-domain>/.well-known/adagents.json`, the AAO mirror file at `creative.adcontextprotocol.org/translated/<platform>/adagents.json` sets `superseded_by` to the platform-hosted URL. Buyer SDKs encountering a file with `superseded_by` SHOULD short-circuit and re-fetch from the named URL rather than serving stale content from the mirror. The mirror SHOULD continue serving with `superseded_by` set for ≥1 minor release after platform adoption so buyer caches keyed on the mirror URL get an explicit migration signal rather than a silent break."
+        },
         "tags": {
           "type": "object",
           "description": "Metadata for each tag referenced by properties. Provides human-readable context for property tag values.",
diff --git a/static/schemas/source/core/asset-group-vocabulary.json b/static/schemas/source/core/asset-group-vocabulary.json
new file mode 100644
index 0000000000..798fea1549
--- /dev/null
+++ b/static/schemas/source/core/asset-group-vocabulary.json
@@ -0,0 +1,236 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/asset-group-vocabulary.json",
+  "title": "AdCP Asset Group Vocabulary Registry",
+  "description": "Canonical registry of asset_group_id values used in offering asset groups (OfferingAssetGroup) and in v2 product format declarations. Non-canonical IDs remain valid for platform-specific extensions; this registry codifies the recommended canonical set so that buyers and sellers share a vocabulary for the most common slot roles. Validators may emit soft warnings on non-canonical IDs to encourage convergence.\n\nThe registry covers everything the buyer ships in the manifest's `assets` map — both directly-rendered creative content (image, video, audio) AND content the seller consumes for production (script, creative_brief, video_brief). The seller dispatches per the format's slot declaration. There is no separate \"inputs\" map on the manifest; everything is an asset.\n\n**Two-tier boundary (normative).** This registry is the *canonical, portable* tier — IAB-aligned, platform-agnostic slot roles every adopter shares (`headline`, `body_text`, `main_image`, `cta`, `landing_page_url`, etc.). Platform-specific asset identifiers (e.g., YouTube video IDs, Pinterest pin IDs, TikTok video IDs, Snap attachment IDs, Meta Advantage+ creative IDs) MUST NOT be added here — they live on the canonical's `platform_extensions[]` (URI+digest reference to the platform's extension schema) so the canonical registry stays portable. Earlier drafts carried `youtube_video_id` and `pin_id` here; they were dropped in 3.1 GA precisely because adding them set precedent for every platform's identifier vocabulary to leak into the canonical tier, defeating the registry's portability purpose. Adopters needing to reference an existing platform-hosted asset attach a `platform_extensions[]` entry on the format declaration whose extension schema defines the platform-specific ID slot.",
+  "version": "1.1.0",
+  "lastUpdated": "2026-04-28",
+  "vocabulary": {
+    "headlines": {
+      "description": "Pool of headline text variants for the surface to choose from.",
+      "asset_type": "text",
+      "typical_use": "Multiple short headline copy variants (Google PMax/RDA, Meta promoted_offerings, etc.)",
+      "aliases": ["headline", "title", "tagline", "headline_text"]
+    },
+    "long_headlines": {
+      "description": "Pool of longer headline text variants (typically 60-90 chars) used by responsive formats that render in placements with more available text space.",
+      "asset_type": "text",
+      "typical_use": "Google Responsive Display Ads / Performance Max / Demand Gen — render alongside short `headlines` when the placement supports a longer headline string. Distinct from `headlines` (short, ≤30 chars typical).",
+      "aliases": ["long_headline_pool", "extended_headlines"]
+    },
+    "descriptions": {
+      "description": "Pool of body description text variants.",
+      "asset_type": "text",
+      "typical_use": "Body-copy variants for surfaces that pick the best combination.",
+      "aliases": ["description", "body", "body_text", "text", "content"]
+    },
+    "images_landscape": {
+      "description": "Pool of landscape-orientation images (1.91:1 or 16:9 typical).",
+      "asset_type": "image",
+      "typical_use": "Hero images for landscape-format placements (Meta feed, LinkedIn feed, Google display).",
+      "aliases": ["image", "hero_image", "landscape_image", "banner_image"]
+    },
+    "images_vertical": {
+      "description": "Pool of vertical-orientation images (9:16 typical).",
+      "asset_type": "image",
+      "typical_use": "Hero images for stories, reels, and other vertical placements (Snap, TikTok, Meta Stories, Pinterest).",
+      "aliases": ["vertical_image", "story_image", "portrait_image"]
+    },
+    "images_square": {
+      "description": "Pool of square-orientation images (1:1).",
+      "asset_type": "image",
+      "typical_use": "Feed-context images, profile-style placements, square carousel cards.",
+      "aliases": ["square_image", "feed_image"]
+    },
+    "logo": {
+      "description": "Brand logo asset (typically 1:1 or 2:1).",
+      "asset_type": "image",
+      "typical_use": "Brand attribution overlay (Google PMax/RDA, Snap Story Ad, Amazon SB).",
+      "aliases": ["brand_logo", "logo_image"]
+    },
+    "video": {
+      "description": "Pool of video assets.",
+      "asset_type": "video",
+      "typical_use": "Video creative for video placements; orientation determined by platform constraints.",
+      "aliases": ["video_file", "hero_video", "video_asset", "video_main"]
+    },
+    "video_vertical": {
+      "description": "Pool of vertical-orientation video (9:16).",
+      "asset_type": "video",
+      "typical_use": "Reels, Stories, TikTok In-Feed, Snap Spotlight, vertical short-form video."
+    },
+    "video_horizontal": {
+      "description": "Pool of horizontal-orientation video (16:9).",
+      "asset_type": "video",
+      "typical_use": "Pre-roll, mid-roll, instream, CTV, in-feed horizontal video."
+    },
+    "audio": {
+      "description": "Audio asset.",
+      "asset_type": "audio",
+      "typical_use": "Audio ads for streaming, podcasts, broadcast radio.",
+      "aliases": ["audio_file", "hero_audio", "audio_asset", "audio_main"]
+    },
+    "companion_image": {
+      "description": "Image displayed alongside an audio asset.",
+      "asset_type": "image",
+      "typical_use": "Brand-attribution image paired with audio (Spotify standard 640x640, Amazon DSP audio 300x300)."
+    },
+    "companion_banner": {
+      "description": "Banner image displayed alongside a video asset.",
+      "asset_type": "image",
+      "typical_use": "Companion banner for instream video (Google video 300x60, Amazon DSP 1.91:1)."
+    },
+    "brand_name": {
+      "description": "Short brand attribution text (distinct from headline).",
+      "asset_type": "text",
+      "typical_use": "Brand name overlay on Snap, TikTok, Spotify, Pinterest creative."
+    },
+    "body_text": {
+      "description": "Longer free-text body content.",
+      "asset_type": "text",
+      "typical_use": "Body copy on Reddit, Amazon DSP, LinkedIn formats — distinct from short headlines."
+    },
+    "cards": {
+      "description": "Per-item carousel card array.",
+      "asset_type": "object",
+      "typical_use": "Carousel slides on Meta, TikTok, Pinterest, LinkedIn, Reddit. Each card carries its own image/video, headline, and link.",
+      "aliases": ["carousel_cards", "slides", "carousel_items", "carousel_slides"]
+    },
+    "cta": {
+      "description": "Call-to-action button label or text.",
+      "asset_type": "text",
+      "typical_use": "CTA button on display/video/social ad creative (e.g., \"Shop Now\", \"Learn More\"). Most products narrow to a fixed enum via `cta_values`; this canonical entry names the slot itself.",
+      "aliases": ["cta_text", "call_to_action", "action_text", "button_text"]
+    },
+    "price": {
+      "description": "Product price slot rendered on the creative.",
+      "asset_type": "text",
+      "typical_use": "Pinterest shopping pins, Amazon Sponsored Brand product cards, retail-media catalog rendering, IAB OpenRTB Native 1.2 Data Asset type 6. Often pulled from a catalog field via `field_bindings`."
+    },
+    "display_url": {
+      "description": "Visible URL or domain string shown above/below the headline on native units (does not need to match the click destination).",
+      "asset_type": "text",
+      "typical_use": "Native in-feed and content-recommendation widgets (Taboola, Outbrain, Yahoo Native, AdMob Native). IAB OpenRTB Native 1.2 Data Asset type 11. The actual click destination lives on `landing_page_url`; `display_url` is presentation-only.",
+      "aliases": ["visible_url", "displayed_domain"]
+    },
+    "rating": {
+      "description": "Star or score rating rendered on the creative (e.g., \"4.5/5\", \"4.5 stars\").",
+      "asset_type": "text",
+      "typical_use": "App-install native units, product-rating native cards, review-style content-recommendation. IAB OpenRTB Native 1.2 Data Asset type 3."
+    },
+    "disclaimer": {
+      "description": "Required legal disclaimer or fine print.",
+      "asset_type": "text",
+      "typical_use": "Pharma, financial services, alcohol, sweepstakes — non-optional in regulated verticals. Receivers may render at reduced size below the primary creative.",
+      "aliases": ["legal_text", "fine_print", "legal_disclaimer"]
+    },
+    "phone_number": {
+      "description": "Phone number for click-to-call placements (E.164 preferred).",
+      "asset_type": "text",
+      "typical_use": "Google call-only ads, Bing call extensions, click-to-call retail/local placements."
+    },
+    "promo_code": {
+      "description": "Promotional / offer code rendered on the creative.",
+      "asset_type": "text",
+      "typical_use": "Retail / promo creative carrying a coupon code (e.g., \"SAVE20\"). Distinct from offering metadata; this is the rendered text.",
+      "aliases": ["offer_code", "coupon_code", "discount_code"]
+    },
+    "subtitle_file": {
+      "description": "Subtitle / closed-caption file for video assets.",
+      "asset_type": "url",
+      "typical_use": "WebVTT or SRT URL paired with a `video` slot. Required by accessibility-strict products; recommended for most video formats.",
+      "aliases": ["caption_file", "captions", "subtitles"]
+    },
+    "source_catalog": {
+      "description": "Catalog asset reference for catalog-driven products.",
+      "asset_type": "catalog",
+      "typical_use": "Required input on `sponsored_placement` formats. Buyer references a synced catalog by `catalog_id` plus optional item filters."
+    },
+    "hero_asset": {
+      "description": "Optional buyer-supplied hero/banner asset alongside a catalog reference.",
+      "asset_type": "image",
+      "typical_use": "Pinterest Collection, Snap Collection, Amazon SB Product Collection — buyer supplies a hero image; surface composes catalog tiles below it.",
+      "aliases": ["hero_banner", "collection_hero"]
+    },
+    "landing_page_url": {
+      "description": "Click-through destination URL for the ad.",
+      "asset_type": "url",
+      "typical_use": "Primary destination for ad click-through across all canonical formats.",
+      "aliases": [
+        "click_url",
+        "link",
+        "final_url",
+        "link_url",
+        "click_through_url",
+        "landing_url"
+      ],
+      "note": "Canonical name for the destination URL slot. Six different field names exist across platform format definitions today; adopters should standardize on `landing_page_url` for v2."
+    },
+    "privacy_policy_url": {
+      "description": "Privacy policy URL required for lead-form variants.",
+      "asset_type": "url",
+      "typical_use": "LinkedIn lead gen, Snap lead gen — required for any format that collects user data."
+    },
+    "impression_tracker": {
+      "description": "Renderer-fired impression tracker URL. Maps to `pixel_tracker` asset on any web-rendered canonical (image, html5, image_carousel, responsive_creative, sponsored_placement, native_*, plus non-VAST events on video_hosted/audio_hosted); maps to `url` asset with `url_type: \"tracker_pixel\"` on VAST/DAAST formats (per the VAST `<Impression>` boundary documented on vast_tracker).",
+      "asset_type": "pixel_tracker",
+      "typical_use": "Measurement vendor impression pixel that the seller's renderer fires at serve time. For VAST/DAAST formats use the url-asset shape instead.",
+      "aliases": ["imp_tracker", "impression_pixel", "imp_url"]
+    },
+    "click_tracker": {
+      "description": "Renderer-fired click tracker URL on native formats. Distinct from `landing_page_url` (the destination); click_tracker is a measurement hop that fires when the user clicks but doesn't navigate the user there.",
+      "asset_type": "pixel_tracker",
+      "typical_use": "IAB OpenRTB Native `link.clicktrackers[]` — measurement vendor URLs that fire on click in addition to the landing navigation.",
+      "aliases": ["click_pixel", "click_measurement_url"]
+    },
+    "viewability_tracker": {
+      "description": "Renderer-fired viewability tracker URL (MRC viewable, video-viewable). One per viewability event the buyer's measurement vendor wants to track.",
+      "asset_type": "pixel_tracker",
+      "typical_use": "MRC viewable measurement on any web-rendered format; the `pixel_tracker` event field carries the specific viewability variant (viewable_mrc_50, viewable_mrc_100, viewable_video_50, audible_video_complete)."
+    },
+    "script": {
+      "description": "Verbatim text the seller's production reads, dubs, or transforms into the rendered output.",
+      "asset_type": "text",
+      "typical_use": "Podcast host-read products (host reads buyer's script verbatim), TTS audio synthesis, video voiceover. Distinct from `creative_brief` (looser talking-points style guidance).",
+      "aliases": ["script_text", "host_script", "voiceover_script"]
+    },
+    "creative_brief": {
+      "description": "Talking points, brand context, and creative direction for seller-side or generative production.",
+      "asset_type": "brief",
+      "typical_use": "Generative AI products (text-to-image, text-to-video), brief-driven podcast host-reads (host has discretion within brief), creative-template platforms. Distinct from `script` (verbatim wording) — `creative_brief` gives the producer creative latitude.",
+      "aliases": ["brief", "creative_direction", "talking_points"]
+    },
+    "video_brief": {
+      "description": "Structured per-segment generation brief for generative video products.",
+      "asset_type": "object",
+      "typical_use": "Generative video products (Veo/Sora/Runway-class). Carries `segments[]` where each entry declares order, duration_ms, prompt, optional voiceover and caption. See /schemas/creative/video-brief.json for the typed structure. Distinct from `creative_brief` (free-form text); `video_brief` is the structured timed-prompt form.",
+      "aliases": ["scenes", "storyboard", "shot_brief"]
+    },
+    "voice_id": {
+      "description": "Voice selection from a format-defined enum or registered voice catalog.",
+      "asset_type": "text",
+      "typical_use": "TTS audio synthesis — buyer selects from the platform's voice library. The exact enum is per-format; the canonical name normalizes the slot key."
+    },
+    "offering_ref": {
+      "description": "Reference to a specific offering (product, service, campaign) within the buyer's brand catalog.",
+      "asset_type": "text",
+      "typical_use": "agent_placement products (focus the AI-surface mention on a specific offering); host-read products (specify which offering is being promoted in the read). Value is an offering_id matched against the buyer's catalog."
+    },
+    "style_reference": {
+      "description": "Reference asset (image) providing per-creative visual style guidance for generative production. Distinct from brand.json — brand.json carries declarative brand-level style (hex colors, voice descriptions, logo asset, tagline) that's stable across campaigns; `style_reference` carries a per-creative reference image (\"make it look like THIS\") that ships in the manifest. For pure brand-style consistency, the manifest's BrandRef resolving brand.json suffices and `style_reference` isn't needed.",
+      "asset_type": "image",
+      "typical_use": "Image-to-image variation (MidJourney --sref, Adobe Firefly structure/style reference), style transfer, reusing a hero shot's lighting/composition for new creative. Buyer supplies a reference image; seller's generative pipeline produces output matching the visual style.",
+      "aliases": ["reference_image", "style_image", "inspiration_image", "structure_reference"]
+    },
+    "starter_assets": {
+      "description": "Pool of reference assets the seller uses as a starting point for transformation or variation.",
+      "asset_type": "object",
+      "typical_use": "Generative platforms that take an existing creative and produce variations (different sizes, orientations, durations). Buyer supplies the starter; seller derives outputs."
+    }
+  },
+  "governance": {
+    "extension_policy": "Non-canonical asset_group_id values remain valid for platform-specific extensions. Validators may emit soft warnings to encourage adoption of canonical values where applicable. New canonical entries are added via PR with rationale, at least one reference adopter, and AAO maintainer review.",
+    "alias_policy": "Aliases listed for canonical entries (e.g., `landing_page_url` aliases) are recognized as v1-era variants. v2 adopters should standardize on the canonical name; v1 aliases continue to work for backwards compatibility.",
+    "versioning": "This registry is versioned independently of the AdCP spec. Bump `version` on any addition or alias change; preserve existing canonical entries to avoid breaking adopters that have standardized on them."
+  }
+}
diff --git a/static/schemas/source/core/assets/asset-union.json b/static/schemas/source/core/assets/asset-union.json
index a5480b58c2..552544e6c2 100644
--- a/static/schemas/source/core/assets/asset-union.json
+++ b/static/schemas/source/core/assets/asset-union.json
@@ -12,12 +12,14 @@
     { "$ref": "/schemas/core/assets/url-asset.json" },
     { "$ref": "/schemas/core/assets/html-asset.json" },
     { "$ref": "/schemas/core/assets/javascript-asset.json" },
+    { "$ref": "/schemas/core/assets/zip-asset.json" },
     { "$ref": "/schemas/core/assets/webhook-asset.json" },
     { "$ref": "/schemas/core/assets/css-asset.json" },
     { "$ref": "/schemas/core/assets/daast-asset.json" },
     { "$ref": "/schemas/core/assets/markdown-asset.json" },
     { "$ref": "/schemas/core/assets/brief-asset.json" },
-    { "$ref": "/schemas/core/assets/catalog-asset.json" }
+    { "$ref": "/schemas/core/assets/catalog-asset.json" },
+    { "$ref": "/schemas/core/assets/card-asset.json" }
   ],
   "discriminator": {
     "propertyName": "asset_type"
diff --git a/static/schemas/source/core/assets/card-asset.json b/static/schemas/source/core/assets/card-asset.json
new file mode 100644
index 0000000000..4fb3d16ffb
--- /dev/null
+++ b/static/schemas/source/core/assets/card-asset.json
@@ -0,0 +1,49 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/assets/card-asset.json",
+  "title": "Card Asset",
+  "description": "A single card in a multi-card creative (image_carousel, future composed carousels). Carries: `media` (an image OR video asset), optional `headline` (short text), optional `description` (longer text), optional `cta` (call-to-action label), optional `landing_page_url` (url asset with `url_type: \"clickthrough\"`).\n\nCovers the multi-card patterns across Meta carousel, Pinterest sponsored pin, Snap Collection, TikTok carousel, and AI-surface result cards. The two-field text shape (`headline` + `description`) reflects how almost every adopter splits short labels from longer copy; Pinterest pin description and Meta per-card description both go in `description`.\n\nUsed as the array element type for the `cards` slot on image_carousel canonicals. Adopters MUST NOT invent per-card key conventions like `card_0_headline` / `cards.0.headline` — the manifest's `assets.cards` value is an array of card-asset objects, period. Per-card platform extensions (e.g., Meta-specific carousel attributes, Pinterest rich-pin metadata, Snap Collection price tags) attach via the `platform_extensions` field, never via inline non-canonical keys.",
+  "type": "object",
+  "required": ["asset_type", "media"],
+  "properties": {
+    "asset_type": {
+      "type": "string",
+      "const": "card",
+      "description": "Discriminator identifying this as a card asset. See /schemas/creative/asset-types for the registry."
+    },
+    "media": {
+      "description": "The card's primary visual asset. Either an `image` or `video` asset, matching the parent format's `allowed_card_media_asset_types` parameter.",
+      "oneOf": [
+        { "$ref": "/schemas/core/assets/image-asset.json" },
+        { "$ref": "/schemas/core/assets/video-asset.json" }
+      ],
+      "discriminator": { "propertyName": "asset_type" }
+    },
+    "headline": {
+      "type": "string",
+      "description": "Optional per-card short text label (typically 25-40 chars). Length governed by `card_headline_max_chars` on the format declaration. Meta carousel headline, Pinterest pin title, Snap Collection sticker text, TikTok caption-short."
+    },
+    "description": {
+      "type": "string",
+      "description": "Optional per-card longer text (typically 100-500 chars). Distinct from `headline`: `description` is body copy, `headline` is the label. Length governed by `card_description_max_chars` on the format declaration. Meta carousel description, Pinterest pin description, AI-surface result body text, TikTok long caption."
+    },
+    "cta": {
+      "type": "string",
+      "description": "Optional per-card call-to-action label (e.g., 'SHOP_NOW', 'LEARN_MORE'). When the parent format declares `cta_values` (allowed CTA labels), the per-card `cta` MUST be one of those values. Lets a Meta or TikTok carousel show different CTAs per card."
+    },
+    "landing_page_url": {
+      "$ref": "/schemas/core/assets/url-asset.json",
+      "description": "Optional per-card click-through URL. URL asset with `url_type: \"clickthrough\"`."
+    },
+    "platform_extensions": {
+      "type": "array",
+      "description": "Per-card platform-specific extensions (URI+digest references). Same hosting model as format-level platform_extensions. Use this for Meta carousel-card attributes, Pinterest pin overrides, etc. — NEVER inline non-canonical keys on the card object directly.",
+      "items": { "$ref": "/schemas/core/platform-extension-ref.json" }
+    },
+    "provenance": {
+      "$ref": "/schemas/core/provenance.json",
+      "description": "Provenance metadata for this card, overrides manifest-level provenance."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/core/assets/html-asset.json b/static/schemas/source/core/assets/html-asset.json
index e28a47d581..76b89e6f4a 100644
--- a/static/schemas/source/core/assets/html-asset.json
+++ b/static/schemas/source/core/assets/html-asset.json
@@ -2,7 +2,7 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "/schemas/core/assets/html-asset.json",
   "title": "HTML Asset",
-  "description": "HTML content asset",
+  "description": "Inline HTML content asset. For URL-delivered HTML5 banner bundles, use the zip asset type instead. For single-URL iframe-rendered tag references, use the url asset type with an appropriate url_type.",
   "type": "object",
   "properties": {
     "asset_type": {
diff --git a/static/schemas/source/core/assets/javascript-asset.json b/static/schemas/source/core/assets/javascript-asset.json
index 0af6b3adb7..9b1522c7ad 100644
--- a/static/schemas/source/core/assets/javascript-asset.json
+++ b/static/schemas/source/core/assets/javascript-asset.json
@@ -2,7 +2,7 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "/schemas/core/assets/javascript-asset.json",
   "title": "JavaScript Asset",
-  "description": "JavaScript code asset",
+  "description": "Inline JavaScript content asset. For URL-delivered third-party tag scripts, use the url asset type with url_type 'tracker_script'. For HTML5 banner bundles that include JavaScript, use the zip asset type.",
   "type": "object",
   "properties": {
     "asset_type": {
diff --git a/static/schemas/source/core/assets/pixel-tracker-asset.json b/static/schemas/source/core/assets/pixel-tracker-asset.json
new file mode 100644
index 0000000000..48b4fc0f6e
--- /dev/null
+++ b/static/schemas/source/core/assets/pixel-tracker-asset.json
@@ -0,0 +1,105 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/assets/pixel-tracker-asset.json",
+  "title": "Pixel Tracker Asset",
+  "description": "A single renderer-fired HTTP tracker URL — image pixel or JavaScript include — bound to a measurement event (impression, viewability, click, custom). Generic web-pixel tracker primitive applicable to any web-rendered canonical format (image, html5, image_carousel, responsive_creative, sponsored_placement, native_*, plus the non-VAST/DAAST events of video_hosted and audio_hosted). The buyer's measurement vendor declares the tracker URL; the seller's renderer fires it at serve time without buyer-side involvement.\n\nThe discriminated-union shape and event/method enums are formalized in IAB OpenRTB Native 1.2 (`imptrackers[]` / `jstracker` / `eventtrackers[]` / `link.clicktrackers[]`); the same shape applies cleanly to image banners, html5, carousels, and any other format whose renderer fires HTTP pixels for measurement. The name `pixel_tracker` mirrors the industry's existing 'tracker pixel' terminology (already used in `url_type: \"tracker_pixel\"`) and applies equally to `method: img` and `method: js` (a JS include is still a measurement-pixel hop in vendor parlance).\n\n**Scope boundary (normative).** `pixel_tracker` covers RENDERER-FIRED trackers — measurement events that the ad's serving template invokes when the user sees, views, or clicks the creative. Conversion pixels that fire on the advertiser's site after the click (Meta Pixel, GA4 server-side, custom postbacks) MUST be modeled via `sync_event_sources` / `event_log` — they are campaign-scoped, not creative-asset-scoped. See `docs/creative/canonical-formats.mdx#what-format_kind-is-not-for`.\n\n**Format-specific tracker primitives.** Formats whose wire shape embeds tracker URLs in a format-specific structure use dedicated asset types instead:\n- `video_vast` → `vast_tracker` (VAST `<TrackingEvents>`: start, quartiles, complete, pause, mute)\n- `audio_daast` → `daast_tracker` (DAAST `<TrackingEvents>` parity)\n- `display_tag` → opaque (third-party server fires its own trackers)\n\nAll other web-rendered canonicals use `pixel_tracker`.\n\nMaps to IAB OpenRTB Native 1.2 / Dynamic Native Ads API tracker objects:\n- `imptrackers[]` → one `pixel_tracker` per entry with `event: impression`, `method: img`\n- `jstracker` → one `pixel_tracker` with `event: impression`, `method: js`\n- `eventtrackers[]` → one `pixel_tracker` per entry, `event` mapped from the IAB event enum\n- `link.clicktrackers[]` → one `pixel_tracker` per entry with `event: click`, `method: img` (click destinations live on `landing_page_url` slot)\n\n**Bidirectional v1↔v2 mapping (normative for SDK auto-negotiation).** A 3.1 buyer SDK talking to a 3.0.x seller MUST downgrade `pixel_tracker` to the v1 `{asset_type: url, url_type: tracker_pixel}` shape. The URL still emits on the wire; what's lost depends on the original event/method. A 3.1 SDK reading a v1 manifest MUST upgrade `{asset_type: url, url_type: tracker_pixel}` to `pixel_tracker` by inferring event/method from the v1 `asset_id`. Both directions are lossy-with-advisory; SDKs MUST emit the appropriate error code so consumers can see what was inferred or dropped.\n\n**v2 → v1 downgrade table:**\n| pixel_tracker source | v1 emit | Lost fields | Error code |\n|---|---|---|---|\n| `{event: impression, method: img, url}` | `{url_type: tracker_pixel, asset_id: impression_tracker, url}` | none | (no advisory) |\n| `{event: viewable_mrc_50, method: img, url}` | `{url_type: tracker_pixel, asset_id: viewability_tracker, url}` | event variant | `PIXEL_TRACKER_LOSSY_DOWNGRADE` |\n| `{event: viewable_mrc_100, method: img, url}` | same shape | event variant | `PIXEL_TRACKER_LOSSY_DOWNGRADE` |\n| `{event: viewable_video_50, method: img, url}` | same shape | event variant | `PIXEL_TRACKER_LOSSY_DOWNGRADE` |\n| `{event: audible_video_complete, method: img, url}` | same shape | event variant | `PIXEL_TRACKER_LOSSY_DOWNGRADE` |\n| `{event: click, method: img, url}` | `{url_type: tracker_pixel, asset_id: click_tracker, url}` | none meaningful | (no advisory) |\n| `{event: custom, custom_event_name: X, ...}` | `{url_type: tracker_pixel, asset_id: impression_tracker, url}` (defaults to impression timing) | custom event timing | `PIXEL_TRACKER_LOSSY_DOWNGRADE` |\n| `{method: js, any event, url}` | same shape with `url_type: tracker_pixel` | JS execution context — URL is hit via GET (counter increments), but JS body doesn't execute (OMID-style verification, viewability observers, cross-domain cookie setters won't fire) | `PIXEL_TRACKER_LOSSY_DOWNGRADE` |\n\n**v1 → v2 upgrade table (inferred — SDK has no explicit event/method):**\n| v1 source (asset_id) | Inferred pixel_tracker | Inference basis |\n|---|---|---|\n| `impression_tracker` | `{event: impression, method: img}` | asset_id convention |\n| `viewability_tracker` | `{event: viewable_mrc_50, method: img}` | asset_id convention + most-common default (50% is the dominant variant in v1 catalogs) |\n| `click_tracker` | `{event: click, method: img}` | asset_id convention |\n| `<other asset_id>` | `{event: custom, custom_event_name: <original asset_id>, method: img}` | fallback — preserves the original asset_id as the custom name |\n\nAll v1→v2 upgrades surface `PIXEL_TRACKER_UPGRADE_INFERRED` so consumers can see that event/method were inferred rather than explicitly declared.",
+  "type": "object",
+  "properties": {
+    "asset_type": {
+      "type": "string",
+      "const": "pixel_tracker",
+      "description": "Discriminator identifying this as a renderer-fired pixel tracker asset. See /schemas/creative/asset-types for the registry."
+    },
+    "event": {
+      "type": "string",
+      "enum": [
+        "impression",
+        "viewable_mrc_50",
+        "viewable_mrc_100",
+        "viewable_video_50",
+        "audible_video_complete",
+        "click",
+        "custom"
+      ],
+      "description": "Which event this tracker fires on. Event enum mirrors IAB OpenRTB Native 1.2 event-tracker registry (event types 1, 2, 3, 4, 500); the events themselves are generic web-pixel measurement events that apply to any renderer:\n- `impression` (IAB type 1) — fires when the ad is served. Covers both `imptrackers[]` and `jstracker` from the IAB shape, distinguished by `method`.\n- `viewable_mrc_50` (IAB type 2) — IAB MRC viewable, 50% pixels for ≥1 second.\n- `viewable_mrc_100` (IAB type 3) — IAB MRC viewable, 100% pixels for ≥1 second.\n- `viewable_video_50` (IAB type 4) — video-specific viewable, 50% pixels for ≥2 seconds with audio on. On video_hosted; ignored on image/html5.\n- `audible_video_complete` (IAB type 500) — video reached 100% completion with audio on. Distinct from `viewable_video_50` (50% pixels + 2s threshold) — this is the full-completion audible-view event. Meaningful on non-VAST video formats (Meta Reels, YouTube Shorts, TikTok Spark) where audible-complete is a measured event but VAST `<TrackingEvents>` isn't the wire format; VAST formats use `vast_tracker` with `vast_event: complete` plus a separate audible tracker instead.\n- `click` — fires when the user clicks the creative (`link.clicktrackers[]`).\n- `custom` — adopter-defined event for anything not in the standardized enum. MUST also set `custom_event_name`. Reserved for IAB Native event types 555+ (exchange-specific) and any vendor-defined event not yet promoted to a first-class enum value."
+    },
+    "method": {
+      "type": "string",
+      "enum": ["img", "js"],
+      "default": "img",
+      "description": "How the tracker URL is invoked at serve time:\n- `img` — fired as an image pixel (HTTP GET with `<img>`-like semantics; no JS execution)\n- `js` — fired as a script include (renderer evaluates the URL's response as JavaScript)\n\nMatches IAB OpenRTB Native 1.2 method enum (1=img, 2=js). `js` MUST only be used by sellers whose renderer supports JavaScript trackers; sellers without JS-tracker support MUST reject `method: js` declarations at sync_creatives time with `CREATIVE_REJECTED` carrying the reason."
+    },
+    "url": {
+      "type": "string",
+      "format": "uri-template",
+      "description": "Tracker URL fired when `event` occurs. May carry AdCP universal macros (e.g., `{MEDIA_BUY_ID}`, `{CREATIVE_ID}`, `{CACHEBUSTER}`); the seller's renderer URL-encodes substituted values at serve time. See docs/creative/universal-macros.mdx."
+    },
+    "custom_event_name": {
+      "type": "string",
+      "description": "REQUIRED when `event` is `custom`; otherwise MUST be absent. Adopter-defined event name. Sellers without registered handling for a given custom_event_name MUST silently no-op (do not fire) rather than reject — custom events are forward-compatible probes."
+    },
+    "provenance": {
+      "$ref": "/schemas/core/provenance.json",
+      "description": "Provenance metadata for this asset, overrides manifest-level provenance."
+    }
+  },
+  "required": [
+    "asset_type",
+    "event",
+    "url"
+  ],
+  "allOf": [
+    {
+      "if": {
+        "properties": { "event": { "const": "custom" } },
+        "required": ["event"]
+      },
+      "then": {
+        "required": ["custom_event_name"]
+      },
+      "else": {
+        "not": { "required": ["custom_event_name"] }
+      }
+    }
+  ],
+  "additionalProperties": true,
+  "examples": [
+    {
+      "asset_type": "pixel_tracker",
+      "event": "impression",
+      "method": "img",
+      "url": "https://measurement.example.com/imp?cb={CACHEBUSTER}&cid={CREATIVE_ID}"
+    },
+    {
+      "asset_type": "pixel_tracker",
+      "event": "impression",
+      "method": "js",
+      "url": "https://measurement.example.com/jstracker.js?cid={CREATIVE_ID}"
+    },
+    {
+      "asset_type": "pixel_tracker",
+      "event": "viewable_mrc_50",
+      "method": "img",
+      "url": "https://measurement.example.com/mrc50?cid={CREATIVE_ID}"
+    },
+    {
+      "asset_type": "pixel_tracker",
+      "event": "click",
+      "method": "img",
+      "url": "https://measurement.example.com/click?cid={CREATIVE_ID}&cb={CACHEBUSTER}"
+    },
+    {
+      "asset_type": "pixel_tracker",
+      "event": "audible_video_complete",
+      "method": "img",
+      "url": "https://measurement.example.com/audible_complete?cid={CREATIVE_ID}"
+    },
+    {
+      "asset_type": "pixel_tracker",
+      "event": "custom",
+      "custom_event_name": "engagement_3s",
+      "method": "img",
+      "url": "https://measurement.example.com/engagement?cid={CREATIVE_ID}&duration=3s"
+    }
+  ]
+}
diff --git a/static/schemas/source/core/assets/zip-asset.json b/static/schemas/source/core/assets/zip-asset.json
new file mode 100644
index 0000000000..9a7f1ca2dc
--- /dev/null
+++ b/static/schemas/source/core/assets/zip-asset.json
@@ -0,0 +1,89 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/assets/zip-asset.json",
+  "title": "Zip Asset",
+  "description": "Bundled creative asset delivered as a zip archive — typically an HTML5 banner with index.html plus supporting CSS, JS, images, and fonts. Receivers unpack the zip, validate internal structure, and serve contents from CDN. Distinct from inline HTML (html asset) and from third-party tag URLs (url asset with url_type tracker_script).",
+  "type": "object",
+  "properties": {
+    "asset_type": {
+      "type": "string",
+      "const": "zip",
+      "description": "Discriminator identifying this as a zip-bundled asset. See /schemas/creative/asset-types for the registry."
+    },
+    "url": {
+      "type": "string",
+      "format": "uri",
+      "description": "URL where the zip archive is hosted. Must be HTTPS."
+    },
+    "max_file_size_kb": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "Maximum file size in kilobytes. Receivers should reject zips exceeding this."
+    },
+    "entry_point": {
+      "type": "string",
+      "description": "Relative path to the entry file within the zip (typically 'index.html'). Receivers default to 'index.html' if absent."
+    },
+    "allowed_inner_extensions": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "File extensions permitted inside the zip (e.g., ['html', 'css', 'js', 'png', 'jpg', 'svg', 'webp', 'json', 'woff2']). Receivers may reject zips containing other extensions."
+    },
+    "backup_image_url": {
+      "type": "string",
+      "format": "uri",
+      "description": "Fallback image URL for environments that cannot render the bundled creative (e.g., non-HTML5 endpoints, ad blockers). Recommended for HTML5 banners."
+    },
+    "digest": {
+      "type": "string",
+      "pattern": "^sha256:[a-f0-9]{64}$",
+      "description": "Optional SHA-256 content digest of the zip archive (sha256:<hex>) for integrity verification. Lets receivers detect tampered or stale archives."
+    },
+    "accessibility": {
+      "type": "object",
+      "description": "Self-declared accessibility properties for this opaque creative",
+      "x-accessibility": true,
+      "properties": {
+        "alt_text": {
+          "type": "string",
+          "description": "Text alternative describing the creative content"
+        },
+        "keyboard_navigable": {
+          "type": "boolean",
+          "description": "Whether the creative can be fully operated via keyboard"
+        },
+        "motion_control": {
+          "type": "boolean",
+          "description": "Whether the creative respects prefers-reduced-motion or provides pause/stop controls"
+        },
+        "screen_reader_tested": {
+          "type": "boolean",
+          "description": "Whether the creative has been tested with screen readers"
+        }
+      }
+    },
+    "provenance": {
+      "$ref": "/schemas/core/provenance.json",
+      "description": "Provenance metadata for this asset, overrides manifest-level provenance"
+    }
+  },
+  "required": [
+    "asset_type",
+    "url"
+  ],
+  "additionalProperties": true,
+  "examples": [
+    {
+      "description": "HTML5 banner bundle with backup image",
+      "data": {
+        "asset_type": "zip",
+        "url": "https://cdn.acme.example/creatives/spring-300x250-html5.zip",
+        "max_file_size_kb": 200,
+        "entry_point": "index.html",
+        "allowed_inner_extensions": ["html", "css", "js", "png", "jpg", "svg", "json"],
+        "backup_image_url": "https://cdn.acme.example/creatives/spring-300x250-backup.jpg",
+        "digest": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+      }
+    }
+  ]
+}
diff --git a/static/schemas/source/core/brand-ref.json b/static/schemas/source/core/brand-ref.json
index 16a686a2a3..a56e2440d1 100644
--- a/static/schemas/source/core/brand-ref.json
+++ b/static/schemas/source/core/brand-ref.json
@@ -32,6 +32,35 @@
         { "required": ["email"] }
       ],
       "additionalProperties": false
+    },
+    "brand_kit_override": {
+      "type": "object",
+      "description": "Inline override for brand-kit fields normally resolved from `/.well-known/brand.json` on `domain` (logo, colors, voice, tagline). Use when brand.json is missing, stale, or inappropriate for this specific call — e.g., a campaign-scoped tagline, a co-branded creative, a freshly-rebranded color palette the brand.json hasn't shipped yet. Same inline-override pattern as `industries` and `data_subject_contestation` above: brand.json is canonical, the override is per-call. Adopters needing to override fields outside this subset (`voice_attributes`, `prohibited_terms`, etc.) MUST publish a different brand.json and reference it via a different `domain` — the inline override is intentionally narrow to a small high-traffic subset.\n\n**Merge semantics (normative).** The merge is **field-level**, not whole-object replacement. Each field within `brand_kit_override` (`logo`, `colors`, `voice`, `tagline`) is evaluated independently — when a field is present on the override the override value applies; when a field is absent the brand.json value applies (or is absent if brand.json doesn't carry one either). For composite fields (`colors.primary`, `colors.secondary`, `colors.accent`), the merge is one level deeper: each color slot is evaluated independently — a producer can override `colors.primary` while still inheriting `colors.secondary` from brand.json. SDKs MUST NOT treat a present `brand_kit_override.colors` as wiping the brand.json `colors` block entirely; only the per-slot fields present in the override take precedence. Without this rule, a partial-override semantics would diverge across SDKs and produce inconsistent rendering for the same payload.",
+      "properties": {
+        "logo": {
+          "$ref": "/schemas/core/assets/image-asset.json",
+          "description": "Override logo asset."
+        },
+        "colors": {
+          "type": "object",
+          "description": "Override brand colors (hex strings).",
+          "properties": {
+            "primary": { "type": "string", "pattern": "^#[0-9a-fA-F]{6}$" },
+            "secondary": { "type": "string", "pattern": "^#[0-9a-fA-F]{6}$" },
+            "accent": { "type": "string", "pattern": "^#[0-9a-fA-F]{6}$" }
+          },
+          "additionalProperties": true
+        },
+        "voice": {
+          "type": "string",
+          "description": "Override brand-voice description for surface-composed text/audio output."
+        },
+        "tagline": {
+          "type": "string",
+          "description": "Override tagline."
+        }
+      },
+      "additionalProperties": true
     }
   },
   "required": ["domain"],
diff --git a/static/schemas/source/core/canonical-format-kind.json b/static/schemas/source/core/canonical-format-kind.json
new file mode 100644
index 0000000000..f9a43c74fb
--- /dev/null
+++ b/static/schemas/source/core/canonical-format-kind.json
@@ -0,0 +1,22 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/canonical-format-kind.json",
+  "title": "Canonical Format Kind",
+  "description": "Discriminator value naming one of the 12 canonical creative formats — plus `custom` for adopter-defined shapes that don't fit the canonicals (multi-placement takeover, roadblock, branded content, cross-screen sponsorship, AR lens, etc.). Used by `product-format-declaration.json` (the product's inline format declaration), `creative-manifest.json` (the buyer's v2 manifest path), and any other surface that needs to identify which canonical a payload targets.\n\nWhen `format_kind: \"custom\"`, the declaration MUST also carry `format_shape` (referencing the [format-shape vocabulary registry](/schemas/core/format-shape-vocabulary.json) — recognized global pattern this custom shape is an instance of) and `format_schema` (URI+digest reference to a fetchable schema describing the shape's actual `params` and `slots`). Buyer agents fetch the schema, validate manifests structurally, and reason about manifests without per-seller integration code — same mechanic as `platform_extensions`. See [adcp#3666](https://github.com/adcontextprotocol/adcp/issues/3666) for the canonical promotion queue.\n\nThe canonical enum mirrors the `oneOf` branches in `product-format-declaration.json`; keep them in sync.\n\n**Open-enum semantics (normative).** The enum list above is the AdCP 3.1 baseline. New canonical formats promoted from `format_shape` entries (see [#3666](https://github.com/adcontextprotocol/adcp/issues/3666)) extend this enum in subsequent minor releases — adding a value is non-breaking by design. Consumer SDKs MUST treat this enum as **open** at parse time: an unknown `format_kind` value MUST be retained as-is on the in-memory object (not silently dropped or rewritten to `\"custom\"`) and MUST NOT cause the surrounding payload to fail validation. Buyers reading a declaration with an unknown `format_kind` SHOULD treat the declaration as `runtime_status: declared_only` for routing purposes (filter out of default product views; opt-in to surface) so adopters on older SDK versions don't crash on newer canonical values, and adopters on newer SDK versions get a graceful unknown-value handling story. The producer-side enum stays closed (sellers MUST NOT mint ad-hoc `format_kind` values — use `format_kind: \"custom\"` with `format_shape` + `format_schema` for non-registered shapes); the consumer-side enum stays open for forward compatibility.",
+  "type": "string",
+  "enum": [
+    "image",
+    "html5",
+    "display_tag",
+    "image_carousel",
+    "video_hosted",
+    "video_vast",
+    "audio_hosted",
+    "audio_daast",
+    "sponsored_placement",
+    "native_in_feed",
+    "responsive_creative",
+    "agent_placement",
+    "custom"
+  ]
+}
diff --git a/static/schemas/source/core/canonical-projection-ref.json b/static/schemas/source/core/canonical-projection-ref.json
new file mode 100644
index 0000000000..6db4d999b1
--- /dev/null
+++ b/static/schemas/source/core/canonical-projection-ref.json
@@ -0,0 +1,74 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/canonical-projection-ref.json",
+  "title": "Canonical Projection Reference",
+  "description": "Authoritative v1 → v2 projection annotation on a v1 named format. Tells SDKs which canonical-formats v2 declaration to produce when projecting this v1 format to v2, including any non-default `asset_source` and slot-override hints needed when the v1 format's asset shape doesn't follow the canonical's defaults.\n\n**Why an object, not just a string.** A bare-string annotation like `canonical: \"image\"` carries the canonical's default slot shape (image_main: image, required) and default asset_source (buyer_uploaded). For v1 formats that genuinely follow those defaults (e.g., a 300×250 image upload), that's correct. For v1 formats whose asset shape differs (e.g., a generative entry whose input is `generation_prompt: text`, not an image upload), a bare-string annotation is lossy — the projected v2 declaration would claim buyer-uploaded image bytes when the underlying inventory wants a text prompt. The object form lets the catalog carry the asset_source + slot override so projection is lossless.\n\n**SDK projection rules (normative).**\n1. Read `kind` — this becomes `format_kind` on the projected v2 ProductFormatDeclaration.\n2. If `asset_source` is set, copy to the projected declaration's `params.asset_source`. If absent, projection uses the canonical's default asset_source (typically `buyer_uploaded`).\n3. If `slots_override` is set, copy to the projected declaration's `params.slots[]`, REPLACING the canonical's default slot set. If absent, projection inherits the canonical's defaults.\n4. v1 format's `requirements` (dimensions, durations, codecs, etc.) become `params` fields on the projected declaration per the canonical's parameter schema.\n5. v1 format's `assets[*]` shape MUST be consistent with the resulting `slots[]` — the v1 assets are the projected slots, just identified by `asset_id` (v1) ↔ `asset_group_id` (v2). The asset-group-vocabulary registry resolves aliases.\n\n**Examples.**\n\nDefault-slot case (a 300×250 image upload format):\n```json\n\"canonical\": { \"kind\": \"image\" }\n```\nGenerative case (a 300×250 entry whose input is a text prompt):\n```json\n\"canonical\": {\n  \"kind\": \"image\",\n  \"asset_source\": \"agent_synthesized\",\n  \"slots_override\": [\n    { \"asset_group_id\": \"generation_prompt\", \"asset_type\": \"text\", \"required\": true }\n  ]\n}\n```\nBoth project to `format_kind: \"image\"` — the difference is the per-product `asset_source` + `slots[]` shape. v2-aware buyers see the projection and know whether to ship image bytes or a text prompt.",
+  "type": "object",
+  "required": ["kind"],
+  "properties": {
+    "kind": {
+      "$ref": "/schemas/core/canonical-format-kind.json",
+      "description": "The v2 canonical-format-kind this v1 format projects to (`image`, `html5`, `display_tag`, `image_carousel`, `video_hosted`, `video_vast`, `audio_hosted`, `audio_daast`, `sponsored_placement`, `responsive_creative`, `agent_placement`, or `custom`)."
+    },
+    "asset_source": {
+      "type": "string",
+      "enum": ["buyer_uploaded", "publisher_host_recorded", "seller_pre_rendered_from_brief", "seller_human_designed", "agent_synthesized"],
+      "description": "Where the rendered asset bytes come from on the projected v2 declaration. Default (when omitted) is `buyer_uploaded` — the canonical's default. Set explicitly when the v1 named format doesn't follow that default. Required for generative entries (`agent_synthesized` or `seller_pre_rendered_from_brief`) because their asset shape doesn't carry image/video/audio bytes — projection without this hint produces a lossy v2 declaration that claims buyer-uploaded bytes."
+    },
+    "slots_override": {
+      "type": "array",
+      "minItems": 1,
+      "description": "When the v1 named format's slot shape differs from the canonical's default slots, this carries the override that the projected v2 declaration's `params.slots[]` should use. REPLACES (does not merge with) the canonical's default slots — projection-time semantics. The slot vocabulary follows `asset-group-vocabulary.json`. Asset IDs in the v1 format's `assets[*]` MUST resolve (directly or via the vocabulary's aliases) to the `asset_group_id` values declared here.",
+      "items": {
+        "type": "object",
+        "required": ["asset_group_id", "asset_type"],
+        "properties": {
+          "asset_group_id": {
+            "type": "string",
+            "description": "Asset group identifier from `asset-group-vocabulary.json` (e.g., `generation_prompt`, `creative_brief`, `image_main`, `video_main`)."
+          },
+          "asset_type": {
+            "type": "string",
+            "description": "Asset type — `image`, `video`, `audio`, `text`, `html`, `javascript`, `url`, `zip`, `brief`."
+          },
+          "required": {
+            "type": "boolean",
+            "default": false,
+            "description": "Whether the slot is required in the projected declaration."
+          },
+          "max_chars": {
+            "type": "integer",
+            "minimum": 1,
+            "description": "Max character count for text slots."
+          },
+          "consumed_for_production": {
+            "type": "boolean",
+            "default": true,
+            "description": "When false, slot is for moderation/review only and is NOT consumed by the seller's renderer (e.g., a brand-safety brief that informs review but doesn't appear in the rendered ad)."
+          }
+        },
+        "additionalProperties": true
+      }
+    }
+  },
+  "additionalProperties": true,
+  "examples": [
+    {
+      "kind": "image"
+    },
+    {
+      "kind": "image",
+      "asset_source": "agent_synthesized",
+      "slots_override": [
+        { "asset_group_id": "generation_prompt", "asset_type": "text", "required": true }
+      ]
+    },
+    {
+      "kind": "video_hosted",
+      "asset_source": "seller_pre_rendered_from_brief",
+      "slots_override": [
+        { "asset_group_id": "creative_brief", "asset_type": "brief", "required": true }
+      ]
+    }
+  ]
+}
diff --git a/static/schemas/source/core/creative-asset.json b/static/schemas/source/core/creative-asset.json
index f33adc2d53..f32c890020 100644
--- a/static/schemas/source/core/creative-asset.json
+++ b/static/schemas/source/core/creative-asset.json
@@ -2,12 +2,12 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "/schemas/core/creative-asset.json",
   "title": "Creative Asset",
-  "description": "Creative asset for upload to library - supports static assets, generative formats, and third-party snippets",
+  "description": "Creative asset for upload to library — supports static assets, generative formats, and third-party snippets. Identifies which format this creative conforms to via EITHER a v1 `format_id` (structured `{agent_url, id}`) OR v2 `format_kind` (canonical format name). Mutually exclusive — see the `oneOf` at the schema root.",
   "type": "object",
   "properties": {
     "creative_id": {
       "type": "string",
-      "description": "Unique identifier for the creative",
+      "description": "Unique identifier for the creative. Stable across v1 and v2 paths — a creative registered against v1 `format_id` retains the same `creative_id` when later viewed via v2 flatten.",
       "x-entity": "creative"
     },
     "name": {
@@ -16,14 +16,29 @@
     },
     "format_id": {
       "$ref": "/schemas/core/format-id.json",
-      "description": "Always a structured object {agent_url, id} — never a plain string. Format identifier specifying which format this creative conforms to. Can be: (1) concrete format_id referencing a format with fixed dimensions, (2) template format_id referencing a template format, or (3) parameterized format_id with dimensions/duration parameters for template formats."
+      "description": "v1 path. Always a structured object {agent_url, id} — never a plain string. Format identifier specifying which format this creative conforms to. Can be: (1) concrete format_id referencing a format with fixed dimensions, (2) template format_id referencing a template format, or (3) parameterized format_id with dimensions/duration parameters for template formats. Mutually exclusive with `format_kind`."
+    },
+    "format_kind": {
+      "$ref": "/schemas/core/canonical-format-kind.json",
+      "description": "v2 path. The canonical format name this creative targets (e.g., `image`, `video_hosted`). Mutually exclusive with `format_id`."
+    },
+    "capability_id": {
+      "type": "string",
+      "description": "v2 path, optional. Stable identifier matching one of the seller's product `format_options[i].capability_id` values. REQUIRED only when the target product has multiple `format_options` entries sharing the same `format_kind`."
     },
     "assets": {
       "type": "object",
-      "description": "Assets required by the format, keyed by asset_id. Each asset value carries an `asset_type` discriminator that selects the matching asset schema.",
+      "description": "Assets required by the format, keyed by asset_id. Each slot value is either a single asset object or an array of asset objects (for slots with `min`/`max > 1` like carousel `cards` or responsive_creative `headlines`). Each asset value carries an `asset_type` discriminator that selects the matching asset schema.",
       "patternProperties": {
         "^[a-z0-9_]+$": {
-          "$ref": "/schemas/core/assets/asset-union.json"
+          "oneOf": [
+            { "$ref": "/schemas/core/assets/asset-union.json" },
+            {
+              "type": "array",
+              "items": { "$ref": "/schemas/core/assets/asset-union.json" },
+              "minItems": 1
+            }
+          ]
         }
       },
       "additionalProperties": true
@@ -97,8 +112,21 @@
   "required": [
     "creative_id",
     "name",
-    "format_id",
     "assets"
   ],
+  "oneOf": [
+    {
+      "title": "v1 creative (named-format reference)",
+      "description": "Creative references a named format via the structured `format_id` object. The v1 path; remains supported through 4.x.",
+      "required": ["format_id"],
+      "not": { "required": ["format_kind"] }
+    },
+    {
+      "title": "v2 creative (canonical format kind)",
+      "description": "Creative declares which canonical format it targets via `format_kind` (e.g., `image`). The v2 path introduced by RFC #3305.",
+      "required": ["format_kind"],
+      "not": { "required": ["format_id"] }
+    }
+  ],
   "additionalProperties": true
 }
diff --git a/static/schemas/source/core/creative-manifest.json b/static/schemas/source/core/creative-manifest.json
index 410387e4d7..fc4568e79f 100644
--- a/static/schemas/source/core/creative-manifest.json
+++ b/static/schemas/source/core/creative-manifest.json
@@ -2,23 +2,42 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "/schemas/core/creative-manifest.json",
   "title": "Creative Manifest",
-  "description": "Complete specification of a creative: format_id + assets. Everything the creative needs — images, text, briefs, catalogs — lives in the assets map, declared by the format. Each asset is typed according to its asset_type from the format specification.",
+  "description": "Complete specification of a creative: format identification + assets. A manifest carries EITHER a v1 `format_id` (structured `{agent_url, id}` reference to a named format) OR v2 `format_kind` (the canonical format name the manifest targets, paired with optional `capability_id` for routing when a product's `format_options` contains multiple declarations sharing the same `format_kind`). Mutually exclusive — see the `oneOf` at the schema root. Everything the creative needs — images, text, briefs, catalogs — lives in the assets map, declared by the matching format declaration. Each asset is typed according to its asset_type from the format specification.",
   "type": "object",
   "properties": {
     "format_id": {
       "$ref": "/schemas/core/format-id.json",
-      "description": "Always a structured object {agent_url, id} — never a plain string. Format identifier this manifest is for. Can be a template format (id only) or a deterministic format (id + dimensions/duration). For dimension-specific creatives, include width/height in the format_id to create a unique identifier (e.g., {id: 'display_static', width: 300, height: 250})."
+      "description": "v1 path. Always a structured object {agent_url, id} — never a plain string. Format identifier this manifest is for. Can be a template format (id only) or a deterministic format (id + dimensions/duration). For dimension-specific creatives, include width/height in the format_id to create a unique identifier (e.g., {id: 'display_static', width: 300, height: 250}). Mutually exclusive with `format_kind`."
+    },
+    "format_kind": {
+      "$ref": "/schemas/core/canonical-format-kind.json",
+      "description": "v2 path. The canonical format name this manifest targets (e.g., `image`, `video_hosted`, `audio_daast`, `sponsored_placement`). Selects which canonical the seller validates the manifest's assets against. Mutually exclusive with `format_id`."
+    },
+    "capability_id": {
+      "type": "string",
+      "description": "v2 path, optional. Stable identifier matching one of the seller's product `format_options[i].capability_id` values. REQUIRED when the target product carries multiple `format_options` entries sharing the same `format_kind` (the buyer must disambiguate which option this manifest matches). When the product's `format_options` has a single entry — or multiple entries with distinct `format_kind` values — `capability_id` is OPTIONAL because `format_kind` alone routes the manifest to the right declaration."
     },
     "assets": {
       "type": "object",
-      "description": "Map of asset IDs to actual asset content. Each key MUST match an asset_id from the format's assets array (e.g., 'banner_image', 'clickthrough_url', 'video_file', 'vast_tag'). The asset_id is the technical identifier used to match assets to format requirements.\n\nEach asset value carries an `asset_type` discriminator (image, video, audio, vast, daast, text, markdown, url, html, css, webhook, javascript, brief, catalog) that selects the matching asset schema. Validators with OpenAPI-style discriminator support use `asset_type` to report errors against only the selected branch instead of all branches.",
+      "description": "Map of slot keys to actual asset content. v1 path: each key matches an `asset_id` from the format's `assets` array (e.g., 'banner_image', 'clickthrough_url', 'video_file', 'vast_tag'). v2 path: each key matches an `asset_group_id` from the format's `slots` declaration drawn from the canonical vocabulary registry (e.g., 'images_landscape', 'video', 'landing_page_url', 'vast_tag', 'script', 'creative_brief'). Either path produces the same envelope shape; only the slot-key vocabulary differs.\n\nEach slot value is **either** a single asset object (most slots — image, video, vast_tag, landing_page_url, etc.) **or** an array of asset objects (slots with `min`/`max` counts on the format declaration — `cards` on `image_carousel`, `headlines` / `descriptions` / `images_landscape` on `responsive_creative`, etc.). Single-vs-array shape is governed by the format's `slots[].min` and `slots[].max` parameters: when `max > 1` (or when the slot is conceptually a pool), the value MUST be an array; when the slot is single-valued, the value MUST be a single object. Each asset value (single or array element) carries an `asset_type` discriminator (image, video, audio, vast, daast, text, markdown, url, html, css, webhook, javascript, brief, catalog, zip, card) that selects the matching asset schema. Validators with OpenAPI-style discriminator support use `asset_type` to report errors against only the selected branch instead of all branches.",
       "patternProperties": {
         "^[a-z0-9_]+$": {
-          "$ref": "/schemas/core/assets/asset-union.json"
+          "oneOf": [
+            { "$ref": "/schemas/core/assets/asset-union.json" },
+            {
+              "type": "array",
+              "items": { "$ref": "/schemas/core/assets/asset-union.json" },
+              "minItems": 1
+            }
+          ]
         }
       },
       "additionalProperties": true
     },
+    "brand": {
+      "$ref": "/schemas/core/brand-ref.json",
+      "description": "Brand identity reference (BrandRef — `domain` plus optional `brand_id` for house-of-brands; plus optional inline `brand_kit_override` for per-creative tweaks where brand.json is missing/stale). When present, the seller pulls brand context (logos, colors, voice, taglines) from the brand's brand.json automatically; any `brand_kit_override` fields on the BrandRef take precedence. v2 formats no longer redeclare brand_logo / brand_colors / brand_voice as explicit slots — brand identity is implicit context."
+    },
     "rights": {
       "type": "array",
       "description": "Rights constraints attached to this creative. Each entry represents constraints from a single rights holder. A creative may combine multiple rights constraints (e.g., talent likeness + music license). For v1, rights constraints are informational metadata — the buyer/orchestrator manages creative lifecycle against these terms.",
@@ -43,8 +62,21 @@
     }
   },
   "required": [
-    "format_id",
     "assets"
   ],
+  "oneOf": [
+    {
+      "title": "v1 manifest (named-format reference)",
+      "description": "Manifest references a named format via the structured `format_id` object. The v1 path; remains supported through 4.x.",
+      "required": ["format_id"],
+      "not": { "required": ["format_kind"] }
+    },
+    {
+      "title": "v2 manifest (canonical format kind)",
+      "description": "Manifest declares which canonical format it targets via `format_kind` (e.g., `image`). The v2 path introduced by RFC #3305.",
+      "required": ["format_kind"],
+      "not": { "required": ["format_id"] }
+    }
+  ],
   "additionalProperties": true
 }
diff --git a/static/schemas/source/core/error.json b/static/schemas/source/core/error.json
index 6356123ce3..00b49c88ea 100644
--- a/static/schemas/source/core/error.json
+++ b/static/schemas/source/core/error.json
@@ -88,6 +88,15 @@
       "type": "string",
       "enum": ["transient", "correctable", "terminal"],
       "description": "Agent recovery classification. transient: retry after delay (rate limit, service unavailable, timeout). correctable: fix the request and resend (invalid field, budget too low, creative rejected). terminal: requires human action (account suspended, payment required, account not found)."
+    },
+    "source": {
+      "type": "string",
+      "enum": ["producer", "sdk"],
+      "description": "Who emitted this error entry. `producer` (default when absent): emitted by the response's authoring agent (the seller for `get_products`, the creative agent for `build_creative`, etc.). `sdk`: augmented by a consuming SDK that detected a non-fatal advisory condition on consumption (e.g., `FORMAT_PROJECTION_FAILED` when the buyer SDK couldn't project a v1 format to a canonical, or `FORMAT_DECLARATION_DIVERGENT` when the SDK detected a producer bug on read). SDK-augmented entries SHOULD also set `sdk_id` so downstream consumers can identify which intermediate processor inserted the entry.\n\n**Multi-hop propagation (normative).** AdCP is a federated agent network — responses commonly traverse multiple SDKs (e.g., sales agent → interchange → DSP → buyer). When an SDK augments `errors[]` with a consumption-detected entry, the augmented response carries the entry forward to subsequent hops. Each hop that detects the same condition independently SHOULD deduplicate by `(code, field)` rather than re-emit; the existing entry's `sdk_id` identifies which earlier processor saw it first. Producer entries (those without `source: \"sdk\"`) are authoritative for what the response's authoring agent self-detected; SDK entries are observations made on top.\n\n**Replay/audit safety.** Persisted or replayed responses carry `source` and `sdk_id` so the audit trail can distinguish seller-emitted entries from SDK-augmented ones. Without `source`, a downstream consumer can't tell whether a code came from the seller or an intermediate SDK, which corrupts attribution."
+    },
+    "sdk_id": {
+      "type": "string",
+      "description": "Optional identifier for the SDK that augmented this error entry. Format: `<sdk_package_name>@<version>` (e.g., `@adcontextprotocol/adcp@7.3.0`, `adcontextprotocol-adcp-python@1.2.0`). MUST be set when `source: \"sdk\"`; MUST be absent when `source: \"producer\"` or absent. Lets downstream consumers identify which intermediate processor inserted the entry, useful for debugging cross-SDK divergence (e.g., one SDK detects a projection failure that another SDK's registry version doesn't)."
     }
   },
   "required": [
diff --git a/static/schemas/source/core/format-shape-vocabulary.json b/static/schemas/source/core/format-shape-vocabulary.json
new file mode 100644
index 0000000000..f1a86d7937
--- /dev/null
+++ b/static/schemas/source/core/format-shape-vocabulary.json
@@ -0,0 +1,64 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/format-shape-vocabulary.json",
+  "title": "AdCP Format Shape Vocabulary Registry",
+  "description": "Canonical registry of `format_shape` values used on `ProductFormatDeclaration` when `format_kind: \"custom\"`. Captures recognized creative-structure patterns that are NOT yet first-class canonical formats — composed/coordinated/sponsorship shapes that high-end publishers and broadcast networks sell as headline products. Each registry entry names a global shape; the seller's actual structure lives in `format_schema` (URI+digest reference to the seller-hosted or AAO-mirrored schema) so buyer agents can fetch and validate against a real schema rather than reasoning over an opaque ext blob.\n\n**Two-layer extensibility:**\n- **Canonical** (`format_kind: image`, `video_vast`, etc.): full spec coverage, stable contract.\n- **Custom + format_shape + format_schema** (`format_kind: \"custom\"`): recognized pattern, classified against this vocabulary, but the params/slots structure is supplied by a fetchable schema rather than baked into AdCP.\n\nNon-canonical `format_shape` values remain valid (validators MAY soft-warn) so adopters CAN ship a shape that isn't yet in the registry — adding entries is a vocabulary PR, not a major-version bump. Once a `format_shape` entry sees 2+ adopters with substantively similar `format_schema` content for 90+ days, the working group promotes it to a first-class canonical (creates `/schemas/formats/canonical/<name>.json`, adds the value to `canonical-format-kind.json`, retires the registry entry). See [adcp#3666](https://github.com/adcontextprotocol/adcp/issues/3666) for the promotion queue.\n\n**Promotion migration contract (normative).** Promotion is a wire-shape change for any consumer code branching on `format_kind == \"custom\"` — the same publisher's product now ships under `format_kind: \"<promoted_name>\"`. To avoid silent breakage:\n\n1. **Transition window.** When the working group promotes a `format_shape` to a first-class `format_kind`, sellers MAY ship a product under BOTH shapes during the transition window — two declarations on the same product's `format_options` array, one `format_kind: \"custom\"` + `format_shape: \"<name>\"` and one `format_kind: \"<promoted_name>\"`. Transition window is at minimum 90 days; the promotion PR sets the calendar.\n2. **Consumer-SDK deprecation warning.** SDKs encountering a `format_kind: \"custom\"` declaration whose `format_shape` matches an entry promoted to a first-class canonical SHOULD emit a structured deprecation warning via their lint channel (same pattern as `FORMAT_PROJECTION_FAILED` cross-boundary visibility) carrying `{ format_shape, promoted_to: format_kind, promotion_release, transition_end }`. Adopters branching on `format_kind == \"custom\"` past `transition_end` silently lose that publisher's inventory; the deprecation warning is the early signal.\n3. **`promotion_status` lifecycle.** When promotion is scheduled, the entry's `promotion_status` SHOULD update from `tracking — see adcp#3666` to `promoted to <format_kind> in <version>; transition ends <date>`. SDKs MAY read the registry at codegen / runtime to populate the deprecation warning's `transition_end`.\n4. **Producer-side hygiene.** After the transition window closes, sellers SHOULD drop the legacy `format_kind: \"custom\"` declaration and ship only the first-class canonical. Buyers MAY then assume `format_kind == \"custom\"` + `format_shape: \"<name>\"` is a long-tail / non-promoted shape, not a promoted-canonical-shipped-under-the-old-name.\n\nWithout this contract, every promotion event silently breaks adopter code branching on `format_kind == \"custom\"`. With it, the breakage surfaces as a structured warning during the transition window and adopters can update their branching ahead of the cutover.",
+  "version": "1.0.0",
+  "lastUpdated": "2026-04-30",
+  "vocabulary": {
+    "multi_placement_takeover": {
+      "description": "Coordinated buy targeting several placements at once on a single page or content unit, sold as a unit (homepage skin + banner + preroll + sponsorship lockup, all firing for the same advertiser concurrently). Used by NYTimes, WSJ, Hulu, premium publishers. Multi-canonical composition — the format_schema enumerates each component placement and its own format constraints.",
+      "typical_use": "Premium publisher homepage takeovers, day-part broadcast takeovers, content-section sponsorships",
+      "tracking_model_hint": "Per-component impressions plus a takeover-level engagement metric (time-on-page, scroll depth)",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "roadblock": {
+      "description": "Single advertiser owns all spots in a content unit (every commercial break in a half-hour show, every banner on a section page, every preroll for a content category). Linear-TV-shaped but applies to digital too. Distinct from `multi_placement_takeover` because all spots share the SAME format (ten preroll videos), not different formats coordinated together.",
+      "typical_use": "Linear TV roadblocks, podcast network sponsorships of a content category, all-spots-on-section",
+      "tracking_model_hint": "Per-spot impressions plus exclusivity attestation",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "branded_content": {
+      "description": "Publisher-produced editorial sponsorship (advertorial, sponsored articles, paid features, branded videos). Shape doesn't compose from canonicals — it's its own creative production model where the publisher's editorial team produces the asset from a buyer brief. Distinct from `agent_placement` (AI-surface composition) and `audio_hosted` host-read (shorter-form, scripted-from-buyer).",
+      "typical_use": "NYT T Brand Studio, WSJ Custom Content, Vox Creative",
+      "tracking_model_hint": "Engagement-keyed (time-on-page, scroll depth, video completion) rather than impression-keyed",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "cross_screen_sponsorship": {
+      "description": "Synchronized buys across linear TV / CTV / display / audio. Frequency-capped at the user, not the screen. Concurrent-session-keyed tracking that ties impressions across devices to the same household / individual.",
+      "typical_use": "Live sports sponsorship spanning broadcast + streaming + social, multi-screen reach campaigns",
+      "tracking_model_hint": "Cross-device impression dedup; household-level reach measurement",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "sponsorship_lockup": {
+      "description": "Persistent brand presence over a content window (Hulu's 'commercial-free experience presented by Brand X', podcast network sponsorship lockups, newsletter section sponsorships, Spotify-shaped audio-on-demand sponsorships). Long-duration, low-impression count, premium pricing. Structure: a brand reference + a duration window + (optionally) a small lockup creative (logo, tagline) that persists.",
+      "typical_use": "Premium streaming sponsorships, podcast network presenting sponsorships",
+      "tracking_model_hint": "Window-duration impressions plus a single lockup-creative-view event",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "newsletter_sponsorship": {
+      "description": "Email-embedded creative with newsletter-issue-keyed measurement. Distinct from display because the impression event is open-tracking-pixel-shaped, not page-view-shaped. Distinct from email marketing because the surface is a third-party newsletter (the publisher's), not a brand-owned send.",
+      "typical_use": "Substack newsletter sponsorships, Morning Brew, Axios, The Skimm",
+      "tracking_model_hint": "Open-pixel impressions (proxied via the newsletter's email service); CTR via redirect URLs",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "ar_lens": {
+      "description": "Interactive AR creative (Snap lens, Meta camera filter, TikTok effect). SDK-specific composition model; doesn't fit `html5` because the engagement shape is fundamentally different — face/world tracking, gesture interactions, share-out mechanics, rendered-on-device.",
+      "typical_use": "Snap branded lenses, Meta camera filters, TikTok branded effects",
+      "tracking_model_hint": "Lens-specific events (open, capture, share, time-played) tied to lens_id",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "playable": {
+      "description": "Interactive HTML5 mini-game or experience (Unity playable, IAB MRAID 3.0 playable). Distinct from `html5` banner because engagement is the primary impression event, not view-through.",
+      "typical_use": "Mobile game ads, branded mini-experiences (IKEA Place-shaped AR-lite)",
+      "tracking_model_hint": "Engagement-event-keyed (game start, level complete, completion)",
+      "promotion_status": "tracking — see adcp#3666"
+    },
+    "live_event_sponsorship": {
+      "description": "Sponsorship attached to a specific live broadcast (sports, concert, breaking-news window). Concurrent-impression and stream-state tracking — the impression is bounded by the event's start/end times and may include during-event creative variants.",
+      "typical_use": "Super Bowl pregame sponsorship, live concert streaming sponsorships, breaking-news sponsorship windows",
+      "tracking_model_hint": "Event-window-bounded impressions; stream-state correlation (live vs replay vs ended)",
+      "promotion_status": "tracking — see adcp#3666"
+    }
+  }
+}
diff --git a/static/schemas/source/core/format.json b/static/schemas/source/core/format.json
index b5f43fae7a..6e0fd38d92 100644
--- a/static/schemas/source/core/format.json
+++ b/static/schemas/source/core/format.json
@@ -29,6 +29,10 @@
           "type": "array",
           "description": "Publisher-controlled elements rendered on top of buyer content at this asset's position (e.g., video player controls, publisher logos). Creative agents should avoid placing critical content (CTAs, logos, key copy) within overlay bounds.",
           "items": { "$ref": "/schemas/core/overlay.json" }
+        },
+        "asset_group_id": {
+          "type": "string",
+          "description": "Optional canonical asset_group_id this slot fills, drawn from /schemas/core/asset-group-vocabulary.json. Lets buyers and migration tools resolve v1 author-invented slot names (e.g., `click_url`) to canonical names (e.g., `landing_page_url`). Validators MAY soft-warn when a v1 slot's asset_id is a known alias but no asset_group_id is declared."
         }
       },
       "required": ["item_type", "asset_id", "asset_type", "required"]
@@ -44,6 +48,10 @@
           "type": "string",
           "description": "Descriptive label for this asset's purpose. For documentation and UI display only — manifests key assets by asset_id, not asset_role."
         },
+        "asset_group_id": {
+          "type": "string",
+          "description": "Optional canonical asset_group_id this slot fills, drawn from /schemas/core/asset-group-vocabulary.json. Same semantics as on baseIndividualAsset — lets buyers and migration tools resolve v1 author-invented slot names to canonical names."
+        },
         "required": {
           "type": "boolean",
           "description": "Whether this asset is required within each repetition of the group",
@@ -278,6 +286,15 @@
               "requirements": { "$ref": "/schemas/core/requirements/javascript-asset-requirements.json" }
             }
           },
+          {
+            "title": "IndividualZipAsset",
+            "description": "Zip-bundled asset (HTML5 banner bundles, etc.)",
+            "allOf": [{ "$ref": "#/$defs/baseIndividualAsset" }],
+            "properties": {
+              "item_type": { "const": "individual" },
+              "asset_type": { "const": "zip" }
+            }
+          },
           {
             "title": "IndividualVastAsset",
             "description": "VAST asset",
@@ -462,6 +479,15 @@
                       },
                       "required": ["asset_type"]
                     },
+                    {
+                      "title": "GroupZipAsset",
+                      "description": "Zip-bundled asset in group (HTML5 banner bundles, etc.)",
+                      "allOf": [{ "$ref": "#/$defs/baseGroupAsset" }],
+                      "properties": {
+                        "asset_type": { "const": "zip" }
+                      },
+                      "required": ["asset_type"]
+                    },
                     {
                       "title": "GroupVastAsset",
                       "description": "VAST asset in group",
@@ -645,11 +671,40 @@
         "$ref": "/schemas/core/vendor-pricing-option.json"
       },
       "minItems": 1
+    },
+    "canonical": {
+      "$ref": "/schemas/core/canonical-projection-ref.json",
+      "description": "Optional v2 canonical-projection annotation. Always an object — bare-string shorthand (`canonical: \"image\"`) is not supported; the minimal form is `canonical: { \"kind\": \"image\" }`. Carries `kind` (which canonical the v1 format projects to) plus optional `asset_source` and `slots_override` for cases where the v1 format's shape doesn't follow the canonical's defaults (e.g., generative entries whose input is `generation_prompt: text` instead of `image_main: image`).\n\nWhen set, SDKs use this annotation as the authoritative v1 → v2 mapping for this format, bypassing the [v1 canonical mapping registry](/schemas/registries/v1-canonical-mapping.json) lookup. Combined with the slot-level `asset_group_id` declarations on each `assets[i]` entry, a v1 format declaration with `canonical` set is fully self-describing for v1↔v2 translation.\n\nResolution order for SDK projection from v1 wire shape to v2 (per RFC #3305 amendment #3767):\n1. If this `canonical` field is set, use it (seller-declared, highest priority). Apply `asset_source` and `slots_override` from the projection ref when present; otherwise inherit the canonical's defaults.\n2. Else, look up `format_id` in the canonical mapping registry's `format_id_glob` entries.\n3. Else, attempt structural match against the registry's `structural` entries (asset types, slot shape, vast_versions, etc.).\n4. Else, fail closed: SDK MUST NOT emit `format_options` for products carrying this format. Surface `FORMAT_PROJECTION_FAILED` on the response `errors[]` suggesting the seller add an explicit `canonical` annotation or file a registry entry.\n\nWhen `canonical.kind` is `custom`, the seller MUST also declare `canonical_format_shape` and `canonical_format_schema` (parallel to ProductFormatDeclaration's `format_shape` and `format_schema`) so buyer SDKs can fetch the seller's custom format schema.\n\nSee `canonical-projection-ref.json` for full projection semantics and examples (default-slot case, generative case, brief-driven case)."
+    },
+    "canonical_parameters": {
+      "$ref": "/schemas/core/product-format-declaration.json",
+      "deprecated": true,
+      "description": "**DEPRECATED in 3.1. Removed at 4.0.** Use `v1_format_ref` on the v2 `ProductFormatDeclaration` instead — the seller authors a v2 declaration (in `Product.format_options` or `creative.supported_formats`) and links it back to this v1 format via `v1_format_ref: { agent_url, id }`. The directional link from v2 → v1 is the same fact as `canonical_parameters` without the parallel-shape drift surface (v1 file and `canonical_parameters` were two declarations of the same thing; hand-authored, drifting silently).\n\nMigration: every seller currently authoring `canonical_parameters` SHOULD migrate to authoring a v2 declaration on the corresponding product (or capability) with `v1_format_ref` pointing back at this v1 format. v1 files become pure v1 again — no v2-shape mirroring.\n\n*Legacy behavior, retained for 3.1–3.x backward compatibility:* When `canonical` is set, this field carries the full ProductFormatDeclaration that the SDK projects this v1 format into. The `format_kind` MUST equal the `canonical` field value (validators enforce). When set, this is the authoritative source for SDK v1→v2 projection — the registry's structural-match parameter inference is bypassed. SDKs reading 3.1 catalogs MUST continue to honor `canonical_parameters` when present; 4.0+ SDKs MAY reject the field. New code SHOULD NOT emit this field.\n\n**Drift contract (still normative while supported).** Hand-authored `canonical_parameters` MUST satisfy the *narrows* relation against this v1 format's `requirements` and `assets[*]` shape (see canonical-formats.mdx 'Narrows — formal definition'). SDKs that read this v1 file SHOULD lint-time check the equivalence at build/load and emit `FORMAT_PROJECTION_FAILED` if the two disagree."
     }
   },
   "required": [
     "format_id",
     "name"
   ],
+  "allOf": [
+    {
+      "if": {
+        "required": ["canonical_parameters"]
+      },
+      "then": {
+        "required": ["canonical"],
+        "properties": {
+          "canonical_parameters": {
+            "type": "object",
+            "properties": {
+              "format_kind": {
+                "$comment": "Must agree with the sibling `canonical.kind` field — validators SHOULD assert this constraint at build time. JSON Schema can't directly express cross-field equality without ext keywords."
+              }
+            }
+          }
+        }
+      }
+    }
+  ],
   "additionalProperties": true
 }
diff --git a/static/schemas/source/core/offering-asset-group.json b/static/schemas/source/core/offering-asset-group.json
index b7b50e4620..c3893668e8 100644
--- a/static/schemas/source/core/offering-asset-group.json
+++ b/static/schemas/source/core/offering-asset-group.json
@@ -29,6 +29,7 @@
           { "$ref": "/schemas/core/assets/daast-asset.json" },
           { "$ref": "/schemas/core/assets/css-asset.json" },
           { "$ref": "/schemas/core/assets/javascript-asset.json" },
+          { "$ref": "/schemas/core/assets/zip-asset.json" },
           { "$ref": "/schemas/core/assets/webhook-asset.json" }
         ],
         "discriminator": {
diff --git a/static/schemas/source/core/placement-definition.json b/static/schemas/source/core/placement-definition.json
index 7dc30177cd..b88c2411b8 100644
--- a/static/schemas/source/core/placement-definition.json
+++ b/static/schemas/source/core/placement-definition.json
@@ -51,12 +51,39 @@
     },
     "format_ids": {
       "type": "array",
-      "description": "Optional format IDs supported by this placement across the scoped properties and collections. Lets buyers answer which formats are available on which placements without relying on product-local definitions alone.",
+      "description": "Optional v1 format IDs supported by this placement across the scoped properties and collections. Lets buyers answer which formats are available on which placements without relying on product-local definitions alone. Parallel to `format_options[]` (canonical-formats v2 shape) — placements MAY carry either or both during the v1↔v2 migration window. When both are present, `format_options[]` is authoritative for buyers reading canonical-formats; `format_ids[]` is the v1 wire fallback.",
       "items": {
         "$ref": "/schemas/core/format-id.json"
       },
       "minItems": 1
     },
+    "format_options": {
+      "type": "array",
+      "description": "Optional canonical-formats v2 declarations supported by this placement. Two ways to populate an entry: (1) reference an entry in the file's top-level `formats[]` by `capability_id` only — buyers resolve the full declaration from `formats[]` by matching `capability_id` (recommended; avoids duplication). (2) carry an inline `ProductFormatDeclaration` directly — for placement-specific narrowing that doesn't fit a reusable catalog entry. Same anyOf pattern as Product.\n\n**Capability-reference shape.** A capability-reference entry SHOULD carry ONLY `capability_id` — extra fields are allowed (`additionalProperties: true`) so adopters who want to attach a placement-local override like `display_name` don't get rejected by the branch boundary, but buyer SDKs MUST resolve the format from the top-level `formats[]` by `capability_id` and apply additional fields on the entry as placement-level overrides (NOT as a partial inline declaration). If a publisher needs to materially narrow the format at the placement, use the inline-declaration form instead.\n\n**Resolution scope is same-file only.** `capability_id` resolves only within this file's top-level `formats[]`; cross-file references are not supported by design. When `format_options[]` references a `capability_id` not declared in the file's top-level `formats[]`, validators MUST surface this as `FORMAT_CAPABILITY_UNRESOLVED` on the response `errors[]`. Buyers MUST fail closed for that placement (drop the format from the placement's accepted set) rather than silently dropping the placement or guessing intent.",
+      "items": {
+        "anyOf": [
+          {
+            "type": "object",
+            "title": "Capability reference",
+            "description": "Reference an entry in the file's top-level `formats[]` by `capability_id`. Resolved at validation time. additionalProperties: true so placement-local fields (display_name, etc.) carry through without forcing a full inline declaration.",
+            "required": ["capability_id"],
+            "properties": {
+              "capability_id": {
+                "type": "string",
+                "description": "Matches a `capability_id` in the file's top-level `formats[]`."
+              }
+            },
+            "additionalProperties": true
+          },
+          {
+            "$ref": "/schemas/core/product-format-declaration.json",
+            "title": "Inline declaration",
+            "description": "Inline canonical-formats v2 declaration. Use when the placement narrows a format in a way that's not worth a top-level catalog entry."
+          }
+        ]
+      },
+      "minItems": 1
+    },
     "ext": {
       "$ref": "/schemas/core/ext.json"
     }
diff --git a/static/schemas/source/core/platform-extension-ref.json b/static/schemas/source/core/platform-extension-ref.json
new file mode 100644
index 0000000000..1c96326d06
--- /dev/null
+++ b/static/schemas/source/core/platform-extension-ref.json
@@ -0,0 +1,28 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/platform-extension-ref.json",
+  "title": "Platform Extension Reference",
+  "description": "Reference to a platform extension definition. The agent that owns the URI is authoritative for the extension's schema. Buyers fetch the definition once per content digest and cache it. Platform extensions are typically bundled in `get_products` responses under an `extensions` map keyed by `uri@digest`, eliminating the need for a separate fetch.\n\n**Within a single response**, multiple references to the same `uri` MUST carry the same `digest` — divergent digests in one response indicate producer-side error (e.g., concurrent extension revision mid-render). Buyers encountering divergent digests for the same URI MUST fail closed: treat all references to that URI as unresolved and surface a validation error rather than picking one branch silently. **Across responses**, digest divergence is normal — extension authors revise their schemas, the new digest differs, the cache key changes, and the buyer refetches. Cache by `uri@digest`, not by `uri` alone.",
+  "type": "object",
+  "required": ["uri", "digest"],
+  "properties": {
+    "uri": {
+      "type": "string",
+      "format": "uri",
+      "pattern": "^https://",
+      "description": "HTTPS URL identifying the extension. `https://` is mandatory — `http://`, `file://`, `data:`, and other schemes are rejected at the schema layer (defense-in-depth on top of the fetch-contract normative rules). The URI base is the owning agent's URL; the path identifies the extension within that agent. Example: 'https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel'. The full fetch contract — SSRF allowlist, response-size cap, $ref sandbox, schema-compile bounds — is documented on `product-format-declaration.json#format_schema` and applies to ALL fetches of this reference shape regardless of whether the field is named `format_schema` (load-bearing for validation) or `platform_extensions` (informational); the *transport* rules are identical, only the *consumption* semantics differ."
+    },
+    "digest": {
+      "type": "string",
+      "pattern": "^sha256:[a-f0-9]{64}$",
+      "description": "SHA-256 content digest of the extension definition (sha256:<hex>). Used to detect drift — if the agent revises the extension, the digest changes and cached definitions become invalid."
+    }
+  },
+  "additionalProperties": true,
+  "examples": [
+    {
+      "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel",
+      "digest": "sha256:a3f5b7c9d8e2f1a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2"
+    }
+  ]
+}
diff --git a/static/schemas/source/core/product-format-declaration.json b/static/schemas/source/core/product-format-declaration.json
new file mode 100644
index 0000000000..48245b03b0
--- /dev/null
+++ b/static/schemas/source/core/product-format-declaration.json
@@ -0,0 +1,287 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/core/product-format-declaration.json",
+  "title": "Product Format Declaration",
+  "description": "Inline format declaration on a product. The `format_kind` discriminator names which canonical format the product narrows; `params` carries the canonical's parameter schema (slots, dimensions, durations, codecs, character limits, platform_extensions, etc.). Optional `capability_id` (stable identifier for routing when a product's `format_options` contains multiple declarations sharing the same `format_kind`), `display_name` (seller-controlled human-readable label for dashboard and catalog UIs), and `applies_to_channels` (subset of the product's declared channels this declaration applies to — lets a multi-channel product carry distinct format_options per channel). Discriminated-union shape generates clean tagged unions in TypeScript and Pydantic codegen. Replaces v1's named-format pattern (where products referenced a separately-defined format file via compound `format_id`). v1 named formats remain supported through the deprecation cycle; v2 product-bound declarations are opt-in.\n\n**Closed-set semantics (normative).** `format_options[]` is the closed set of accepted formats for this product. Sellers MUST reject `create_media_buy` requests targeting any `format_kind` (or `capability_id`) not present in this list — typically with `UNSUPPORTED_FEATURE` or a seller-specific code; the rejection is structural, not negotiable. `seller_preference` modulates *within* the accepted set (a soft ranking hint between equally-acceptable options), it is NOT an enforcement axis. A product wanting to say 'this format is the only one that works' lists exactly that one entry in `format_options[]`; everything else falls outside the set and is rejected by the closed-set rule.\n\n**Custom format_kind** (`format_kind: \"custom\"`): for adopter-defined shapes that don't fit the 12 canonicals (multi-placement takeover, roadblock, branded content, cross-screen sponsorship, sponsorship lockup, newsletter sponsorship, AR lens, playable, live event sponsorship). When `format_kind` is `custom`, the declaration MUST carry `format_shape` (recognized global pattern from the [format-shape vocabulary registry](/schemas/core/format-shape-vocabulary.json)) AND `format_schema` (URI+digest reference to a fetchable schema describing the actual `params` and `slots`). Buyer agents fetch the schema, validate manifests structurally, and reason about manifests without per-seller integration code. See [adcp#3666](https://github.com/adcontextprotocol/adcp/issues/3666) for the canonical promotion queue.",
+  "type": "object",
+  "required": ["format_kind", "params"],
+  "discriminator": { "propertyName": "format_kind" },
+  "properties": {
+    "capability_id": {
+      "type": "string",
+      "description": "Optional stable identifier for this format declaration. REQUIRED when the parent product's `format_options` contains multiple declarations sharing the same `format_kind` (so buyers can disambiguate which option a manifest targets via `manifest.capability_id`). Recommended for any declaration that may be referenced by capability_id over time. Format-internal (not a URI). Examples: 'flashtalking_image_300x250', 'pmax_responsive_search'."
+    },
+    "display_name": {
+      "type": "string",
+      "description": "Optional seller-controlled human-readable label for this format declaration. Used by buyer dashboards, catalog UIs, and reporting surfaces to show a seller's own naming ('Homepage Takeover', 'Branded Canvas', 'Reels Premium Video') rather than the raw `format_kind` or `capability_id`. Has no machine semantics — buyer agents route on `format_kind` and `capability_id`; `display_name` is purely for human presentation. Freeform; no enumeration. Sellers SHOULD keep it stable once published to avoid dashboard churn."
+    },
+    "applies_to_channels": {
+      "type": "array",
+      "items": { "$ref": "/schemas/enums/channels.json" },
+      "uniqueItems": true,
+      "description": "Optional subset of the parent product's `channels` to which this declaration applies. When omitted, the declaration applies to ALL channels declared on the product. Lets a multi-channel product (e.g., `channels: ['display', 'video']`) carry distinct format_options per channel — `format_options: [{format_kind: 'image', applies_to_channels: ['display']}, {format_kind: 'video_hosted', applies_to_channels: ['video']}]`. Buyers ship channel-appropriate manifests per `applies_to_channels`."
+    },
+    "seller_preference": {
+      "type": "string",
+      "enum": ["preferred", "accepted", "discouraged"],
+      "description": "Optional soft routing hint *within* a product's accepted set of formats — NOT an enforcement axis. `preferred` — seller actively recommends this format (often because of measurement, viewability, or render-quality differences); `accepted` — supported on equal footing with other format_options (default when omitted); `discouraged` — supported but suboptimal (e.g., legacy 3p-tag where the seller would prefer html5 for OM-SDK coverage). Buyer agents picking between format_options SHOULD respect seller preferences when their own constraints don't override.\n\n**Not an enforcement axis (normative).** `seller_preference` does NOT carry the meaning of 'this format won't work / required-only'. That case is structural: `format_options[]` IS the closed set of accepted formats; anything outside the list is rejected at `create_media_buy` regardless of preference. A seller that accepts only one format lists exactly that one entry — the structural fact does the enforcement work, no enum value needed. There is intentionally no `required` value; preference is bounded to *ranking within the already-accepted set*, not gating into it."
+    },
+    "canonical_formats_only": {
+      "type": "boolean",
+      "default": false,
+      "description": "When true, this format declaration has no clean v1 projection and SDKs MUST NOT synthesize a v1 `format_id` for it. Buyers reading the product on the v1 wire path see this declaration absent from `format_ids`; only v2-aware buyers (reading `format_options`) discover it. Set explicitly for `format_kind: \"custom\"` declarations (no canonical exists in v1 to project onto) and for declarations whose canonical/parameter shape cannot round-trip through a v1 named format without semantic loss. The protocol does NOT mint synthetic v1 format_ids for unmappable declarations — the alternative (an `aao-synth/*` namespace populated automatically) was considered and rejected because adopters would index on synthetic IDs that have no stable identity. Producers SHOULD set `canonical_formats_only: true` rather than omit the declaration from `format_options` — explicit v2-only is more useful than silent absence."
+    },
+    "experimental": {
+      "type": "boolean",
+      "default": false,
+      "description": "When true, THIS seller's specific product declaration may not work as declared — even if the underlying canonical is stable. Use for beta runtime paths, forward-looking catalog entries the runtime doesn't yet honor, or experimental products where the seller wants buyer-side caution. Buyers reading `experimental: true` on a product declaration SHOULD prefer the v1 path when a v1 fallback exists for the same product (via `format_ids` on the parent product or via this declaration's `v1_format_ref`) and SHOULD validate via `validate_input` or a sandbox before routing production budget.\n\nIndependent of the canonical's own `experimental` flag — a stable canonical (e.g., `image`, `video_hosted`) can carry an experimental product declaration when the seller is shipping a new runtime path that isn't fully wired yet. Conversely, an experimental canonical (`sponsored_placement`, `responsive_creative`, `agent_placement`) MAY carry non-experimental product declarations where the seller's adopter contract is well-tested. Buyer SDKs SHOULD filter products with `experimental: true` from default views and offer an opt-in flag to surface them.\n\nReplaces the earlier `runtime_status` enum (`stable | preview | declared_only`) — same semantic ('use with caution') without the cognitive overhead of two stability axes."
+    },
+    "format_shape": {
+      "type": "string",
+      "description": "REQUIRED when `format_kind: \"custom\"`; otherwise MUST be absent. Recognized global pattern this custom shape is an instance of, drawn from the [format-shape vocabulary registry](/schemas/core/format-shape-vocabulary.json) (`multi_placement_takeover`, `roadblock`, `branded_content`, `cross_screen_sponsorship`, `sponsorship_lockup`, `newsletter_sponsorship`, `ar_lens`, `playable`, `live_event_sponsorship`, …). Non-canonical values valid (validators MAY soft-warn) — adopters CAN ship a shape that isn't yet in the registry. Adding entries is a vocabulary PR. Once a `format_shape` entry sees 2+ adopters with substantively similar `format_schema` content for 90+ days, the working group promotes it to a first-class canonical."
+    },
+    "v1_format_ref": {
+      "type": "array",
+      "minItems": 1,
+      "items": { "$ref": "/schemas/core/format-id.json" },
+      "description": "Authoritative v2 → v1 link, expressed as an array of one or more v1 `format_id` ({agent_url, id}) values. Each entry asserts that this canonical-formats declaration IS the same underlying format as the referenced v1 named format. Always an array (single-ref is `[{...}]`) so the multi-size case below has a clean wire shape — adopters surveyed in the SDK implementor review pushed for this over the lossy single-ref form.\n\nThe v2 declaration's `params` MUST narrow (be compatible with) each referenced v1 format's `requirements` — see the 'Narrows — formal definition' section in canonical-formats.mdx. SDKs comparing dual-emitted shapes (`Product.format_ids[]` ⊇ entries from `v1_format_ref` AND `Product.format_options[]` carrying this declaration) treat the link as the authoritative pairing and run the narrowing check between this declaration and EACH referenced v1 format file's `requirements`.\n\n**Multi-size fan-out (normative).** When the declaration carries `params.sizes: [{w,h}, ...]` (multi-size flexible slot), sellers SHOULD carry one `v1_format_ref[]` entry per size, each pointing at the per-size v1 named format in the AAO catalog. Example: a multi-size image declaration with `sizes: [300x250, 728x90, 970x250]` SHOULD carry `v1_format_ref: [{aao, display_300x250_image}, {aao, display_728x90_image}, {aao, display_970x250_image}]`. v1-only buyers then see the product on all three sizes via the `format_ids[]` dual-emission. When `v1_format_ref[]` count < `sizes[]` count, SDKs MUST emit `FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE` on the response `errors[]` (advisory, alongside the partial-coverage v1 emit — NOT in place of it). SDKs MAY (non-normative) fan out automatically by catalog lookup when `v1_format_ref[]` has length 1 and `sizes[]` has length N — opt-in, requires catalog access; sellers asserting refs is the source of truth.\n\nMutually exclusive with `canonical_formats_only: true` — a declaration can EITHER assert no v1 projection (`canonical_formats_only: true`) OR link to v1 named formats (`v1_format_ref[]`), never both. When neither is present, SDKs fall back to the resolution order in `v1-canonical-mapping.json` (seller's explicit `canonical` field on the v1 file → registry glob → structural match → fail-closed).\n\nThis is the v2-side authoritative replacement for the v1-side `canonical_parameters` field on `format.json` (which is deprecated for 3.1, removed at 4.0). Sellers SHOULD prefer authoring v2 declarations with `v1_format_ref[]` over mirroring the v2 shape onto v1 files via `canonical_parameters`; the directional link (v2 declaration → v1 identifiers) is the same fact without the parallel-shape drift surface.\n\n**AAO-hosted convention (normative).** For IAB-standard formats (image dimensions, VAST/DAAST tags, standard third-party tags, HTML5 banner bundles), sellers SHOULD point each `v1_format_ref[].agent_url` at the AAO-hosted canonical agent URL `https://creative.adcontextprotocol.org` and use the registry-published id (e.g., `display_300x250_image`, `video_vast_30s`, `audio_standard_30s`, `display_300x250_html`, `display_js`). This converges the v1-wire namespace: every seller's IAB MREC points at the same `{agent_url, id}` pair, so v1-only buyers' allowlists work uniformly. Without this convention, every publisher's 300x250 ships with a different `v1_format_ref` (theirs vs nytimes.example vs cnn.example vs …) and the v1 wire fragments into per-publisher namespaces — exactly what canonical-formats was designed to eliminate.\n\nFor platform-specific formats (Meta Reels, TikTok Spark, Snap Spotlight, etc.), each `v1_format_ref[].agent_url` SHOULD point at the platform's own agent_url when the platform has adopted AdCP and publishes its own `adagents.json` with `formats[]`. When the platform has NOT adopted AdCP, sellers SHOULD point at the AAO community-registry mirror — `https://creative.adcontextprotocol.org/translated/<platform>` + `id: <platform-format-name>` (e.g., `https://creative.adcontextprotocol.org/translated/meta` + `id: meta_reels`). This keeps the v1 namespace converged across all sellers selling that platform's inventory until the platform owns its own adagents.json.\n\n**Platform-adoption cutover (normative).** When a platform adopts AdCP and publishes its own adagents.json, sellers MUST update `v1_format_ref[].agent_url` to the platform's adopted agent_url in the same minor release as the AAO mirror entry's `superseded_by` field goes live (see `static/schemas/source/adagents.json#superseded_by`). The AAO mirror entry SHOULD continue serving for ≥1 minor release after `superseded_by` is set, returning an advisory 'superseded' marker so v1 buyer allowlists keyed on the mirror URL get an explicit signal rather than a silent break. **Identity-confusion note**: the mirror URL is *format-shape namespace*, NOT seller identity. Inventory authorization always flows from `authorized_agents[]` + publisher signing keys; a buyer matching `v1_format_ref[].agent_url` against an allowlist is matching format-shape provenance, not seller identity.\n\n**Mirror domain migration (3.1).** Earlier drafts used `https://mirror.adcontextprotocol.org/translated/<platform>`. As of this release, the convention is `https://creative.adcontextprotocol.org/translated/<platform>` — sibling content under the AAO catalog domain we already host. Adopters who hardcoded the earlier mirror URL MUST migrate to the new path; the canonical-formats.mdx migration section documents the move. No transitional redirect is currently published (the earlier subdomain was never provisioned).\n\nFor seller-bespoke formats (a publisher's `acme_homepage_takeover` that doesn't fit IAB conventions), each `v1_format_ref[].agent_url` is the seller's own agent_url and the id is seller-namespaced. These won't appear in `v1-canonical-mapping.json`'s registry; they're seller-asserted only."
+    },
+    "format_schema": {
+      "$ref": "/schemas/core/platform-extension-ref.json",
+      "description": "REQUIRED when `format_kind: \"custom\"`; otherwise MUST be absent. URI+digest reference to a fetchable schema describing this custom shape's actual `params` and `slots`. Same hosting model as `platform_extensions`: open-ecosystem publishers host the artifact at the canonical URI on their subdomain; closed-platform / walled-garden shapes resolve through the AAO mirror at `https://creative.adcontextprotocol.org/translated/...`. Buyer agents fetch by `uri@digest` (immutable per digest, aggressive caching, `Cache-Control: public, max-age=31536000, immutable`), validate `params` and `slots` against the fetched schema, and reason about manifests structurally — same mechanic as platform_extensions but at the format-structure level. Without `format_schema`, custom shapes would be opaque to buyer agents and the protocol would regress to per-seller integration code; that's why the schema is required, not optional.\n\n**Fetch contract (normative)** — `format_schema` is load-bearing for validation (unlike `platform_extensions`, which is informational on the *consumption* side). The *transport* rules below apply identically to BOTH fields — any SDK fetching a `platform-extension-ref.json` URI MUST apply this contract regardless of whether the field name is `format_schema` or `platform_extensions`. A shared SDK fetch path that drops to the weakest bar undermines `format_schema`'s hardening. The consumption distinction (load-bearing vs informational) is about *what the body means*; the transport distinction is `https`-and-allowlisted regardless.\n\n- **Transport**: `https` only. Buyers MUST reject `http://`, `file://`, `data:`, and any non-`https` scheme. The URI MUST resolve to a JSON document that is itself a valid JSON Schema (Draft 07 or 2020-12; producers MUST declare `$schema`).\n- **SSRF protection**: buyers MUST resolve the URI hostname and reject if any resolved address is in RFC 1918 private space (`10.0.0.0/8`, `172.16.0.0/12`, `192.168.0.0/16`), loopback (`127.0.0.0/8`, `::1`), link-local (`169.254.0.0/16`, `fe80::/10`), CGNAT (`100.64.0.0/10`), or any RFC 6761 special-use name (`.local`, `.localhost`, `.internal`, `.test`, `.example`, `.invalid`). Cloud metadata endpoints (`169.254.169.254`, `metadata.google.internal`, `kubernetes.default.svc`) are explicitly forbidden — these are credential-leak primitives. Buyers MUST pin the connection to the resolved IP (or re-resolve and re-validate the allowlist per request) to defeat DNS rebinding.\n- **HTTP redirects**: MUST be disabled. If a follow is implemented at all, the redirect target MUST pass the same scheme + SSRF + allowlist checks; otherwise the fetch hard-fails. Open redirects on same-origin paths are otherwise a free SSRF primitive.\n- **Response size cap**: response body MUST be capped at 1 MiB. Enforce during streaming, not after full buffering. Over-cap hard-fails identically to digest mismatch.\n- **Timeout**: SDKs SHOULD apply a fetch timeout ≤5 seconds. Timeout SHOULD be treated identically to an HTTP 5xx response (transient — retry policy at the SDK's discretion; on persistent failure surface as unresolved and skip the declaration for this session).\n- **Digest verification**: SHA-256 of the response body MUST equal `digest`. **Digest mismatch is a hard fail** — the buyer MUST treat the format declaration as unresolvable and MUST NOT validate manifests against the mismatched body. A divergent digest is either a malicious substitution or producer error; either way, falling back to the un-verified body breaks the trust model. Digest format: `sha256:` prefix + 64 lowercase hex characters. Cache key is `uri@digest`; digest mismatch MUST NOT be cached as a negative result keyed on `uri` alone (defeats CDN-flap recovery), and MUST be distinguishable in telemetry from network 5xx / 404 (sustained mismatch is a substitution-attack signal, not a flap).\n- **Sandboxing of `$ref`**: fetched schemas MAY use `$ref`. Buyers MUST resolve `$ref` only to URIs that are (a) same-origin as the parent `format_schema.uri` after RFC 3986 §6 normalization (lowercase scheme + host, strip default port, normalize path dot-segments, no userinfo component), OR (b) hosted under the AAO mirror namespace (`https://mirror.adcontextprotocol.org/...`), OR (c) intra-document JSON Pointer refs (`#/...`) bounded to the parent document's parsed tree. Cross-origin `$ref` to arbitrary URIs MUST be rejected. `$ref: file://...` MUST be rejected unconditionally. Transitive `$ref` chains MUST be bounded at depth ≤8 AND `$ref` count ≤256 across the resolved tree (depth 8 with breadth 100 per level is 10^16 nodes — depth alone is not enough). Publishers SHOULD inline rather than $ref where possible.\n- **Schema-compile bounds (DoS protection)**: validators MUST bound CPU/memory on fetched schemas. Recommended: compiled-schema keyword count ≤10 000, `pattern` regexes evaluated with a non-backtracking engine (re2) OR under a per-pattern timeout, per-manifest validation budget ≤250 ms (exceeded budget → treat manifest as invalid, surface telemetry signal). Without these, a 'valid' schema with catastrophic regex backtracking or exponential `allOf`/`anyOf` expansion pins a CPU forever.\n- **Cache**: buyers cache fetched schemas by `uri@digest` and treat them as immutable (the same hosting contract as `platform_extensions`). On `404`, network partition, or persistent fetch failure, buyers SHOULD degrade gracefully (treat the declaration as unresolved, skip it for the current `get_products` response, surface via `errors[]` with the relevant code) rather than failing the entire session.\n- **Schema-not-valid handling**: if the fetched body parses as JSON but is not a valid JSON Schema, the buyer MUST treat the declaration as unresolvable (same as digest mismatch) and surface via `errors[]`. Validators MUST NOT attempt partial validation against an invalid schema.\n- **AAO mirror trust**: `https://mirror.adcontextprotocol.org/*` is a single trust anchor in the same-origin allowlist; compromise of the mirror or its CA compromises every buyer agent. Mirror-served bodies MUST be digest-pinned identically to origin fetches (the digest is on the *parent* `format_schema.uri@digest`, not on the mirror response). Future hardening (signed bodies, transparency log) is tracked separately."
+    }
+  },
+  "allOf": [
+    {
+      "if": {
+        "properties": { "format_kind": { "const": "custom" } },
+        "required": ["format_kind"]
+      },
+      "then": {
+        "required": ["format_shape", "format_schema"],
+        "anyOf": [
+          {
+            "properties": { "canonical_formats_only": { "const": true } },
+            "required": ["canonical_formats_only"]
+          },
+          { "required": ["v1_format_ref"] }
+        ]
+      },
+      "else": {
+        "not": { "anyOf": [
+          { "required": ["format_shape"] },
+          { "required": ["format_schema"] }
+        ] }
+      }
+    },
+    {
+      "$comment": "canonical_formats_only:true and v1_format_ref are mutually exclusive — a declaration EITHER asserts no v1 projection OR links to a v1 named format, never both.",
+      "not": {
+        "allOf": [
+          {
+            "properties": { "canonical_formats_only": { "const": true } },
+            "required": ["canonical_formats_only"]
+          },
+          { "required": ["v1_format_ref"] }
+        ]
+      }
+    }
+  ],
+  "oneOf": [
+    {
+      "title": "Image Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "image" },
+        "params": { "$ref": "/schemas/formats/canonical/image.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "HTML5 Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "html5" },
+        "params": { "$ref": "/schemas/formats/canonical/html5.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Display Tag Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "display_tag" },
+        "params": { "$ref": "/schemas/formats/canonical/display_tag.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Image Carousel Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "image_carousel" },
+        "params": { "$ref": "/schemas/formats/canonical/image_carousel.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Hosted Video Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "video_hosted" },
+        "params": { "$ref": "/schemas/formats/canonical/video_hosted.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "VAST Video Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "video_vast" },
+        "params": { "$ref": "/schemas/formats/canonical/video_vast.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Hosted Audio Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "audio_hosted" },
+        "params": { "$ref": "/schemas/formats/canonical/audio_hosted.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "DAAST Audio Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "audio_daast" },
+        "params": { "$ref": "/schemas/formats/canonical/audio_daast.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Sponsored Placement Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "sponsored_placement" },
+        "params": { "$ref": "/schemas/formats/canonical/sponsored_placement.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Native In-Feed Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "native_in_feed" },
+        "params": { "$ref": "/schemas/formats/canonical/native_in_feed.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Responsive Creative Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "responsive_creative" },
+        "params": { "$ref": "/schemas/formats/canonical/responsive_creative.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Agent Placement Format Declaration",
+      "properties": {
+        "format_kind": { "type": "string", "const": "agent_placement" },
+        "params": { "$ref": "/schemas/formats/canonical/agent_placement.json" }
+      },
+      "required": ["format_kind", "params"]
+    },
+    {
+      "title": "Custom Format Declaration",
+      "description": "Adopter-defined shape that doesn't fit the 12 canonicals. Requires `format_shape` (vocabulary-registered global pattern) and `format_schema` (URI+digest reference to a fetchable schema describing the actual params/slots). `params` shape is governed by the fetched schema rather than baked into AdCP — kept as `type: object` here with `additionalProperties: true` because the canonical schema validates dynamically post-fetch.",
+      "properties": {
+        "format_kind": { "type": "string", "const": "custom" },
+        "params": {
+          "type": "object",
+          "additionalProperties": true,
+          "description": "Custom shape's params. Validated against the schema fetched from `format_schema.uri` at the cached `format_schema.digest`."
+        }
+      },
+      "required": ["format_kind", "params"]
+    }
+  ],
+  "examples": [
+    {
+      "description": "Meta Reels — narrows video_hosted (vertical orientation)",
+      "data": {
+        "format_kind": "video_hosted",
+        "params": {
+          "orientation": "vertical",
+          "aspect_ratio": "9:16",
+          "duration_ms_range": [3000, 90000],
+          "min_width": 1080,
+          "min_height": 1920,
+          "max_file_size_mb": 200,
+          "video_codecs": ["h264"],
+          "audio_codecs": ["aac"],
+          "headline_max_chars": 25,
+          "primary_text_max_chars": 72,
+          "captions": "recommended",
+          "cta_values": ["LEARN_MORE", "SHOP_NOW", "DOWNLOAD", "SIGN_UP"],
+          "composition_model": "deterministic",
+          "platform_extensions": [
+            { "uri": "https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel", "digest": "sha256:a3f5b7c9d8e2f1a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2" }
+          ]
+        }
+      }
+    },
+    {
+      "description": "IAB Medium Rectangle (300x250) — narrows image",
+      "data": {
+        "format_kind": "image",
+        "params": {
+          "width": 300,
+          "height": 250,
+          "max_file_size_kb": 200,
+          "image_formats": ["jpg", "png", "gif"],
+          "ssl_required": true,
+          "composition_model": "deterministic",
+          "cta_values": ["LEARN_MORE", "SHOP_NOW", "GET_OFFER"]
+        }
+      }
+    },
+    {
+      "description": "Podcast 30s host-read — narrows audio_hosted with a `script` slot the seller's host reads verbatim. No separate `inputs` map; the script lives in the manifest's `assets` like any other text asset.",
+      "data": {
+        "format_kind": "audio_hosted",
+        "params": {
+          "duration_ms_exact": 30000,
+          "audio_codecs": ["mp3", "aac"],
+          "audio_sample_rates": [44100, 48000],
+          "audio_channels": ["stereo"],
+          "loudness_lufs": -16,
+          "asset_source": "publisher_host_recorded",
+          "buyer_asset_acceptance": "rejected",
+          "composition_model": "deterministic",
+          "slots": [
+            { "asset_group_id": "script", "required": true, "asset_type": "text", "max_chars": 800 },
+            { "asset_group_id": "offering_ref", "required": false, "asset_type": "text" }
+          ],
+          "production_window_business_days": 7
+        }
+      }
+    },
+    {
+      "description": "NYTimes Homepage Takeover — custom format_kind, classified against the multi_placement_takeover format_shape, with format_schema pointing at NYTimes's hosted schema. Buyer agents fetch the schema by uri@digest (cached, immutable) and validate the manifest structurally. `canonical_formats_only: true` is required for custom declarations — no v1 named format can express the multi-placement shape.",
+      "data": {
+        "format_kind": "custom",
+        "canonical_formats_only": true,
+        "format_shape": "multi_placement_takeover",
+        "format_schema": {
+          "uri": "https://nytimes.example/schemas/formats/homepage_takeover_v3",
+          "digest": "sha256:e1d4f6a9c2b5e8d1f4a7c0b3e6d9f2a5c8b1e4d7f0a3c6b9e2d5f8a1c4b7e0a3"
+        },
+        "capability_id": "nytimes_homepage_takeover_premium",
+        "display_name": "Homepage Takeover — Premium Sponsorship",
+        "applies_to_channels": ["display", "olv"],
+        "params": {
+          "components": [
+            { "placement_type": "homepage_skin", "required": true },
+            { "placement_type": "preroll_video", "required": true },
+            { "placement_type": "sponsorship_lockup", "required": true }
+          ],
+          "exclusivity_window_hours": 24,
+          "ssl_required": true
+        }
+      }
+    }
+  ]
+}
diff --git a/static/schemas/source/core/product.json b/static/schemas/source/core/product.json
index 2cda078d76..f9dca3f53d 100644
--- a/static/schemas/source/core/product.json
+++ b/static/schemas/source/core/product.json
@@ -39,11 +39,19 @@
     },
     "format_ids": {
       "type": "array",
-      "description": "Array of supported creative format IDs - structured format_id objects with agent_url and id",
+      "description": "v1 path: array of supported creative format IDs (structured format_id objects with agent_url and id). Products MUST carry `format_ids`, `format_options`, or BOTH; at least one is required. v1 named formats remain supported through the v1-deprecation calendar (2027-Q4 floor / 2029-Q1 ceiling).\n\n**Dual emission**: A product MAY carry both `format_ids` and `format_options` simultaneously during the migration window. This is the recommended seller pattern — author once, SDK projects to both wire shapes via the [v1↔v2 canonical mapping registry](/schemas/registries/v1-canonical-mapping.json), every buyer reads what it knows. When both are present, the two MUST refer to the SAME underlying format declaration (the `format_options[i]` narrows the canonical that the named format in `format_ids[i]` resolves to via the registry / explicit `canonical` field). SDKs that derive both shapes from one source guarantee this invariant; SDKs that don't MUST treat divergence as a build error and refuse to emit. **Buyer rule**: when both are present, prefer `format_options`; treat `format_ids` as fallback for v1-only buyers. **Non-projectable formats**: when a v1 named format has no clean v2 projection (no registry entry, no explicit `canonical` declaration on the v1 format, no structural match), SDKs MUST NOT emit `format_options` for that product — only `format_ids` ships, and the product remains v1-only until the seller adds an explicit `canonical` field or files a registry entry.",
       "items": {
         "$ref": "/schemas/core/format-id.json"
       }
     },
+    "format_options": {
+      "type": "array",
+      "minItems": 1,
+      "description": "v2 path: one or more inline format declarations the product accepts. Each element narrows a canonical format with parameters, slots, and platform_extensions. The 90% case is a single-element array (one canonical narrowed for the product). Multi-element use cases: a product that accepts EITHER a third-party-hosted creative (e.g., Flashtalking-served `html5`) OR an internal `display_tag`; a video product that accepts a hosted `video_hosted` upload OR a `video_vast` tag. Buyers pick which option they're shipping at `sync_creatives` time by aligning their manifest to the matching declaration's `format_kind` and slots.\n\nProducts MUST carry `format_ids`, `format_options`, or BOTH; at least one is required. See `format_ids` description for the dual-emission contract (same underlying declaration when both are present; SDK derives one from the other; buyers prefer `format_options` when both are present).",
+      "items": {
+        "$ref": "/schemas/core/product-format-declaration.json"
+      }
+    },
     "placements": {
       "type": "array",
       "description": "Optional array of specific placements within this product. When provided, buyers can target specific placements when assigning creatives.",
@@ -287,42 +295,78 @@
     },
     "product_card": {
       "type": "object",
-      "description": "Optional standard visual card (300x400px) for displaying this product in user interfaces. Can be rendered via preview_creative or pre-generated.",
+      "description": "Optional standard visual card for displaying this product in user interfaces (catalog browsers, dashboards, agent UIs). Distinct from `format` — product_card describes the UI rendering of the product itself, not the ad creative the product accepts. Typed inline; no format_id indirection. Receivers render the card directly from these fields.",
       "properties": {
-        "format_id": {
-          "$ref": "/schemas/core/format-id.json",
-          "description": "Creative format defining the card layout (typically product_card_standard)"
+        "image": {
+          "$ref": "/schemas/core/assets/image-asset.json",
+          "description": "Hero image for the card. Recommended ~300x400 (4:3 portrait) for the standard card layout; receivers may scale."
+        },
+        "title": {
+          "type": "string",
+          "description": "Card title (typically the product name).",
+          "maxLength": 60
+        },
+        "description": {
+          "type": "string",
+          "description": "Short descriptive blurb shown below the title.",
+          "maxLength": 200
+        },
+        "price_label": {
+          "type": "string",
+          "description": "Formatted price or pricing summary (e.g., 'From $5 CPM', 'Auction floor $0.50 CPC'). Free-text — receivers render verbatim.",
+          "maxLength": 30
         },
-        "manifest": {
-          "type": "object",
-          "description": "Asset manifest for rendering the card, structure defined by the format",
-          "additionalProperties": true
+        "cta_label": {
+          "type": "string",
+          "description": "Call-to-action button label (e.g., 'View details', 'Get proposal').",
+          "maxLength": 25
         }
       },
-      "required": [
-        "format_id",
-        "manifest"
-      ],
       "additionalProperties": true
     },
     "product_card_detailed": {
       "type": "object",
-      "description": "Optional detailed card with carousel and full specifications. Provides rich product presentation similar to media kit pages.",
+      "description": "Optional detailed card with hero + carousel + structured specifications, for rich product presentation (media-kit-style pages, full product detail views). Distinct from `format` — describes the UI rendering of the product itself, not the ad creative the product accepts. Typed inline; no format_id indirection.",
       "properties": {
-        "format_id": {
-          "$ref": "/schemas/core/format-id.json",
-          "description": "Creative format defining the detailed card layout (typically product_card_detailed)"
+        "hero_image": {
+          "$ref": "/schemas/core/assets/image-asset.json",
+          "description": "Primary hero image at the top of the detailed view."
+        },
+        "carousel_images": {
+          "type": "array",
+          "description": "Additional images for a swipeable carousel below the hero.",
+          "items": { "$ref": "/schemas/core/assets/image-asset.json" }
+        },
+        "title": {
+          "type": "string",
+          "description": "Page title (typically the product name)."
         },
-        "manifest": {
-          "type": "object",
-          "description": "Asset manifest for rendering the detailed card, structure defined by the format",
-          "additionalProperties": true
+        "description": {
+          "type": "string",
+          "description": "Full descriptive copy. Markdown allowed in client renderers that support it; otherwise treat as plain text."
+        },
+        "specifications": {
+          "type": "array",
+          "description": "Structured key/value specifications (e.g., 'Aspect ratio: 9:16', 'Duration: 30s'). Each item is a labeled fact about the product.",
+          "items": {
+            "type": "object",
+            "required": ["label", "value"],
+            "properties": {
+              "label": { "type": "string", "maxLength": 60 },
+              "value": { "type": "string", "maxLength": 200 }
+            },
+            "additionalProperties": true
+          }
+        },
+        "price_label": {
+          "type": "string",
+          "description": "Formatted price or pricing summary."
+        },
+        "cta_label": {
+          "type": "string",
+          "description": "Call-to-action button label."
         }
       },
-      "required": [
-        "format_id",
-        "manifest"
-      ],
       "additionalProperties": true
     },
     "collections": {
@@ -471,10 +515,21 @@
     "name",
     "description",
     "publisher_properties",
-    "format_ids",
     "delivery_type",
     "pricing_options",
     "reporting_capabilities"
   ],
+  "anyOf": [
+    {
+      "title": "v1 Product (named-format reference)",
+      "description": "Product references one or more named formats by structured format_id ({ agent_url, id }). The v1 path; remains supported through 4.x.",
+      "required": ["format_ids"]
+    },
+    {
+      "title": "v2 Product (inline format declarations)",
+      "description": "Product carries one or more inline ProductFormatDeclarations, each narrowing a canonical format. The v2 path introduced by RFC #3305. A single-element `format_options` array is the 90% case; multi-element arrays declare that the product accepts any of the listed format options.",
+      "required": ["format_options"]
+    }
+  ],
   "additionalProperties": true
 }
diff --git a/static/schemas/source/creative/asset-types/index.json b/static/schemas/source/creative/asset-types/index.json
index 6bbc6d0ca1..6317455faa 100644
--- a/static/schemas/source/creative/asset-types/index.json
+++ b/static/schemas/source/creative/asset-types/index.json
@@ -41,6 +41,11 @@
       "schema": "/schemas/core/assets/daast-tracker-asset.json",
       "typical_use": "Decomposed DAAST event trackers on audio formats"
     },
+    "pixel_tracker": {
+      "description": "Generic renderer-fired HTTP tracker URL — image pixel or JavaScript include — bound to a measurement event (impression, viewability, click, custom). Applies to any web-rendered canonical (image, html5, image_carousel, responsive_creative, sponsored_placement, native_*, plus non-VAST events on video_hosted/audio_hosted). Discriminated union shape with event/method enums formalized in IAB OpenRTB Native 1.2 (`imptrackers[]` / `jstracker` / `eventtrackers[]` / `link.clicktrackers[]`). Scope is RENDERER-FIRED trackers only — conversion pixels that fire on the advertiser's site post-click belong on `sync_event_sources` / `event_log`. Formats with format-specific tracker structures use `vast_tracker` (VAST `<TrackingEvents>`) or `daast_tracker` (DAAST parity) instead.",
+      "schema": "/schemas/core/assets/pixel-tracker-asset.json",
+      "typical_use": "Measurement-vendor trackers on web-rendered formats — impression/viewability/click pixels the seller's renderer fires at serve time. The bare `url` asset with `url_type: \"tracker_pixel\"` remains valid for VAST/DAAST impression URLs and for v1-compat manifests; new canonical-formats authoring SHOULD use `pixel_tracker` because it carries event + method semantics that bare URLs lose."
+    },
     "text": {
       "description": "Plain text content asset",
       "schema": "/schemas/core/assets/text-asset.json",
@@ -76,6 +81,11 @@
       "schema": "/schemas/core/assets/javascript-asset.json",
       "typical_use": "Third-party tags, custom interaction logic, analytics"
     },
+    "zip": {
+      "description": "Bundled creative archive (zip) containing index.html and supporting assets",
+      "schema": "/schemas/core/assets/zip-asset.json",
+      "typical_use": "HTML5 banner bundles with index.html + CSS + JS + images, MRAID-compatible interactive ads"
+    },
     "brief": {
       "description": "Campaign-level creative context (creative brief)",
       "schema": "/schemas/core/assets/brief-asset.json",
@@ -85,6 +95,11 @@
       "description": "Typed data feed (products, stores, jobs, etc.)",
       "schema": "/schemas/core/assets/catalog-asset.json",
       "typical_use": "Product catalogs, store locators, job feeds for dynamic creatives"
+    },
+    "card": {
+      "description": "Single card in a multi-card creative — image_carousel `cards` slot element",
+      "schema": "/schemas/core/assets/card-asset.json",
+      "typical_use": "Carousel cards (Meta-style mixed-media, Pinterest collections), Snap collection cards. Each card carries its own media (image OR video), optional headline, optional landing_page_url. The carousel format's `cards` slot is an array of card-asset values."
     }
   },
   "architecture": {
diff --git a/static/schemas/source/creative/list-creatives-response.json b/static/schemas/source/creative/list-creatives-response.json
index 677b4d8ff5..f2456e5c96 100644
--- a/static/schemas/source/creative/list-creatives-response.json
+++ b/static/schemas/source/creative/list-creatives-response.json
@@ -92,10 +92,17 @@
           },
           "assets": {
             "type": "object",
-            "description": "Assets for this creative, keyed by asset_id. Each asset value carries an `asset_type` discriminator that selects the matching asset schema.",
+            "description": "Assets for this creative, keyed by asset_id. Each slot value is either a single asset object or an array of asset objects (for slots with `min`/`max > 1`). Each asset value carries an `asset_type` discriminator that selects the matching asset schema.",
             "patternProperties": {
               "^[a-z0-9_]+$": {
-                "$ref": "/schemas/core/assets/asset-union.json"
+                "oneOf": [
+                  { "$ref": "/schemas/core/assets/asset-union.json" },
+                  {
+                    "type": "array",
+                    "items": { "$ref": "/schemas/core/assets/asset-union.json" },
+                    "minItems": 1
+                  }
+                ]
               }
             },
             "additionalProperties": true
diff --git a/static/schemas/source/creative/validate-input-request.json b/static/schemas/source/creative/validate-input-request.json
new file mode 100644
index 0000000000..f09f8be797
--- /dev/null
+++ b/static/schemas/source/creative/validate-input-request.json
@@ -0,0 +1,85 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/creative/validate-input-request.json",
+  "title": "Validate Input Request",
+  "description": "Request payload for the validate_input task. Lets buyers dry-run a creative manifest against canonical formats and/or specific products before committing to a render. Cheaper than preview_creative (no synthesis cost). Used by build_creative internally to validate inputs before producing output. For genuinely nondeterministic generative platforms (Veo/Sora/Runway-class) where predictive validation is impossible, the platform's own post-synthesis QA loop applies — validate_input is the predictable-case primitive.\n\nThe `targets[]` array is a discriminated list of validation targets, mirroring the response shape on `validate-input-result.json#target`. Each entry has a `kind` (canonical | product | third_party_format) plus a kind-specific identifier. Discriminated-by-kind on both sides eliminates a wire-shape mismatch: a previous draft used `format_ids: string[]` for canonical names alongside `product_ids: string[]`, which collided with `Product.format_ids: FormatId[]` ({agent_url, id}) — codegen would emit the same field name with two different types. Discriminated `targets[]` makes the intent explicit and codegen-clean.",
+  "type": "object",
+  "required": ["manifest"],
+  "properties": {
+    "manifest": {
+      "$ref": "/schemas/core/creative-manifest.json",
+      "description": "Creative manifest to validate."
+    },
+    "targets": {
+      "type": "array",
+      "minItems": 1,
+      "description": "Discriminated list of validation targets. Each entry mirrors the `target` shape on `validate-input-result.json` so the request/response wire shapes match exactly. Multi-target requests enable universal-creative scenarios where one manifest targets multiple sellers' format declarations in a single round-trip; the response carries one result per target in the same order.",
+      "items": {
+        "type": "object",
+        "required": ["kind", "id"],
+        "discriminator": { "propertyName": "kind" },
+        "oneOf": [
+          {
+            "title": "Canonical Format Target",
+            "properties": {
+              "kind": { "type": "string", "const": "canonical" },
+              "id": {
+                "type": "string",
+                "description": "Canonical format name from `canonical-format-kind.json` (e.g., `image`, `video_hosted`, `audio_daast`). Validators check the manifest against the canonical's parameter schema."
+              }
+            },
+            "required": ["kind", "id"]
+          },
+          {
+            "title": "Product Target",
+            "properties": {
+              "kind": { "type": "string", "const": "product" },
+              "id": {
+                "type": "string",
+                "description": "Product ID. Validators check the manifest against the product's inline `ProductFormatDeclaration` narrowing of the canonical (parameter constraints, slot requirements, platform extensions)."
+              }
+            },
+            "required": ["kind", "id"]
+          },
+          {
+            "title": "Third-Party Format Target",
+            "properties": {
+              "kind": { "type": "string", "const": "third_party_format" },
+              "id": {
+                "type": "string",
+                "format": "uri",
+                "description": "URI-form format identifier referencing a third-party format definition (e.g., `https://flashtalking.example/formats/image_300x250@sha256:...`). Validators fetch the definition (digest-pinned, cached) and validate the manifest against it."
+              }
+            },
+            "required": ["kind", "id"]
+          }
+        ]
+      }
+    }
+  },
+  "additionalProperties": true,
+  "examples": [
+    {
+      "description": "Dry-run a video manifest against canonical video_hosted and a specific Meta product in one round-trip",
+      "data": {
+        "manifest": {
+          "format_kind": "video_hosted",
+          "assets": {
+            "video_main": {
+              "asset_type": "video",
+              "url": "https://cdn.acme.example/spring-30s.mp4",
+              "duration_ms": 30000,
+              "width": 1080,
+              "height": 1920
+            }
+          },
+          "brand": { "domain": "acme.example" }
+        },
+        "targets": [
+          { "kind": "canonical", "id": "video_hosted" },
+          { "kind": "product", "id": "meta_reels_us" }
+        ]
+      }
+    }
+  ]
+}
diff --git a/static/schemas/source/creative/validate-input-response.json b/static/schemas/source/creative/validate-input-response.json
new file mode 100644
index 0000000000..9afc6710d9
--- /dev/null
+++ b/static/schemas/source/creative/validate-input-response.json
@@ -0,0 +1,16 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/creative/validate-input-response.json",
+  "title": "Validate Input Response",
+  "description": "Response payload for the validate_input task. Returns per-target validation results — one entry per format_id or product_id requested. Each result carries a `result_kind` discriminator (`validated_pass` / `validated_fail` / `unvalidatable_nondeterministic`) so callers can branch on three meaningfully different outcomes. The `predicted` field on violations carries the platform's pre-flight estimate (e.g., predicted audio duration from text-length analysis), NOT the actual output — there is no protocol state for orphaned out-of-spec artifacts. For nondeterministic generative platforms (Veo / Sora / Runway-class with `synthesis_nondeterministic: true`), the result_kind is `unvalidatable_nondeterministic` — predictive validation is impossible, the platform's post-synthesis QA loop applies on `build_creative`, and out-of-spec output never reaches this surface (instead `build_creative` returns task_failed with synthesis_failed reason).\n\nThe `ValidateInputResult` type is split into its own schema (`/schemas/creative/validate-input-result.json`) rather than inlined here because the same per-target shape is intended for reuse by adjacent async-validation surfaces (planned: per-batch result envelopes on `build_creative` async paths, and asynchronous canonical-against-product validation in `sync_creatives`). Producers that only need the synchronous batch shape today MAY treat the split as YAGNI, but the schema reuse anchors the violation/retry shape so downstream surfaces don't drift.",
+  "type": "object",
+  "required": ["results"],
+  "properties": {
+    "results": {
+      "type": "array",
+      "items": { "$ref": "/schemas/creative/validate-input-result.json" },
+      "description": "Per-target validation results."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/creative/validate-input-result.json b/static/schemas/source/creative/validate-input-result.json
new file mode 100644
index 0000000000..accb6265cf
--- /dev/null
+++ b/static/schemas/source/creative/validate-input-result.json
@@ -0,0 +1,113 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/creative/validate-input-result.json",
+  "title": "Validate Input Result",
+  "description": "Per-target result of a validate_input call. The `result_kind` discriminator (replacing the earlier boolean `ok`) lets buyers distinguish three meaningfully different outcomes:\n\n- `validated_pass` — manifest validates cleanly against the target. Buyers can submit with confidence.\n- `validated_fail` — manifest is structurally evaluable AND fails specific constraints. `violations[]` enumerates which. Buyers fix and retry.\n- `unvalidatable_nondeterministic` — predictive validation is impossible because the target's production pipeline is genuinely nondeterministic (Veo / Sora / Runway-class formats with `synthesis_nondeterministic: true`). The platform's own post-synthesis QA loop applies; outcome is unknowable until `build_creative` runs. Buyers MUST plan for the QA-loop semantics: submission may return `task_failed` with a `synthesis_failed` reason if the QA loop exhausts. There is no protocol state for orphaned out-of-spec artifacts.\n\nThe boolean `ok` field carried in earlier drafts is removed — it conflated `validated_fail` (a real validation result the buyer can act on) with `unvalidatable_nondeterministic` (a structural property of the target the buyer needs to handle differently). `validated_fail` returns `violations[]`; `unvalidatable_nondeterministic` does not (there's nothing to enumerate).\n\n**Scope of validation (normative).** `validate_input` validates **manifest structure** against the canonical / product / third-party format target — slot counts, asset types, parameter ranges, format-shape constraints. It does NOT predict the surface's per-impression rendering choice. This distinction matters for `composition_model: algorithmic` formats (`responsive_creative`, `agent_placement`) where the surface picks combinations or phrasing at delivery time: the buyer's asset pool can still be structurally validated (does it meet the count/size/length requirements?) → `validated_pass` or `validated_fail` with violations. What's unpredictable is the rendered output composition, and that's NOT what `validate_input` claims to predict. `unvalidatable_nondeterministic` is reserved for `synthesis_nondeterministic: true` cases where the production pipeline itself can't be evaluated upfront — distinct from algorithmic composition where the inputs ARE evaluable but the output rendering isn't. Buyers calling `validate_input` on an algorithmic-composition target SHOULD expect a structural verdict (pass/fail), not a rendering preview.",
+  "type": "object",
+  "required": ["target", "result_kind"],
+  "properties": {
+    "target": {
+      "type": "object",
+      "required": ["kind", "id"],
+      "properties": {
+        "kind": {
+          "type": "string",
+          "enum": ["canonical", "product", "third_party_format"]
+        },
+        "id": {
+          "type": "string",
+          "description": "Canonical format name (e.g., 'image'), product_id, or URI-form format_id."
+        }
+      },
+      "additionalProperties": true
+    },
+    "result_kind": {
+      "type": "string",
+      "enum": ["validated_pass", "validated_fail", "unvalidatable_nondeterministic"],
+      "description": "Discriminator for the validation outcome. See schema description for the three states. Replaces the earlier boolean `ok` to distinguish 'failed validation' from 'platform is nondeterministic, can't pre-validate'."
+    },
+    "violations": {
+      "type": "array",
+      "description": "When `result_kind` is `validated_fail`, the specific constraints the manifest fails to meet. MUST be absent (or empty) for `validated_pass` and `unvalidatable_nondeterministic` — neither has constraint violations to enumerate (`unvalidatable_nondeterministic` doesn't validate at all; `validated_pass` has nothing to fail).",
+      "items": {
+        "type": "object",
+        "required": ["rule", "field"],
+        "properties": {
+          "rule": {
+            "type": "string",
+            "description": "Rule name (e.g., 'duration_ms_range', 'aspect_ratio', 'max_file_size_kb')."
+          },
+          "expected": {
+            "description": "Expected value or range (e.g., '28000-32000', '9:16', 200)."
+          },
+          "predicted": {
+            "description": "Platform's pre-flight estimate for this field (NOT the actual output — there is no protocol state for orphaned out-of-spec artifacts). For TTS, this might be the predicted audio duration from text-length analysis. Helps the buyer fix the input before committing to a build."
+          },
+          "field": {
+            "type": "string",
+            "description": "Path to the violating field (e.g., 'assets.video_main.duration_ms')."
+          },
+          "retry_with": {
+            "type": "object",
+            "description": "Optional advisory adjustment hint. Platforms MAY suggest a corrected input shape; buyers MUST treat this as advisory, not authoritative.",
+            "additionalProperties": true
+          }
+        },
+        "additionalProperties": true
+      }
+    }
+  },
+  "allOf": [
+    {
+      "if": {
+        "properties": { "result_kind": { "const": "validated_pass" } },
+        "required": ["result_kind"]
+      },
+      "then": {
+        "not": { "required": ["violations"] }
+      }
+    },
+    {
+      "if": {
+        "properties": { "result_kind": { "const": "unvalidatable_nondeterministic" } },
+        "required": ["result_kind"]
+      },
+      "then": {
+        "not": { "required": ["violations"] }
+      }
+    }
+  ],
+  "additionalProperties": true,
+  "examples": [
+    {
+      "description": "Manifest fails Meta Reels product narrowing because its duration exceeds the [3000, 90000] range",
+      "data": {
+        "target": { "kind": "product", "id": "meta_reels_us" },
+        "result_kind": "validated_fail",
+        "violations": [
+          {
+            "rule": "duration_ms_range",
+            "expected": "3000-90000",
+            "predicted": 95000,
+            "field": "assets.video_main.duration_ms",
+            "retry_with": { "trim_ms_from_end": 5000 }
+          }
+        ]
+      }
+    },
+    {
+      "description": "Manifest passes canonical video_hosted (canonical doesn't constrain duration; products narrow)",
+      "data": {
+        "target": { "kind": "canonical", "id": "video_hosted" },
+        "result_kind": "validated_pass"
+      }
+    },
+    {
+      "description": "Veo generative video product is unvalidatable up-front; buyer plans for the QA-loop semantics on build_creative",
+      "data": {
+        "target": { "kind": "product", "id": "veo_generative_video_vertical_15s" },
+        "result_kind": "unvalidatable_nondeterministic"
+      }
+    }
+  ]
+}
diff --git a/static/schemas/source/creative/video-brief.json b/static/schemas/source/creative/video-brief.json
new file mode 100644
index 0000000000..44618aecff
--- /dev/null
+++ b/static/schemas/source/creative/video-brief.json
@@ -0,0 +1,71 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/creative/video-brief.json",
+  "title": "Video Brief",
+  "description": "Structured per-segment generation brief for generative video products (Veo / Sora / Runway-class). Each `segments[]` entry declares a timed prompt the synthesis pipeline turns into a continuous shot — `order`, `duration_ms`, `prompt`, optional `vo` (voiceover line) and `caption` (on-screen text). This is a *generation* brief, not a creative-direction storyboard: there is no camera direction, shot type, mood, or reference-asset attachment. Buyers wanting to direct camera, lighting, or reference-image conditioning attach a `reference-asset.json` with `purpose: \"storyboard\"` separately — that's the visual-direction surface; video-brief is the structured prompt the model receives. Renamed from earlier `scenes` to call the shape what it is (a brief, not a scene-level production document).",
+  "type": "object",
+  "required": ["segments"],
+  "properties": {
+    "segments": {
+      "type": "array",
+      "minItems": 1,
+      "description": "Ordered list of per-segment prompts that compose the generated video. The sum of `duration_ms` across segments should match the target video duration declared by the format declaration's `duration_ms_exact` / `duration_ms_range`.",
+      "items": {
+        "type": "object",
+        "required": ["order", "duration_ms", "prompt"],
+        "properties": {
+          "order": {
+            "type": "integer",
+            "minimum": 1,
+            "description": "1-indexed sequence position of this segment in the final video."
+          },
+          "duration_ms": {
+            "type": "integer",
+            "minimum": 1,
+            "description": "Duration of this segment in milliseconds."
+          },
+          "prompt": {
+            "type": "string",
+            "description": "Text prompt fed to the synthesis pipeline for this segment (subject, action, setting, mood). Renamed from earlier `description` to make explicit that this is a generation prompt — not a description-of-finished-content."
+          },
+          "vo": {
+            "type": "string",
+            "description": "Voiceover line for this segment (optional)."
+          },
+          "caption": {
+            "type": "string",
+            "description": "On-screen caption text for this segment (optional)."
+          }
+        },
+        "additionalProperties": true
+      }
+    }
+  },
+  "additionalProperties": true,
+  "examples": [
+    {
+      "segments": [
+        {
+          "order": 1,
+          "duration_ms": 3000,
+          "prompt": "Sunset beach, brand logo overlay top-left, warm cinematic tone",
+          "vo": "Welcome to summer with Acme",
+          "caption": "Summer Sale Now"
+        },
+        {
+          "order": 2,
+          "duration_ms": 4000,
+          "prompt": "Product close-up — limited-edition sneakers, slow zoom on stitching",
+          "vo": "Limited edition. Hand-crafted.",
+          "caption": "Up to 50% Off"
+        },
+        {
+          "order": 3,
+          "duration_ms": 3000,
+          "prompt": "Logo end-card on solid brand-color background with CTA button overlay",
+          "caption": "Shop Now"
+        }
+      ]
+    }
+  ]
+}
diff --git a/static/schemas/source/enums/error-code.json b/static/schemas/source/enums/error-code.json
index 9caf0e0183..618612b688 100644
--- a/static/schemas/source/enums/error-code.json
+++ b/static/schemas/source/enums/error-code.json
@@ -73,7 +73,14 @@
     "AGENT_SUSPENDED",
     "AGENT_BLOCKED",
     "CREDENTIAL_IN_ARGS",
-    "ACTION_NOT_ALLOWED"
+    "ACTION_NOT_ALLOWED",
+    "FORMAT_PROJECTION_FAILED",
+    "FORMAT_DECLARATION_DIVERGENT",
+    "FORMAT_DECLARATION_V1_AMBIGUOUS",
+    "FORMAT_CAPABILITY_UNRESOLVED",
+    "FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE",
+    "PIXEL_TRACKER_LOSSY_DOWNGRADE",
+    "PIXEL_TRACKER_UPGRADE_INFERRED"
   ],
   "enumDescriptions": {
     "INVALID_REQUEST": "Request is malformed, missing required fields, or violates schema constraints. Recovery: correctable (check request parameters and fix).",
@@ -144,7 +151,14 @@
     "AGENT_SUSPENDED": "The calling buyer agent's commercial relationship with the seller is temporarily paused — the agent is onboarded but currently suspended. Sibling to `ACCOUNT_SUSPENDED` (account-wide) and `CAMPAIGN_SUSPENDED` (per-plan) but scoped to the agent-relationship axis (orthogonal to any specific account on that agent). The code itself is the discriminator — it does NOT carry an `error.details` payload (mirroring `BILLING_NOT_PERMITTED_FOR_AGENT`'s discriminator-by-code pattern), and MUST NOT carry per-agent commercial state (rate cards, payment terms, credit limit, billing entity, contact channels) since full disclosure of per-agent state in a single probe is a per-agent oracle. Cross-tenant onboarding oracle clamp + channel-coverage requirements (response shape, HTTP/A2A/MCP status, headers, side effects, observability, latency parity, retry-counter side channel) are normative in error-handling.mdx Per-Agent Authorization Gate; this description does not restate them to avoid drift. Recovery: terminal (re-onboarding may resolve the suspension; the agent MUST surface to a human at the buyer rather than auto-retrying — the agent cannot unilaterally lift a suspension, and re-attempts only reinforce the gate).",
     "AGENT_BLOCKED": "The calling buyer agent's commercial relationship with the seller is permanently denied — the agent is blocked. Sibling to `AGENT_SUSPENDED` on the agent-relationship axis but with no recovery path (a suspension may lift via re-onboarding; a block does not). The code itself is the discriminator — same posture as `AGENT_SUSPENDED`: no `error.details` payload, no per-agent commercial state, cross-tenant onboarding oracle clamp + channel-coverage requirements normative in error-handling.mdx Per-Agent Authorization Gate. Recovery: terminal (no autonomous recovery — the agent MUST surface to a human at the buyer; relationships are reinstated only through offline operator action with the seller, not via any seller-callable AdCP task).",
     "CREDENTIAL_IN_ARGS": "The seller detected a buyer-principal credential placed in request args (top-level, in `context`, in `ext`, or any other nested location in the task payload) instead of arriving on the transport's authentication channel. Buyer-principal credentials MUST arrive on the transport's authentication channel (`Authorization: Bearer` per RFC 6750 §2 for HTTP, RFC 9421 signature headers for signed requests, MCP/A2A authentication framing per RFC 9728 §3) and MUST NOT travel inside the task payload. Distinct from `AUTH_REQUIRED` (no credentials presented or presented credentials rejected on the transport channel) and `PERMISSION_DENIED` (authenticated caller not authorized for the action). Distinct from the receiver-side credentials carried in `push_notification_config.authentication.credentials`, which configure the seller's webhook callback authentication and are not buyer-principal credentials — those are an explicit carve-out and MUST NOT trigger this code. Sellers SHOULD reject credential-in-args under AdCP 3.1; the requirement upgrades to MUST 90 days after the 3.1 publication date. Recovery: terminal — the agent MUST NOT auto-retry. Auto-retry against this code re-logs the credential on each attempt across the seller's request logs, observability stack, and any LLM-context surfaces in the buyer-side recovery loop, exactly the prompt-injection exfiltration surface that motivated the rule. Wire placement. Sellers MUST flip transport-level failure markers (HTTP 4xx, MCP `isError: true`, A2A `failed`) and populate both layers per the two-layer model in `error-handling.mdx#envelope-vs-payload-errors-the-two-layer-model`. The code itself is the discriminator; no `error.details` shape is defined, and `error.field` MUST NOT echo the offending credential value or any prefix of it (e.g., `\"Bearer ey...\"`) — the path that triggered detection is sufficient (e.g., `request.access_token`, `request.context.credentials`, `request.ext.api_key`). `error.message` MUST be generic and MUST NOT contain credential material. Sellers MUST drop the smuggled credential from logs, audit rows, and observability spans before persisting the rejection — the rejection itself is otherwise an exfiltration surface.",
-    "ACTION_NOT_ALLOWED": "The requested mutation maps to an action that is not currently available on this media buy. Sellers MUST populate `error.details` with `attempted_action` (the `media_buy_valid_action` value the request maps to), `reason` (an `action-not-allowed-reason` value: `wrong_status`, `not_supported_on_product`, `not_supported_on_buy`, or `mode_mismatch`), and `currently_available_actions` (echo of the buy's resolved `available_actions[]` so the buyer SDK can offer recovery without a separate get_media_buys round-trip). Recovery: correctable when `reason` is `wrong_status` (wait for or transition to an allowed status) or `mode_mismatch` (re-issue through the appropriate flow). Terminal-for-this-buy when `reason` is `not_supported_on_product` or `not_supported_on_buy` — buyers select a different product or renegotiate buy terms."
+    "ACTION_NOT_ALLOWED": "The requested mutation maps to an action that is not currently available on this media buy. Sellers MUST populate `error.details` with `attempted_action` (the `media_buy_valid_action` value the request maps to), `reason` (an `action-not-allowed-reason` value: `wrong_status`, `not_supported_on_product`, `not_supported_on_buy`, or `mode_mismatch`), and `currently_available_actions` (echo of the buy's resolved `available_actions[]` so the buyer SDK can offer recovery without a separate get_media_buys round-trip). Recovery: correctable when `reason` is `wrong_status` (wait for or transition to an allowed status) or `mode_mismatch` (re-issue through the appropriate flow). Terminal-for-this-buy when `reason` is `not_supported_on_product` or `not_supported_on_buy` — buyers select a different product or renegotiate buy terms.",
+    "FORMAT_PROJECTION_FAILED": "Non-fatal advisory raised when a v1 named format on a product cannot be projected to a canonical-formats `ProductFormatDeclaration` via the resolution order in `v1-canonical-mapping.json` (explicit `canonical` field → format_id_glob → structural match → fail-closed). The product is still valid on the v1 path; only the v2 `format_options` projection failed. Primarily a **consumer-SDK concern** — the seller didn't fail; the consumer-side SDK couldn't project on their behalf. `error.field` MUST point at the offending product (e.g., `products[3].format_ids[0]`); `error.details` SHOULD carry `{ format_id, product_id, resolution_failure: \"no_explicit_canonical\" | \"no_registry_match\" | \"no_structural_match\" }` so buyer SDKs can route remediation (suggest the seller add an explicit `canonical` field, or file a registry PR).\n\n**Surface placement (normative).** SDKs that detect this on consumption MUST augment the response's `errors[]` array with an entry carrying `source: \"sdk\"`, `sdk_id: \"<package>@<version>\"`, `code: \"FORMAT_PROJECTION_FAILED\"`, and the field+details described above. This is the single mandated surface — logger-only is insufficient and a separate lint-output channel is NOT acceptable (AdCP is a multi-hop agent network; warnings need to propagate across hops or each hop has to re-detect locally). Sellers MAY emit this code on their own response when they self-detect a non-projectable format on emit; producer-emitted entries omit `source` (or set `source: \"producer\"`). The response stays 200/success regardless of who emits; this is non-fatal.\n\n**Multi-hop deduplication.** Each hop that detects the same condition SHOULD deduplicate by `(code, field)` rather than re-emit. The existing entry's `sdk_id` identifies which earlier processor saw it first; downstream SDKs SHOULD NOT add a second entry for the same `(code, field)` pair unless they have materially different `error.details` (e.g., a different `resolution_failure` reason from a different registry version).\n\nRecovery: correctable (seller-side action — add explicit `canonical` field on the v1 format file, contribute a v1-canonical-mapping registry entry, or author a v2 `ProductFormatDeclaration` with `v1_format_ref` linking back). See canonical-formats.mdx 'Dual emission and v2↔v1 projection' for the full rules.",
+    "FORMAT_DECLARATION_DIVERGENT": "Non-fatal advisory raised when a product carries BOTH `format_ids` (v1) AND `format_options` (v2) and the two disagree (different canonical, different dimensions, different orientation) after projection. The producer's contract is that both shapes MUST refer to the same underlying declaration; divergence is a producer bug.\n\nEither side MAY emit this code: a SELLER may self-detect on emit (own producer bug; rare), or more commonly a consumer-SDK detects on consumption. SDKs MUST prefer `format_options` (the richer surface) when both are present and MUST surface the divergent product so it's observable rather than silently picked-one-and-dropped-other. Hard-failing the entire `get_products` response is discouraged — it punishes downstream buyers for the producer bug.\n\n**Surface placement (normative).** Same single-surface mandate as `FORMAT_PROJECTION_FAILED`: SDKs that detect this on consumption MUST augment the response's `errors[]` array with an entry carrying `source: \"sdk\"`, `sdk_id: \"<package>@<version>\"`, `code: \"FORMAT_DECLARATION_DIVERGENT\"`, and the field+details described below. Logger-only is insufficient; lint-output channels are NOT acceptable as the surface (the multi-hop agent network needs warnings to propagate across SDK boundaries via the wire response).\n\n`error.field` MUST point at the offending product; `error.details` SHOULD carry `{ product_id, format_ids, format_options_summary, divergence_reason }` so buyer SDKs can flag the producer for follow-up.\n\n**Multi-hop deduplication.** Each hop that detects the same divergence SHOULD deduplicate by `(code, field)` rather than re-emit; the existing entry's `sdk_id` identifies which earlier processor saw it first.\n\nRecovery: correctable but seller-side — buyer can't fix divergent declarations, only flag them.",
+    "FORMAT_DECLARATION_V1_AMBIGUOUS": "Non-fatal advisory raised when an SDK detects that a product's v2 declaration cannot be unambiguously projected back to a single v1 named format because the v1-canonical-mapping registry has only family-level structural entries for this canonical (no invertible `format_id_glob` literal). The family is known (e.g., 'this is a video_vast'); the specific v1 named format isn't pickable mechanically. Distinct from `FORMAT_PROJECTION_FAILED` (registry-coverage gap, correctable by adding a registry entry) — ambiguity is structural: the family is defined but a specific format can't be picked without seller assertion.\n\nSurface placement: same single-mandate as `FORMAT_PROJECTION_FAILED` and `FORMAT_DECLARATION_DIVERGENT` — SDKs MUST augment the response's `errors[]` array with an entry carrying `source: \"sdk\"`, `sdk_id`, `code: \"FORMAT_DECLARATION_V1_AMBIGUOUS\"`, `field` pointing at the offending declaration, and `error.details` SHOULD carry `{ format_kind, registry_matches: [<list of structural entries that matched at family level>], product_id }` so adopters can see why the inversion was ambiguous.\n\n**SDKs MUST NOT synthesize a v1_format_ref** in this case (or any other case). v1↔v2 explicit pairing is seller-asserted only — SDKs encountering family-only registry matches MUST treat the v2 declaration as v1-unreachable and surface this code rather than invent a plausible v1 format_id. The seller's path: author `v1_format_ref` on the v2 declaration to disambiguate (the authoritative pairing per `v1-canonical-mapping.json` resolution step 1), or accept that v1-only buyers won't see this product. Recovery: correctable but seller-side — buyer can't disambiguate without the seller's assertion.",
+    "FORMAT_CAPABILITY_UNRESOLVED": "Non-fatal advisory raised when a placement in `adagents.json` (or any consumer of `placement-definition.json`) carries `format_options[].capability_id` referencing a `capability_id` that does NOT exist in the file's top-level `formats[]`. The reference is broken — the publisher's catalog claims the placement accepts a capability that isn't declared.\n\n**Resolution scope is same-file only.** Cross-file `capability_id` lookup is not supported by design (closes off capability_id squatting across publisher boundaries — a malicious file cannot reference another publisher's capability_id and claim its narrowing). Buyer SDKs MUST fail closed for the placement (drop the format from the placement's accepted format set) and MUST surface this code rather than silently dropping or guessing what the publisher meant.\n\nSurface placement: same single-mandate as the other FORMAT_* codes — SDKs that detect on consumption MUST augment the response's `errors[]` with `source: \"sdk\"`, `sdk_id`, `code: \"FORMAT_CAPABILITY_UNRESOLVED\"`, `field` pointing at the offending placement (e.g., `placements[2].format_options[1].capability_id`), and `error.details` SHOULD carry `{ placement_id, capability_id, declared_capabilities: [<list of capability_ids actually in formats[]>] }` so the publisher can fix.\n\nRecovery: correctable but publisher-side — buyer can't fix; publisher either declares the missing capability in `formats[]` or removes the reference from the placement.",
+    "FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE": "Non-fatal advisory raised when a v2 declaration carries `params.sizes[]` with N entries but only M v1_format_ref entries (M < N). The seller has asserted some v1 named formats but not enough to cover all declared sizes — v1-only buyers see partial coverage. Emitted **alongside** the partial v1 emission (NOT in place of it): the product still appears on the v1 wire under the M sizes the seller covered; this code tells v1-aware downstream agents that N-M sizes were dropped from the projection.\n\nSurface placement: SDKs that detect on emission OR consumption MUST augment the response's `errors[]` with `source: \"sdk\"` (or `\"producer\"` if the seller self-detects on emit), `sdk_id`, `code: \"FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE\"`, `field` pointing at the offending declaration, and `error.details` SHOULD carry `{ product_id, declared_sizes: [{w,h}, …], covered_sizes: [{w,h}, …], dropped_sizes: [{w,h}, …] }` so buyer agents see which sizes were lost.\n\n**SDKs MAY (non-normative) fan out automatically** by catalog lookup — for each entry in `sizes[]` lacking a corresponding `v1_format_ref`, the SDK consults the AAO catalog for the per-size v1 named format (e.g., for `{width: 728, height: 90}` look up `display_728x90_image`) and emits it under `format_ids[]`. This is opt-in (requires catalog access); when SDKs fan out, they SHOULD still emit this code as a transparency advisory so downstream consumers know the v1 emit was synthesized rather than seller-asserted.\n\nRecovery: warning — non-fatal, no retry. Seller fix: add `v1_format_ref[]` entries for the missing sizes.",
+    "PIXEL_TRACKER_LOSSY_DOWNGRADE": "Non-fatal advisory raised when a 3.1 buyer SDK downgrades a `pixel_tracker` asset to the v1 `{asset_type: url, url_type: tracker_pixel}` shape for a 3.0.x seller that doesn't recognize the new asset type. The URL is still emitted on the wire and the seller will fire it as a tracker pixel; what's lost is the event/method discrimination.\n\nDowngrade rules (normative):\n- `event: impression` + `method: img` → no loss; emit as `{asset_type: url, url_type: tracker_pixel, url, asset_id: impression_tracker}`\n- `event: viewable_mrc_50` / `viewable_mrc_100` / `viewable_video_50` / `audible_video_complete` → emit with `asset_id: viewability_tracker`; advisory `lost_event: <variant>` (specific viewability variant collapses to a single v1 slot)\n- `event: click` → emit with `asset_id: click_tracker`; no meaningful loss\n- `event: custom, custom_event_name: X` → emit with `asset_id: impression_tracker` (default tracker_pixel fires on impression); advisory `lost_event: \"custom\"`, `lost_custom_event_name: X` (custom event timing collapses to impression timing)\n- `method: js` → emit unchanged shape (url, url_type:tracker_pixel); advisory `lost_method: \"js\"` (v1 seller will fire as HTTP GET; the URL is hit and any counter-based measurement increments, but the response body won't execute as JS — measurement that depends on JS execution, e.g., OMID-style verification, viewability observers, cross-domain cookie setters, won't work. Simple counter pixels still work.)\n\nSurface: SDK that performs the downgrade MUST augment the response's `errors[]` with `source: \"sdk\"`, `sdk_id`, `code: \"PIXEL_TRACKER_LOSSY_DOWNGRADE\"`, `field` pointing at the affected manifest asset path, and `error.details` SHOULD carry `{ asset_id, original_event, original_method, original_custom_event_name (if present), downgrade_target: \"url+tracker_pixel\", lost_fields: [<list>] }`. One advisory per downgraded asset; SDKs SHOULD NOT collapse multiple downgrades into a single advisory entry — per-asset details let the buyer's measurement-plan owner decide whether each loss is tolerable.\n\nRecovery: warning — non-fatal, no retry. Buyer-side decision: accept the loss (most simple counter pixels survive), or fail the buy and route to a 3.1-capable seller. Seller-side fix: upgrade to 3.1 and accept `pixel_tracker` natively.",
+    "PIXEL_TRACKER_UPGRADE_INFERRED": "Non-fatal advisory raised when a 3.1 buyer SDK upgrades a v1 `{asset_type: url, url_type: tracker_pixel}` to a `pixel_tracker` asset by INFERRING the event and method from the v1 asset_id and conventional defaults. The inference is structural — the SDK doesn't have explicit event/method values, only the v1 asset_id hint and `url_type: tracker_pixel` (which implies `method: img` by default).\n\nInference rules (normative):\n- `asset_id: impression_tracker` → `event: impression, method: img`\n- `asset_id: viewability_tracker` → `event: viewable_mrc_50, method: img` (50% is the most common default; specific viewability variant cannot be recovered from v1 shape)\n- `asset_id: click_tracker` → `event: click, method: img`\n- `asset_id: <other>` → `event: custom, custom_event_name: <original asset_id>, method: img`\n\nSurface: SDK MUST augment the response's `errors[]` with `code: \"PIXEL_TRACKER_UPGRADE_INFERRED\"`, `field` pointing at the upgraded asset path, and `error.details` SHOULD carry `{ asset_id, inferred_event, inferred_method, inference_basis: \"asset_id_convention\" | \"default\" }`. Buyer agents reading the response can re-prompt the seller for explicit values if precise measurement matters.\n\nRecovery: warning — non-fatal, no retry. Seller-side: upgrade emit path to ship pixel_tracker shape directly when 3.1-capable; until then, conventional asset_id values give the SDK enough signal to upgrade without losing critical semantics."
   },
   "enumMetadata": {
     "$comment": "Structured recovery classification and remediation hints for each error code. SDKs MUST consume this block instead of parsing 'Recovery: X' from enumDescriptions prose. Each entry is { recovery, suggestion }. recovery is one of: correctable (caller can fix and retry), transient (retry with backoff), terminal (no autonomous recovery - operator intervention required). enumDescriptions is retained for human readability and will continue to carry the canonical narrative; the recovery classification embedded in that prose is normative and MUST match the value here.",
@@ -423,6 +437,34 @@
     "ACTION_NOT_ALLOWED": {
       "recovery": "correctable",
       "suggestion": "branch on error.details.reason: for wrong_status, wait for or transition to a status listed under the action's allowed_statuses; for mode_mismatch, this is a flow switch (not a retry against update_media_buy) — re-issue through the flow named in available_actions[<action>].mode (call create_proposal/finalize_proposal for requires_proposal; await the seller's webhook for requires_approval); for not_supported_on_product or not_supported_on_buy, do not retry — the action is unavailable on this buy and buyer must select a different product or renegotiate"
+    },
+    "FORMAT_PROJECTION_FAILED": {
+      "recovery": "correctable",
+      "suggestion": "advisory — seller-side fix needed: ask the seller to add an explicit `canonical` field on the v1 format declaration, or contribute a registry entry (format_id_glob or structural match) to v1-canonical-mapping.json. Do not auto-retry; the product is still valid on the v1 path"
+    },
+    "FORMAT_DECLARATION_DIVERGENT": {
+      "recovery": "correctable",
+      "suggestion": "advisory — seller-side fix needed: producer is emitting disagreeing format_ids and format_options for the same product. Buyer SDK SHOULD prefer format_options and surface the divergent product to operators; do not auto-retry"
+    },
+    "FORMAT_DECLARATION_V1_AMBIGUOUS": {
+      "recovery": "correctable",
+      "suggestion": "advisory — seller-side fix needed: the v2 declaration's canonical has only family-level structural registry entries (no invertible literal). Seller MUST author v1_format_ref on the v2 declaration to disambiguate; SDKs MUST NOT synthesize. Do not auto-retry"
+    },
+    "FORMAT_CAPABILITY_UNRESOLVED": {
+      "recovery": "correctable",
+      "suggestion": "advisory — publisher-side fix needed: a placement's `format_options[].capability_id` references a `capability_id` that does not exist in this file's top-level `formats[]`. Buyer SDK MUST fail closed for that placement (drop the format from the placement's accepted set) and surface this code. Publisher fix: either declare the missing capability in `formats[]` or remove the reference from the placement. Do not auto-retry"
+    },
+    "FORMAT_DECLARATION_V1_LOSSY_MULTI_SIZE": {
+      "recovery": "correctable",
+      "suggestion": "advisory — emitted alongside the partial v1 emission, NOT in place of it: the v2 declaration carries `params.sizes[]` with N entries but only M v1_format_ref entries (M < N), so v1 buyers see partial size coverage on the product. Seller-side fix: add v1_format_ref entries for the missing sizes. SDK MAY (non-normative) fan out automatically by catalog lookup. Non-fatal — do not auto-retry"
+    },
+    "PIXEL_TRACKER_LOSSY_DOWNGRADE": {
+      "recovery": "correctable",
+      "suggestion": "advisory — emitted alongside the v1 downgrade emission: SDK collapsed a pixel_tracker asset to v1 `{asset_type: url, url_type: tracker_pixel}` for a seller that doesn't support pixel_tracker natively. The URL still fires; what's lost is in `error.details.lost_fields` (event variant, method:js execution context, or custom event timing). Buyer decision: accept the loss (most counter pixels survive), or fail the buy and route to a 3.1-capable seller. Non-fatal — do not auto-retry"
+    },
+    "PIXEL_TRACKER_UPGRADE_INFERRED": {
+      "recovery": "correctable",
+      "suggestion": "advisory — emitted when a 3.1 SDK upgrades a v1 url+tracker_pixel asset to pixel_tracker by inferring event and method from asset_id conventions. The inference may not match the buyer's original intent; check `error.details.inferred_event` / `inferred_method` and re-prompt the seller for explicit values if precise measurement matters. Non-fatal — do not auto-retry"
     }
   }
 }
\ No newline at end of file
diff --git a/static/schemas/source/formats/canonical/_base.json b/static/schemas/source/formats/canonical/_base.json
new file mode 100644
index 0000000000..3a222c922b
--- /dev/null
+++ b/static/schemas/source/formats/canonical/_base.json
@@ -0,0 +1,144 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/_base.json",
+  "title": "Canonical Format Base",
+  "description": "Shared parameter fields that apply across canonical formats. Each canonical format extends this base with format-specific parameters (dimensions, durations, codecs, slot constraints).",
+  "type": "object",
+  "properties": {
+    "experimental": {
+      "type": "boolean",
+      "default": false,
+      "description": "When true, this canonical (or a seller's specific narrowing of it) may not work as declared — adopters SHOULD have a v1 fallback ready and SHOULD NOT route production budget without testing. Same semantics as `experimental` on protocols: 'this is shipping but may break, evolve, or fail.' Buyers reading `experimental: true` SHOULD prefer the v1 path when a v1 fallback exists for the same product (via `format_ids` on the parent product or via the v2 declaration's `v1_format_ref`).\n\nThree drivers of `experimental: true`:\n1. **Spec maturity** — the canonical's tracking model or parameter shape is still being settled (`agent_placement`'s tracking macros, `sponsored_placement`'s per-adapter contracts, `responsive_creative`'s algorithmic composition).\n2. **Adopter runtime gap** — the seller has declared the canonical in their catalog but their runtime doesn't yet honor it cleanly.\n3. **Custom shapes** — `format_kind: \"custom\"` is inherently experimental until the working group promotes a `format_shape` to a first-class canonical.\n\nReplaces the earlier `status` enum (`stable | preview | deprecated`) + `runtime_status` enum (`stable | preview | declared_only`) — two axes with subtle overlap. The single boolean is what buyers actually care about: do I treat this as production-stable or as 'try at my own risk.' Sellers SHOULD set `experimental: true` on canonicals or product declarations that aren't yet production-ready, regardless of which axis (spec, runtime, custom) drives the experimentation. The 6 IAB/VAST/DAAST re-encodings (`image`, `display_tag`, `video_hosted`, `video_vast`, `audio_hosted`, `audio_daast`) default to non-experimental at the canonical level; sellers MAY still mark a specific product declaration experimental (e.g., a beta runtime path for an existing product)."
+    },
+    "deprecated": {
+      "type": "boolean",
+      "default": false,
+      "description": "When true, this canonical (or a seller's specific narrowing of it) is going away. Existing adopters are supported through the deprecation cycle; new adoption is discouraged. Pair with `migration_target_version` to indicate when the canonical is expected to be removed. Distinct from `experimental`: an experimental canonical may stabilize and stop being experimental; a deprecated canonical is on a sunset path."
+    },
+    "v1_translatable": {
+      "type": "boolean",
+      "default": true,
+      "description": "Whether this canonical has any v1 named-format equivalent. `true` (default) — the canonical is structurally expressible as one or more v1 named formats (IAB display sizes, VAST tags, DAAST tags, etc.); v1→v2 projection via `v1-canonical-mapping.json` is meaningful. `false` — the canonical is inherently new in v2 and has no v1 form; v1's `list_creative_formats` couldn't express it because the underlying concept (algorithmic surface composition, AI-surface mentions, retail-media catalog placements, multi-card carousels) didn't exist as a v1 named-format archetype.\n\nLets SDKs distinguish two failure modes that today look identical: (a) the registry hasn't covered this canonical yet (correctable — seller adds explicit `canonical` field or files a registry entry) vs (b) no v1 path is possible (informational — buyer needs v2-aware consumption, or seller declares `canonical_formats_only: true` on the product declaration). SDKs encountering `v1_translatable: false` on a canonical SHOULD NOT emit `FORMAT_PROJECTION_FAILED` (which signals registry-coverage gap) — instead surface the inherent v1-unreachability as a different diagnostic or skip silently. The 4 inherently-v2 canonicals at 3.1 GA: `image_carousel`, `sponsored_placement`, `responsive_creative`, `agent_placement`."
+    },
+    "since_version": {
+      "type": "string",
+      "pattern": "^[1-9]\\d*\\.(0|[1-9]\\d*)$",
+      "description": "AdCP MAJOR.MINOR version that introduced this canonical (e.g., '3.1', '3.2'). Lets adopters reason about minimum protocol version requirements when consuming a format declaration. Patch precision is intentionally rejected — canonicals are introduced at minor-version boundaries."
+    },
+    "migration_target_version": {
+      "type": "string",
+      "pattern": "^[1-9]\\d*\\.(0|[1-9]\\d*)$",
+      "description": "AdCP MAJOR.MINOR version by which the working group expects this canonical to stabilize, surface a breaking revision, or (when `deprecated: true`) be removed. Patch precision is intentionally rejected — canonicals shift at minor-version boundaries. Absence signals 'no specific target' (omit the field rather than use a placeholder like 'unknown')."
+    },
+    "composition_model": {
+      "type": "string",
+      "enum": ["deterministic", "algorithmic"],
+      "description": "Whether the surface composes deterministically (buyer can predict per-slot rendering — sponsored_placement, image, video) or algorithmically (surface chooses combinations or phrasing — responsive_creative, agent_placement)."
+    },
+    "provenance_required": {
+      "type": "boolean",
+      "description": "When true, the product rejects unsigned synthesized assets. Builders calling build_creative MUST attach a C2PA-compatible provenance manifest attributing synthesis to the creative agent."
+    },
+    "platform_extensions": {
+      "type": "array",
+      "description": "Platform-specific extensions narrowing the canonical (pixel ID shapes, conversion event taxonomies, platform-specific CTAs/destinations). Each extension is a URI+digest reference resolved against the bundled `extensions` map in get_products responses or fetched directly.\n\n**Collision precedence (normative).** When two or more `platform_extensions[]` entries on the same declaration extend the same target (e.g., both extend `tracking`) with overlapping field names, **array order is authoritative — later entries override earlier ones on a per-field basis** (last-in-array-wins). SDKs MUST surface the overlap via the `errors[]` array on the `get_products` response with a structured code (`FORMAT_DECLARATION_DIVERGENT` is appropriate when the overlap appears across dual-emitted shapes; a producer-self-emitted overlap on a single declaration SHOULD use the same code with `error.details: { collision_kind: \"platform_extension_field\", target, overlapping_fields, winning_extension_uri }`). Producers SHOULD avoid the collision by emitting one extension per target or by partitioning fields across extensions; the deterministic precedence is for last-resort consistency across SDK implementations, not a sanctioned merging strategy.",
+      "items": { "$ref": "/schemas/core/platform-extension-ref.json" }
+    },
+    "synthesis_nondeterministic": {
+      "type": "boolean",
+      "description": "When true, the format's production pipeline is genuinely nondeterministic — the platform cannot guarantee that synthesis from a given input set produces in-spec output. Veo / Sora / Runway-class generative video, and other AI-synthesis flows where output dimensions, duration, or quality vary per run. Implies a different validation contract: predictive `validate_input` is impossible; the platform's own post-synthesis QA loop applies; if the QA loop exhausts without producing a valid artifact, `build_creative` returns task_failed with a synthesis_failed reason. Distinct from `composition_model` (which describes how the surface composes per-slot rendering, not whether synthesis is deterministic). When false or absent, the format's production is predictable enough that `validate_input` can predict output properties from input properties.\n\n**Compatibility with `asset_source` / `item_production_model`**: `synthesis_nondeterministic: true` MAY pair with any of `seller_pre_rendered_from_brief`, `seller_human_designed`, or `agent_synthesized` (the QA loop is concept-level, not source-specific — 'seller renders from brief but each retry differs' is just as nondeterministic as Veo). It MUST NOT pair with `buyer_uploaded` (the buyer ships pre-rendered bytes; there's no synthesis step to be nondeterministic about). It MUST NOT pair with `publisher_host_recorded` (the publisher's host produces a deterministic-from-script output even if the human voice varies). When `synthesis_nondeterministic: true` is set with an incompatible source, validators SHOULD reject with a structured error.",
+      "default": false
+    },
+    "slots": {
+      "type": "array",
+      "description": "Programmatic declaration of which canonical asset_group_id slots a manifest targeting this format must (or may) populate. Lets SDK codegen and validators enumerate expected slots without parsing the format's prose description. Each entry references an asset_group_id from the canonical vocabulary registry, paired with an `asset_type` so the validator knows which asset schema to apply. Format-level narrowing parameters that apply across all slots (e.g., flat `headline_max_chars` on responsive_creative) may also live on the format declaration; per-slot constraints (a specific slot's `max_chars` or `max_size_kb`) live on the slot entry.",
+      "items": {
+        "type": "object",
+        "required": ["asset_group_id", "asset_type"],
+        "properties": {
+          "asset_group_id": {
+            "type": "string",
+            "description": "Canonical asset_group_id from /schemas/core/asset-group-vocabulary.json. Non-canonical IDs are valid but trigger soft warnings."
+          },
+          "asset_type": {
+            "type": "string",
+            "enum": ["image", "video", "audio", "text", "markdown", "url", "html", "css", "javascript", "vast", "daast", "webhook", "brief", "catalog", "zip", "card", "object"],
+            "description": "Discriminator selecting the asset schema this slot accepts. SDK codegen uses this to type the slot value. `card` is the multi-card carousel element type (see card-asset.json). `object` is a last-resort fallback for structured non-asset inputs that don't fit any primitive asset_type — prefer specific types whenever possible."
+          },
+          "required": {
+            "type": "boolean",
+            "description": "Whether this slot is required for a valid manifest.",
+            "default": false
+          },
+          "min": {
+            "type": "integer",
+            "minimum": 0,
+            "description": "Minimum count for repeatable / pool slots."
+          },
+          "max": {
+            "type": "integer",
+            "minimum": 1,
+            "description": "Maximum count for repeatable / pool slots."
+          },
+          "max_chars": {
+            "type": "integer",
+            "minimum": 1,
+            "description": "Per-slot character limit. Valid only when `asset_type` is `text`, `markdown`, or `brief`. Mutually exclusive with `max_size_kb` (which applies to binary asset types). Schema enforces via if/then so a producer can't set both on the same slot."
+          },
+          "max_size_kb": {
+            "type": "integer",
+            "minimum": 1,
+            "description": "Per-slot file size limit in kilobytes. Valid only when `asset_type` is `image`, `video`, `audio`, or `zip`. Mutually exclusive with `max_chars` (which applies to text asset types). Schema enforces via if/then so a producer can't set both on the same slot."
+          },
+          "description": {
+            "type": "string",
+            "description": "Human-readable description of what the slot expects from the buyer."
+          },
+          "consumed_for_production": {
+            "type": "boolean",
+            "default": false,
+            "description": "Dispatch hint for `build_creative` and v1↔v2 wire translators: when `true`, the slot's value is consumed as INPUT to a production step (host-read script, brief copy fed to generative synthesis, catalog feed driving per-SKU rendering) and is not rendered verbatim. When `false` (default), the slot's value is rendered verbatim on the placement (image bytes, video file, display tag).\n\nMotivates the v1↔v2 dispatch table: pre-v2 buyers shipped production-consumed inputs separately in a `inputs` map on the build_creative request; v2 collapses inputs and rendered assets into a single `assets` map keyed by `asset_group_id`. SDK translators between v1 and v2 use this flag per canonical to know which assets in the v2 manifest map back to v1 `inputs` vs v1 `assets`. Without the per-slot flag the dispatch table lives in adopter code and every SDK gets it slightly different.\n\nProducers SHOULD set this explicitly on slots whose consumption pattern isn't obvious (host-read scripts on `audio_hosted`, briefs on generative `video_hosted`, catalog feeds on `sponsored_placement`). For canonicals where every slot is render-verbatim (`image`, `display_tag`, `video_vast`), the default `false` is sufficient and the flag MAY be omitted."
+          }
+        },
+        "additionalProperties": true,
+        "allOf": [
+          {
+            "$comment": "max_chars is valid only for text-shaped asset types; max_size_kb is valid only for binary asset types. A slot MUST NOT carry both; the type-appropriate one is enforced via if/then.",
+            "if": {
+              "properties": { "asset_type": { "enum": ["text", "markdown", "brief"] } },
+              "required": ["asset_type"]
+            },
+            "then": { "not": { "required": ["max_size_kb"] } }
+          },
+          {
+            "if": {
+              "properties": { "asset_type": { "enum": ["image", "video", "audio", "zip"] } },
+              "required": ["asset_type"]
+            },
+            "then": { "not": { "required": ["max_chars"] } }
+          },
+          {
+            "$comment": "Non-size asset types (url, catalog, html, css, javascript, webhook, daast, vast, card, object) reject both — there's no defined per-slot size semantics on those.",
+            "if": {
+              "properties": { "asset_type": { "enum": ["url", "catalog", "html", "css", "javascript", "webhook", "daast", "vast", "card", "object"] } },
+              "required": ["asset_type"]
+            },
+            "then": {
+              "not": { "anyOf": [
+                { "required": ["max_chars"] },
+                { "required": ["max_size_kb"] }
+              ] }
+            }
+          }
+        ]
+      }
+    },
+    "production_window_business_days": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "Typical production turnaround in business days when the format requires seller-side production (e.g., host-recording from a buyer-supplied script). 0 for synchronous (e.g., generative AI); >0 for human-produced (e.g., podcast host-read). Absent when no production is required (buyer uploads complete creative)."
+    }
+  },
+  "additionalProperties": true,
+  "x-canonical-policy-required-params-not-enforced": "Canonical format schemas intentionally do NOT mark any of their parameter fields as `required` and use `additionalProperties: true`. The canonical is the loose contract — describing what parameters MAY narrow it. Products narrow the canonical with concrete values (and may also leave most parameters absent — buyers infer behavior from the canonical's prose description for any unspecified parameter). This is intentional, not an oversight: enforcing required params on the canonical would force every product to declare every parameter, which is the wrong direction (we want products to declare only the values that differ from sensible canonical defaults). Adopters writing strict validators should validate against the canonical's structural shape (what fields ARE valid) and apply business rules separately for product-level narrowing minima."
+}
diff --git a/static/schemas/source/formats/canonical/agent_placement.json b/static/schemas/source/formats/canonical/agent_placement.json
new file mode 100644
index 0000000000..ea00b63349
--- /dev/null
+++ b/static/schemas/source/formats/canonical/agent_placement.json
@@ -0,0 +1,57 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/agent_placement.json",
+  "title": "Canonical Format: Agent Placement (AI-surface sponsored placement)",
+  "description": "**3.2-track canonical.** The structural shape (algorithmic composition + brand-context input + optional offering/landing_page) is captured here so adopters can declare against it in 3.1 catalogs, but the **mention-level tracking contract is intentionally underspecified for 3.1**: no normative macro vocabulary, no postback shape, no cross-surface dedup model. Adopters claiming `agent_placement` in 3.1 ship private tracking integrations and SHOULD set `runtime_status: 'preview'` or `'declared_only'` on the declaration; buyer agents MUST treat agent_placement attribution as adapter-defined until the 3.2 tracking-macro spec lands. The canonical promotes to a normatively-buyer-callable surface in 3.2 (or later) once the tracking contract is specified.\n\nSponsored placement integrated into an AI-surface's response to a user. Buyer supplies a `BrandRef` (resolving brand.json for context), an optional `offering_ref` to focus the mention on a specific offering, and an optional `landing_page_url` the surface MAY attach as a citation. The surface (LLM, voice assistant, sponsored-search ranker) composes a natural-language mention, sponsored card, or audio snippet within its response to a user query. **Composition is algorithmic** — the agent chooses phrasing and presentation. Output asset_type varies by surface: `text` for chat UIs and sponsored search snippets; `audio` (synthesized) for voice assistants; `card` for structured AI-surface result cards. Tracking model: mention-level impression + attribution events; per-mention id keys back to brand and offering — but see the 3.2-track note above; the wire shape of these events is not yet specified. Distinct from `si_chat` (which is the user-converses-with-brand's-agent pattern — brand owns the conversational surface) and from `sponsored_placement` (retail-media catalog-driven). Parallels `sponsored_placement` structurally: both are surface-composed placements; agent_placement is for AI/agentic surfaces, sponsored_placement is for retail media.",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "experimental": {
+      "default": true,
+      "description": "Marked experimental at 3.1 GA: the canonical's tracking model (mention-level impression + attribution, postback shape, cross-surface dedup) is intentionally underspecified for 3.1. Adopters claiming `agent_placement` ship private tracking integrations; buyer agents MUST treat attribution as adapter-defined until the 3.2 tracking-macro spec lands. Promotion to non-experimental gated on the 3.2 tracking-contract spec."
+    },
+    "v1_translatable": {
+      "default": false,
+      "description": "Inherently new in v2 — AI-surface sponsored mentions weren't expressible as v1 named formats. SDKs MUST NOT emit `FORMAT_PROJECTION_FAILED` for products using this canonical; the v1-unreachability is structural."
+    },
+    "slots": {
+      "default": [
+        { "asset_group_id": "offering_ref", "asset_type": "text", "required": false },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "agent_placement has minimal buyer-shipped slots — the surface composes the rendered output from brand context (resolved via the manifest's top-level `brand` BrandRef) plus optional offering_ref and landing_page_url assets. None of these assets are rendered verbatim by the buyer; the agent chooses how to use them."
+    },
+    "output_modality": {
+      "type": "string",
+      "enum": ["text", "audio", "card"],
+      "description": "How the surface presents the mention. `text` = inline text (chat, search snippet). `audio` = TTS-synthesized voice. `card` = structured card with optional image + text."
+    },
+    "max_mention_length_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "For text output: maximum length of the surface-composed mention text."
+    },
+    "max_mention_duration_ms": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "For audio output: maximum duration of the spoken mention in milliseconds."
+    },
+    "supports_offering_reference": {
+      "type": "boolean",
+      "description": "Whether the product accepts an offering reference (specific product/service to promote within the mention) in addition to brand context."
+    },
+    "supports_landing_page_url": {
+      "type": "boolean",
+      "description": "Whether the surface attaches a landing page URL to the mention (citation, learn-more link)."
+    },
+    "tone_constraints": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "**Advisory only.** Buyer-declared brand-voice preferences the surface SHOULD honor (e.g., ['formal', 'no_superlatives']). LLM/agentic surfaces have no protocol-level mechanism to verify enforcement — adopters that need hard guarantees should rely on brand.json voice declarations and post-mention review rather than this field. Future revisions may tie this to a structured tone vocabulary; for now treat as free-text guidance."
+    },
+    "disclosure_required": {
+      "type": "boolean",
+      "description": "Whether the surface must include an explicit sponsorship disclosure label."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/audio_daast.json b/static/schemas/source/formats/canonical/audio_daast.json
new file mode 100644
index 0000000000..f008149932
--- /dev/null
+++ b/static/schemas/source/formats/canonical/audio_daast.json
@@ -0,0 +1,46 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/audio_daast.json",
+  "title": "Canonical Format: DAAST Audio",
+  "description": "DAAST-tag-delivered audio creative (audio analog of VAST). Slot: `daast_tag` (daast asset, URL or inline XML). Tracking model: DAAST events inherent to the spec — `impression`, `firstQuartile`, `midpoint`, `thirdQuartile`, `complete`, `start`, `pause`, `resume`, `mute`, `unmute`, `clickTracking`, `error`. Distinct from `audio_hosted` (direct file with external tracking).",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "slots": {
+      "default": [
+        { "asset_group_id": "daast_tag", "asset_type": "daast", "required": true },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "Default slots for audio_daast canonical. Buyer ships a DAAST tag (URL or inline XML, 1.0 or 1.1) plus an optional clickthrough URL. Tracking events are inherent to DAAST and don't require explicit slots."
+    },
+    "daast_version": {
+      "type": "string",
+      "enum": ["1.0", "1.1"]
+    },
+    "duration_ms_range": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 0 },
+      "minItems": 2,
+      "maxItems": 2,
+      "description": "[min, max] duration in milliseconds. **Precedence**: `duration_ms_exact` takes precedence when both ship. SDKs SHOULD lint a warning when both fields ship."
+    },
+    "duration_ms_exact": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "When set, duration must equal exactly this value. Takes precedence over `duration_ms_range` when both ship."
+    },
+    "linear_required": {
+      "type": "boolean"
+    },
+    "max_wrapper_depth": {
+      "type": "integer",
+      "minimum": 0
+    },
+    "ssl_required": {
+      "type": "boolean"
+    },
+    "companion_image_required": {
+      "type": "boolean"
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/audio_hosted.json b/static/schemas/source/formats/canonical/audio_hosted.json
new file mode 100644
index 0000000000..7096d3cb8f
--- /dev/null
+++ b/static/schemas/source/formats/canonical/audio_hosted.json
@@ -0,0 +1,81 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/audio_hosted.json",
+  "title": "Canonical Format: Hosted Audio",
+  "description": "Direct audio creative — buyer ships an `audio` asset (mp3/aac/wav) for asset-driven products, or ships a `script` / `creative_brief` text asset for products where the seller produces audio internally (podcast host-reads, TTS synthesis). Optional companion slots: `companion_image`, `brand_name`, `landing_page_url`. Tracking model: standard impression + completion + companion-image-click pixels via universal_macros. Distinct from `audio_daast` (DAAST tag, inherent DAAST event tracking). For host-reads and synthesized audio, the format declares `asset_source: 'publisher_host_recorded'` or `'agent_synthesized'` plus `buyer_asset_acceptance: 'rejected'`; the format's `slots` declaration enumerates which assets the buyer ships (e.g., `script` text asset for host-reads). The seller decides how to consume each asset (render verbatim vs produce audio from text) — there is no separate manifest 'inputs' map; everything the buyer ships goes in `assets`.",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "slots": {
+      "default": [
+        { "asset_group_id": "audio_main", "asset_type": "audio", "required": true },
+        { "asset_group_id": "companion_image", "asset_type": "image", "required": false },
+        { "asset_group_id": "brand_name", "asset_type": "text", "required": false },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "Default slots for buyer-uploaded audio. Host-read products override with a `script` (asset_type: text) or `creative_brief` (asset_type: brief) slot in place of `audio_main`, plus `asset_source: 'publisher_host_recorded'` and `buyer_asset_acceptance: 'rejected'`. TTS-from-script products override similarly with `asset_source: 'seller_pre_rendered_from_brief'`."
+    },
+    "duration_ms_range": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 0 },
+      "minItems": 2,
+      "maxItems": 2,
+      "description": "[min, max] duration in milliseconds. **Precedence**: `duration_ms_exact` takes precedence when both ship on the same product. SDKs SHOULD lint a warning when both fields ship."
+    },
+    "duration_ms_exact": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "When set, duration must equal exactly this value. Takes precedence over `duration_ms_range` when both ship."
+    },
+    "audio_codecs": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["mp3", "aac", "wav", "opus", "flac"] }
+    },
+    "audio_sample_rates": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 1 }
+    },
+    "audio_channels": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["mono", "stereo"] }
+    },
+    "min_bitrate_kbps": { "type": "integer", "minimum": 1 },
+    "max_bitrate_kbps": { "type": "integer", "minimum": 1 },
+    "loudness_lufs": {
+      "type": "number",
+      "description": "Required integrated loudness in LUFS (typical: -16 for streaming/podcast, -23 for broadcast). Negative values."
+    },
+    "loudness_tolerance_db": {
+      "type": "number",
+      "minimum": 0,
+      "description": "Permitted deviation from loudness_lufs in dB."
+    },
+    "true_peak_dbfs": {
+      "type": "number",
+      "description": "Maximum true-peak level in dBFS (typical: -2)."
+    },
+    "asset_source": {
+      "type": "string",
+      "enum": ["buyer_uploaded", "publisher_host_recorded", "seller_pre_rendered_from_brief", "seller_human_designed", "agent_synthesized"],
+      "default": "buyer_uploaded",
+      "description": "Where the rendered audio bytes come from. Single shared enum across canonicals (see `image.json#asset_source` for the full semantics). `publisher_host_recorded`: the publisher's host records the audio (podcast host-read pattern); buyer must use the publisher's build_creative capability. This value is audio-specific."
+    },
+    "buyer_asset_acceptance": {
+      "type": "string",
+      "enum": ["accepted", "rejected"],
+      "default": "accepted",
+      "description": "Whether the product accepts buyer-uploaded audio. When `rejected`, the buyer cannot ship an audio asset directly — they must use build_creative (or sync_creatives with brief inputs) so the seller produces the audio. Combined with `asset_source`, lets a product declare 'I produce audio from briefs and refuse buyer uploads' (asset_source=`seller_pre_rendered_from_brief`, buyer_asset_acceptance=`rejected`)."
+    },
+    "companion_image_required": {
+      "type": "boolean"
+    },
+    "companion_image_aspect_ratio": {
+      "type": "string"
+    },
+    "companion_image_max_file_size_kb": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "brand_name_max_chars": { "type": "integer", "minimum": 1 }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/display_tag.json b/static/schemas/source/formats/canonical/display_tag.json
new file mode 100644
index 0000000000..70b0a66c02
--- /dev/null
+++ b/static/schemas/source/formats/canonical/display_tag.json
@@ -0,0 +1,288 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/display_tag.json",
+  "title": "Canonical Format: Display Tag",
+  "description": "Third-party-served display tag (JS, iframe, or 1\u00d71 redirect). The buyer's adserver hosts the creative; the seller calls the tag URL at impression time. Slot: `tag_url` (url asset with appropriate `url_type`). Tracking model: opaque to seller \u2014 third party serves and measures. Click tracking via redirect URL substitution using universal_macros. Distinct from `image` (static asset hosted by seller) and `html5` (zip bundle hosted by seller).",
+  "allOf": [
+    {
+      "$ref": "/schemas/formats/canonical/_base.json"
+    },
+    {
+      "title": "Size-mode mutex",
+      "description": "Exactly one of: (a) fixed (`width` + `height` both set), (b) multi-size (`sizes` set), (c) responsive (any of `min_width`/`max_width`/`min_height`/`max_height` set), (d) none (no size constraint declared \u2014 accepts any dimensions). Combining modes is rejected at schema layer.",
+      "oneOf": [
+        {
+          "title": "fixed",
+          "required": [
+            "width",
+            "height"
+          ],
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "sizes"
+                ]
+              },
+              {
+                "required": [
+                  "min_width"
+                ]
+              },
+              {
+                "required": [
+                  "max_width"
+                ]
+              },
+              {
+                "required": [
+                  "min_height"
+                ]
+              },
+              {
+                "required": [
+                  "max_height"
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "title": "multi-size",
+          "required": [
+            "sizes"
+          ],
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "width"
+                ]
+              },
+              {
+                "required": [
+                  "height"
+                ]
+              },
+              {
+                "required": [
+                  "min_width"
+                ]
+              },
+              {
+                "required": [
+                  "max_width"
+                ]
+              },
+              {
+                "required": [
+                  "min_height"
+                ]
+              },
+              {
+                "required": [
+                  "max_height"
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "title": "responsive",
+          "anyOf": [
+            {
+              "required": [
+                "min_width"
+              ]
+            },
+            {
+              "required": [
+                "max_width"
+              ]
+            },
+            {
+              "required": [
+                "min_height"
+              ]
+            },
+            {
+              "required": [
+                "max_height"
+              ]
+            }
+          ],
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "width"
+                ]
+              },
+              {
+                "required": [
+                  "height"
+                ]
+              },
+              {
+                "required": [
+                  "sizes"
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "title": "none",
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "width"
+                ]
+              },
+              {
+                "required": [
+                  "height"
+                ]
+              },
+              {
+                "required": [
+                  "sizes"
+                ]
+              },
+              {
+                "required": [
+                  "min_width"
+                ]
+              },
+              {
+                "required": [
+                  "max_width"
+                ]
+              },
+              {
+                "required": [
+                  "min_height"
+                ]
+              },
+              {
+                "required": [
+                  "max_height"
+                ]
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ],
+  "properties": {
+    "slots": {
+      "default": [
+        {
+          "asset_group_id": "tag_url",
+          "asset_type": "url",
+          "required": true
+        },
+        {
+          "asset_group_id": "backup_image",
+          "asset_type": "image",
+          "required": false
+        }
+      ],
+      "description": "Default slots for display_tag canonical. Buyer ships a URL pointing at the third-party-served creative (JS, iframe, or 1\u00d71 redirect) plus an optional backup image. Click and impression macros are substituted into the tag URL by the seller using `universal_macros`."
+    },
+    "width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Required tag rendering width in pixels \u2014 use for fixed-size slots. For multi-size flexible slots use `sizes[]`; for responsive use `min_width`/`max_width`/`min_height`/`max_height`. Exactly one of `(width, height)`, `sizes[]`, or `min/max_width` + `min/max_height` ranges MUST be set."
+    },
+    "height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Required tag rendering height in pixels. See `width` for size-mode mutual exclusion."
+    },
+    "sizes": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": [
+          "width",
+          "height"
+        ],
+        "properties": {
+          "width": {
+            "type": "integer",
+            "minimum": 1
+          },
+          "height": {
+            "type": "integer",
+            "minimum": 1
+          }
+        },
+        "additionalProperties": false
+      },
+      "description": "List of accepted (width, height) pairs for a multi-size flexible slot. The buyer's third-party tag must render at one of the listed sizes; the seller picks which size to request at impression time. Mutually exclusive with `(width, height)` and with responsive ranges."
+    },
+    "min_width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum accepted width for responsive third-party tags. Pair with `max_width`. Mutually exclusive with `(width, height)` and `sizes[]`."
+    },
+    "max_width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum accepted width for responsive third-party tags. Pair with `min_width`."
+    },
+    "min_height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum accepted height for responsive third-party tags. Pair with `max_height`."
+    },
+    "max_height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum accepted height for responsive third-party tags. Pair with `min_height`."
+    },
+    "supported_tag_types": {
+      "type": "array",
+      "items": {
+        "type": "string",
+        "enum": [
+          "iframe",
+          "javascript",
+          "1x1_redirect"
+        ]
+      },
+      "description": "Tag delivery mechanisms accepted."
+    },
+    "ssl_required": {
+      "type": "boolean",
+      "description": "Whether the tag URL must be HTTPS."
+    },
+    "max_redirect_depth": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "Maximum redirect chain depth permitted."
+    },
+    "max_response_time_ms": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum tag-server response time in milliseconds."
+    },
+    "backup_image_required": {
+      "type": "boolean",
+      "description": "Whether a backup image must accompany the tag for environments that cannot render the third-party tag."
+    },
+    "backup_image_max_size_kb": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "om_sdk_required": {
+      "type": "boolean",
+      "description": "Whether the buyer's tag must integrate IAB Open Measurement SDK for viewability."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/html5.json b/static/schemas/source/formats/canonical/html5.json
new file mode 100644
index 0000000000..a3349e4b85
--- /dev/null
+++ b/static/schemas/source/formats/canonical/html5.json
@@ -0,0 +1,316 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/html5.json",
+  "title": "Canonical Format: HTML5 Banner",
+  "description": "Interactive HTML5 banner delivered as a zip archive. Slot: `html5_bundle` (zip asset). Tracking model: MRAID + IAB Open Measurement (OM-SDK) + click-tag macro substitution + backup image fallback. Receivers unpack the zip, validate internal structure, and serve from CDN. Distinct from `image` (static, non-interactive) and `display_tag` (third-party served). The zip's entry point is typically `index.html`; click handling uses `clickTag` (or `clickTAG`) macro substitution.",
+  "allOf": [
+    {
+      "$ref": "/schemas/formats/canonical/_base.json"
+    },
+    {
+      "title": "Size-mode mutex",
+      "description": "Exactly one of: (a) fixed (`width` + `height` both set), (b) multi-size (`sizes` set), (c) responsive (any of `min_width`/`max_width`/`min_height`/`max_height` set), (d) none (no size constraint declared \u2014 accepts any dimensions). Combining modes is rejected at schema layer.",
+      "oneOf": [
+        {
+          "title": "fixed",
+          "required": [
+            "width",
+            "height"
+          ],
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "sizes"
+                ]
+              },
+              {
+                "required": [
+                  "min_width"
+                ]
+              },
+              {
+                "required": [
+                  "max_width"
+                ]
+              },
+              {
+                "required": [
+                  "min_height"
+                ]
+              },
+              {
+                "required": [
+                  "max_height"
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "title": "multi-size",
+          "required": [
+            "sizes"
+          ],
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "width"
+                ]
+              },
+              {
+                "required": [
+                  "height"
+                ]
+              },
+              {
+                "required": [
+                  "min_width"
+                ]
+              },
+              {
+                "required": [
+                  "max_width"
+                ]
+              },
+              {
+                "required": [
+                  "min_height"
+                ]
+              },
+              {
+                "required": [
+                  "max_height"
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "title": "responsive",
+          "anyOf": [
+            {
+              "required": [
+                "min_width"
+              ]
+            },
+            {
+              "required": [
+                "max_width"
+              ]
+            },
+            {
+              "required": [
+                "min_height"
+              ]
+            },
+            {
+              "required": [
+                "max_height"
+              ]
+            }
+          ],
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "width"
+                ]
+              },
+              {
+                "required": [
+                  "height"
+                ]
+              },
+              {
+                "required": [
+                  "sizes"
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "title": "none",
+          "not": {
+            "anyOf": [
+              {
+                "required": [
+                  "width"
+                ]
+              },
+              {
+                "required": [
+                  "height"
+                ]
+              },
+              {
+                "required": [
+                  "sizes"
+                ]
+              },
+              {
+                "required": [
+                  "min_width"
+                ]
+              },
+              {
+                "required": [
+                  "max_width"
+                ]
+              },
+              {
+                "required": [
+                  "min_height"
+                ]
+              },
+              {
+                "required": [
+                  "max_height"
+                ]
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ],
+  "properties": {
+    "slots": {
+      "default": [
+        {
+          "asset_group_id": "html5_bundle",
+          "asset_type": "zip",
+          "required": true
+        },
+        {
+          "asset_group_id": "backup_image",
+          "asset_type": "image",
+          "required": false
+        },
+        {
+          "asset_group_id": "landing_page_url",
+          "asset_type": "url",
+          "required": false
+        }
+      ],
+      "description": "Default slots for html5 canonical. Buyer ships a zip bundle plus optional backup image (required when `backup_image_required: true`) and clickthrough URL. The zip's entry point is typically `index.html`; click handling uses the `clickTag` (or `clickTAG`) macro substituted by the seller at serve time."
+    },
+    "width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Required banner width in pixels \u2014 use for fixed-size slots. For multi-size flexible slots use `sizes[]`; for responsive use `min_width`/`max_width`/`min_height`/`max_height`. Exactly one of `(width, height)`, `sizes[]`, or `min/max_width` + `min/max_height` ranges MUST be set."
+    },
+    "height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Required banner height in pixels. See `width` for size-mode mutual exclusion."
+    },
+    "sizes": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": [
+          "width",
+          "height"
+        ],
+        "properties": {
+          "width": {
+            "type": "integer",
+            "minimum": 1
+          },
+          "height": {
+            "type": "integer",
+            "minimum": 1
+          }
+        },
+        "additionalProperties": false
+      },
+      "description": "List of accepted (width, height) pairs for a multi-size flexible slot (publisher banner that accepts 300\u00d7250 OR 728\u00d790 OR 970\u00d7250). Mirrors OpenRTB `banner.format[]`. Mutually exclusive with `(width, height)` and with responsive ranges."
+    },
+    "min_width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum accepted width for responsive HTML5 banners that adapt within a range. Pair with `max_width`. Mutually exclusive with `(width, height)` and `sizes[]`."
+    },
+    "max_width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum accepted width for responsive HTML5 banners. Pair with `min_width`."
+    },
+    "min_height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum accepted height for responsive HTML5 banners. Pair with `max_height`."
+    },
+    "max_height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum accepted height for responsive HTML5 banners. Pair with `min_height`."
+    },
+    "max_initial_load_kb": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum initial-load file size (zip + above-the-fold assets) in kilobytes. IAB display standards: 200 KB for fixed sizes, 100 KB for mobile."
+    },
+    "max_polite_load_kb": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum polite-load file size after host-initiated subload, in kilobytes. IAB display standards: 500 KB for fixed sizes."
+    },
+    "host_initiated_subload": {
+      "type": "boolean",
+      "description": "Whether the host page must initiate the polite-load phase. IAB-compliant banners require true."
+    },
+    "max_animation_duration_ms": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "Maximum total animation duration in milliseconds. IAB standard: 30000 (30 seconds)."
+    },
+    "max_cpu_load_percent": {
+      "type": "integer",
+      "minimum": 1,
+      "maximum": 100,
+      "description": "Maximum CPU load percentage during render."
+    },
+    "mraid_required": {
+      "type": "boolean",
+      "description": "Whether MRAID compatibility is required (mobile in-app)."
+    },
+    "mraid_version": {
+      "type": "string",
+      "enum": [
+        "2.0",
+        "3.0"
+      ],
+      "description": "Required MRAID version when mraid_required is true."
+    },
+    "om_sdk_required": {
+      "type": "boolean",
+      "description": "Whether IAB Open Measurement SDK integration is required."
+    },
+    "clicktag_macro": {
+      "type": "string",
+      "enum": [
+        "clickTag",
+        "clickTAG"
+      ],
+      "description": "Name of the click-tag macro the bundle must use."
+    },
+    "backup_image_required": {
+      "type": "boolean",
+      "description": "Whether a backup image must accompany the zip for non-HTML5 environments."
+    },
+    "backup_image_max_size_kb": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum backup image file size in kilobytes."
+    },
+    "ssl_required": {
+      "type": "boolean"
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/image.json b/static/schemas/source/formats/canonical/image.json
new file mode 100644
index 0000000000..c6ab64e66b
--- /dev/null
+++ b/static/schemas/source/formats/canonical/image.json
@@ -0,0 +1,174 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/image.json",
+  "title": "Canonical Format: Image",
+  "description": "Static image creative format. Slots: `image_main` (image asset, file or hosted URL), optional `headline` (text), `body_text` (text), `cta` (text/enum), `landing_page_url` (url). Tracking model: impression pixel + click URL via universal_macros, with optional viewability pixel. Distinct from `html5` (interactive bundles) and `display_tag` (third-party served). AR/dimensions narrow to specific sizes via product parameters — covers IAB display sizes (300x250, 728x90, 970x250, etc.) without a separate iab_size enum.",
+  "allOf": [
+    { "$ref": "/schemas/formats/canonical/_base.json" },
+    {
+      "title": "Size-mode mutex",
+      "description": "Exactly one of: (a) fixed (`width` + `height` both set), (b) multi-size (`sizes` set), (c) responsive (any of `min_width`/`max_width`/`min_height`/`max_height` set), (d) none (no size constraint declared — accepts any dimensions). Combining modes (e.g., `width` + `sizes`) is rejected at schema layer; same rule on `html5` and `display_tag` canonicals.",
+      "oneOf": [
+        {
+          "title": "fixed",
+          "required": ["width", "height"],
+          "not": {
+            "anyOf": [
+              { "required": ["sizes"] },
+              { "required": ["min_width"] },
+              { "required": ["max_width"] },
+              { "required": ["min_height"] },
+              { "required": ["max_height"] }
+            ]
+          }
+        },
+        {
+          "title": "multi-size",
+          "required": ["sizes"],
+          "not": {
+            "anyOf": [
+              { "required": ["width"] },
+              { "required": ["height"] },
+              { "required": ["min_width"] },
+              { "required": ["max_width"] },
+              { "required": ["min_height"] },
+              { "required": ["max_height"] }
+            ]
+          }
+        },
+        {
+          "title": "responsive",
+          "anyOf": [
+            { "required": ["min_width"] },
+            { "required": ["max_width"] },
+            { "required": ["min_height"] },
+            { "required": ["max_height"] }
+          ],
+          "not": {
+            "anyOf": [
+              { "required": ["width"] },
+              { "required": ["height"] },
+              { "required": ["sizes"] }
+            ]
+          }
+        },
+        {
+          "title": "none",
+          "not": {
+            "anyOf": [
+              { "required": ["width"] },
+              { "required": ["height"] },
+              { "required": ["sizes"] },
+              { "required": ["min_width"] },
+              { "required": ["max_width"] },
+              { "required": ["min_height"] },
+              { "required": ["max_height"] }
+            ]
+          }
+        }
+      ]
+    }
+  ],
+  "properties": {
+    "slots": {
+      "default": [
+        { "asset_group_id": "image_main", "asset_type": "image", "required": true },
+        { "asset_group_id": "headline", "asset_type": "text", "required": false },
+        { "asset_group_id": "body_text", "asset_type": "text", "required": false },
+        { "asset_group_id": "primary_text", "asset_type": "text", "required": false },
+        { "asset_group_id": "cta", "asset_type": "text", "required": false },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "Default slots for image canonical. Buyer ships an image asset (file or hosted URL) plus optional headline, body text, primary text (long-form caption), CTA (typically constrained to an enum via `cta_values`), and clickthrough URL. Products MAY override the default — make `headline` required, narrow `cta` to a value enum, or remove slots the surface doesn't consume."
+    },
+    "width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Required image width in pixels — use for fixed-size slots (e.g., a 300×250 IAB MREC). For multi-size flexible slots (publisher MREC slot that accepts 300×250 OR 728×90 OR 970×250), use `sizes[]` instead; for responsive slots that adapt to viewport, use `min_width`/`max_width`/`min_height`/`max_height`. The three modes are mutually exclusive — set exactly one of `(width+height)`, `sizes[]`, or `min/max_width` + `min/max_height` ranges."
+    },
+    "height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Required image height in pixels. See `width` for size-mode mutual exclusion."
+    },
+    "sizes": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": ["width", "height"],
+        "properties": {
+          "width": { "type": "integer", "minimum": 1 },
+          "height": { "type": "integer", "minimum": 1 }
+        },
+        "additionalProperties": false
+      },
+      "description": "List of accepted (width, height) pairs for a multi-size flexible slot. Buyer ships an asset matching one of the listed sizes; SDK validates `assets.image_main.{width,height}` against the list (any-match). Mirrors OpenRTB `banner.format[]` semantics — one declaration with N accepted sizes is cleaner than N format_options entries. Mutually exclusive with `(width, height)` and with `min/max_width` + `min/max_height` ranges."
+    },
+    "min_width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum accepted width in pixels for responsive slots that adapt within a range (e.g., 'any width from 300 to 970'). Use with `max_width` (and optionally `min_height`/`max_height`). Mutually exclusive with `(width, height)` and `sizes[]`."
+    },
+    "max_width": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum accepted width in pixels for responsive slots. Pair with `min_width`. See `min_width` for size-mode mutual exclusion."
+    },
+    "min_height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum accepted height in pixels for responsive slots. Pair with `max_height`."
+    },
+    "max_height": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum accepted height in pixels for responsive slots. Pair with `min_height`."
+    },
+    "aspect_ratio": {
+      "type": "string",
+      "pattern": "^[0-9]+(\\.[0-9]+)?:[0-9]+(\\.[0-9]+)?$",
+      "description": "Optional aspect ratio constraint (e.g., '1.91:1', '1:1'). When provided alongside `width`/`height`, must agree. When used with `sizes[]` or responsive ranges, narrows accepted entries to those matching the aspect ratio."
+    },
+    "max_file_size_kb": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum file size in kilobytes."
+    },
+    "image_formats": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["jpg", "jpeg", "png", "gif", "webp", "svg"] },
+      "description": "Permitted image file formats."
+    },
+    "ssl_required": {
+      "type": "boolean",
+      "description": "Whether the image and its trackers must be served over HTTPS."
+    },
+    "headline_max_chars": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "body_text_max_chars": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "cta_values": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "Permitted CTA values for this product (e.g., ['LEARN_MORE', 'SHOP_NOW'])."
+    },
+    "asset_source": {
+      "type": "string",
+      "enum": ["buyer_uploaded", "publisher_host_recorded", "seller_pre_rendered_from_brief", "seller_human_designed", "agent_synthesized"],
+      "default": "buyer_uploaded",
+      "description": "Where the rendered asset bytes come from. Single shared enum across all canonicals (`image`, `video_hosted`, `audio_hosted` — replaces the earlier per-canonical `image_source` / `video_source` / `audio_source` fields). `buyer_uploaded` (default): buyer ships a pre-rendered asset. `publisher_host_recorded`: publisher's host records the asset (audio-specific; podcast host-read pattern). `seller_pre_rendered_from_brief`: buyer ships a brief plus structured copy; seller renders ONE asset at sync_creatives or build_creative time (generative-DSP pattern). `seller_human_designed`: seller's design team renders manually from a brief. `agent_synthesized`: AI synthesis pipeline; pair with `synthesis_nondeterministic: true` when the platform cannot guarantee in-spec output (Veo/Sora/Imagen-class).\n\nNot every value is meaningful on every canonical — `publisher_host_recorded` is audio-specific; on `image` or `video_hosted` it has no defined behavior. Adopters MUST select a value appropriate to the canonical's asset type. The `slots` declaration is the binding contract for what the buyer ships; `asset_source` is informational and lets buyers understand the production model when picking products."
+    },
+    "buyer_asset_acceptance": {
+      "type": "string",
+      "enum": ["accepted", "rejected"],
+      "default": "accepted",
+      "description": "Whether the product accepts buyer-uploaded assets. When `rejected`, the buyer cannot ship pre-rendered bytes directly — they must use build_creative (or sync_creatives with brief inputs) so the seller produces the asset. Combined with `asset_source`, lets a product declare 'I produce assets from briefs and refuse buyer uploads' (asset_source=`seller_pre_rendered_from_brief`, buyer_asset_acceptance=`rejected`)."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/image_carousel.json b/static/schemas/source/formats/canonical/image_carousel.json
new file mode 100644
index 0000000000..5c8dcd74dd
--- /dev/null
+++ b/static/schemas/source/formats/canonical/image_carousel.json
@@ -0,0 +1,75 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/image_carousel.json",
+  "title": "Canonical Format: Image Carousel",
+  "description": "Multi-card swipeable carousel. The buyer ships a `cards` slot whose value is an **array** of [card-asset](/schemas/core/assets/card-asset.json) objects (a single key with an array value — NOT one key per card, NOT dotted/bracketed paths). Each card-asset carries: `asset_type: \"card\"`, `media` (an image or video asset), optional `headline` (text), optional `landing_page_url` (url asset). Per-card structure is the same across all cards; mixed orientations not allowed within a single carousel. Tracking model: per-card impression and engagement pixels + carousel-level engagement (swipe, view-time). Allowed asset types for a card's `media` field: `image` and `video` (Meta-style mixed-media); platforms can narrow to image-only or video-only via `allowed_card_media_asset_types`.\n\nThe manifest's `assets.cards` value is an array of card-asset objects. Example: `\"cards\": [{\"asset_type\": \"card\", \"media\": {\"asset_type\": \"image\", \"url\": \"...\"}, \"headline\": \"Buy now\", \"landing_page_url\": {\"asset_type\": \"url\", \"url_type\": \"clickthrough\", \"url\": \"...\"}}, ...]`. Each card-asset validates against the card schema; per-card platform extensions attach via the card's `platform_extensions` field, never via inline non-canonical keys.",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "v1_translatable": {
+      "default": false,
+      "description": "Inherently new in v2 — multi-card carousels (Meta carousel, Pinterest pin collections, Snap collection ads) weren't expressible as v1 named formats. SDKs MUST NOT emit `FORMAT_PROJECTION_FAILED` for products using this canonical; the v1-unreachability is structural."
+    },
+    "slots": {
+      "default": [
+        { "asset_group_id": "cards", "asset_type": "card", "required": true, "min": 2, "max": 10 },
+        { "asset_group_id": "primary_text", "asset_type": "text", "required": false },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "Default slots for image_carousel. The `cards` slot's value in the manifest is an array of [card-asset](/schemas/core/assets/card-asset.json) objects; `min` / `max` constrain card count."
+    },
+    "card_aspect_ratio": {
+      "type": "string",
+      "pattern": "^[0-9]+(\\.[0-9]+)?:[0-9]+(\\.[0-9]+)?$",
+      "description": "Aspect ratio shared across all cards (e.g., '1:1', '1.91:1', '4:5')."
+    },
+    "min_cards": {
+      "type": "integer",
+      "minimum": 2,
+      "description": "Minimum card count (typical: 2 or 3)."
+    },
+    "max_cards": {
+      "type": "integer",
+      "description": "Maximum card count (typical: 6, 10, or 35 depending on platform)."
+    },
+    "allowed_card_media_asset_types": {
+      "type": "array",
+      "items": {
+        "type": "string",
+        "enum": ["image", "video"]
+      },
+      "description": "Asset types each card's `media` field may carry. Default: ['image']. Polymorphic carousels (Meta) allow ['image', 'video']. Renamed from `allowed_card_asset_types` to disambiguate that this constrains the card's media payload, not the card-asset itself (which is always asset_type: \"card\")."
+    },
+    "allowed_card_asset_types": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["image", "video"] },
+      "description": "DEPRECATED — alias for `allowed_card_media_asset_types`. Kept for back-compat; prefer the new field name. Removed in 5.0."
+    },
+    "card_image_max_file_size_kb": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "card_video_max_duration_ms": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "primary_text_max_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum length of the carousel-level primary text."
+    },
+    "card_headline_max_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Per-card headline character limit. Governs the `headline` field on each card-asset in the `cards` slot."
+    },
+    "card_description_max_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Per-card description character limit. Governs the `description` field on each card-asset in the `cards` slot. Distinct from `card_headline_max_chars`: description is longer body copy (typically 100-500 chars); headline is the short label (typically 25-40 chars)."
+    },
+    "ssl_required": {
+      "type": "boolean"
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/native_in_feed.json b/static/schemas/source/formats/canonical/native_in_feed.json
new file mode 100644
index 0000000000..dd628e9840
--- /dev/null
+++ b/static/schemas/source/formats/canonical/native_in_feed.json
@@ -0,0 +1,107 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/native_in_feed.json",
+  "title": "Canonical Format: Native In-Feed",
+  "description": "IAB-shaped native creative for in-feed and content-recommendation surfaces. Default slots cover the primary IAB OpenRTB Native 1.2 asset types — `title` (Title Asset), `body_text` (Data Asset type 2), `main_image` (Image Asset main), `icon` (Image Asset icon), `cta` (Data Asset type 12), `advertiser_name` (Data Asset type 1), `sponsored_label` (Title-adjacent), `landing_page_url` (Link Asset), `display_url` (Data Asset type 11 — visible URL/domain, distinct from clickthrough), `rating` (Data Asset type 3 — app/product rating), `price` (Data Asset type 6 — product price), plus renderer-fired `impression_tracker` / `viewability_tracker` / `click_tracker` (`pixel_tracker`). Products MAY use `slots_override` to add other IAB Native data asset types (likes — type 4, downloads — type 5, saleprice — type 7, phone_number — type 8, address — type 9, desc2 — type 10, etc.) or to remove slots the surface doesn't render. The publisher's renderer assembles these into its own look-and-feel — feed card, content-recommendation slot, in-stream native unit. Buyer ships a single asset bundle; the surface chooses presentation.\n\n**Scope (normative — buyer-agent routing).** This canonical is the home for:\n- IAB OpenRTB Native 1.2 in-feed native ads (publisher feeds, app feeds)\n- Content-recommendation widgets (Taboola, Outbrain, Yahoo Recommendations)\n- AdMob Native / Yahoo Native publisher slots\n- In-feed sponsored placements without catalog dependency\n\n**Not this canonical:**\n- Catalog-driven retail-media (Amazon SP, Criteo SP, CitrusAd SP) — use `sponsored_placement` (requires `source_catalog`).\n- Algorithmic surface that picks from a buyer-supplied asset pool (Google PMax, Meta Advantage+) — use `responsive_creative`.\n- Multi-card carousel — use `image_carousel`.\n- Video-first native units where the asset is a hosted video file — use `video_hosted` with `applies_to_channels: [\"native\"]`.\n\nDistinct from `sponsored_placement` along the catalog axis: native_in_feed is asset-bundle composition; sponsored_placement is catalog-row composition. A buyer agent reading `format_kind: native_in_feed` knows to assemble title + image + body + CTA; reading `format_kind: sponsored_placement` knows to attach a catalog feed.",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "experimental": {
+      "default": false,
+      "description": "Stable at 3.1 GA. Shape mirrors IAB OpenRTB Native 1.2 — the renderer contract is well-established across in-feed native and content-recommendation adopters."
+    },
+    "v1_translatable": {
+      "default": true,
+      "description": "Translates to v1 named native formats (e.g., `native_standard`, `native_content`) via the projection registry. Sellers with existing v1 named native formats SHOULD point `v1_format_ref[]` at them."
+    },
+    "slots": {
+      "default": [
+        { "asset_group_id": "title", "asset_type": "text", "required": true },
+        { "asset_group_id": "body_text", "asset_type": "text", "required": false },
+        { "asset_group_id": "main_image", "asset_type": "image", "required": false },
+        { "asset_group_id": "icon", "asset_type": "image", "required": false },
+        { "asset_group_id": "cta", "asset_type": "text", "required": false },
+        { "asset_group_id": "advertiser_name", "asset_type": "text", "required": true },
+        { "asset_group_id": "sponsored_label", "asset_type": "text", "required": false },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": true },
+        { "asset_group_id": "display_url", "asset_type": "text", "required": false },
+        { "asset_group_id": "rating", "asset_type": "text", "required": false },
+        { "asset_group_id": "price", "asset_type": "text", "required": false },
+        { "asset_group_id": "impression_tracker", "asset_type": "pixel_tracker", "required": false },
+        { "asset_group_id": "viewability_tracker", "asset_type": "pixel_tracker", "required": false },
+        { "asset_group_id": "click_tracker", "asset_type": "pixel_tracker", "required": false }
+      ],
+      "description": "Default slot shape for native_in_feed. Mirrors IAB OpenRTB Native 1.2 asset types. Products MAY override (`slots_override` on the projection ref) to narrow per-slot limits (`max_chars` on title/body) or remove unused slots (a content-recommendation slot that doesn't display an icon)."
+    },
+    "title_max_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum character length for the title slot. IAB native typical: 25 (short) to 90 (long). Buyer agents SHOULD validate ship-time title length against this."
+    },
+    "body_text_max_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum character length for the body_text slot. IAB native typical: 90 (mainline) to 140 (extended)."
+    },
+    "cta_max_chars": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum character length for the cta slot. Typical: 15–25."
+    },
+    "cta_values": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "Permitted CTA values for this product (e.g., ['LEARN_MORE', 'SHOP_NOW', 'SIGN_UP', 'DOWNLOAD']). When set, narrows the cta slot to a closed enum."
+    },
+    "main_image_sizes": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": ["width", "height"],
+        "properties": {
+          "width": { "type": "integer", "minimum": 1 },
+          "height": { "type": "integer", "minimum": 1 }
+        },
+        "additionalProperties": false
+      },
+      "description": "Accepted (width, height) pairs for the main_image slot. Common IAB native sizes: 1200×627 (1.91:1), 1080×1080 (1:1), 1080×1350 (4:5)."
+    },
+    "icon_size": {
+      "type": "object",
+      "required": ["width", "height"],
+      "properties": {
+        "width": { "type": "integer", "minimum": 1 },
+        "height": { "type": "integer", "minimum": 1 }
+      },
+      "additionalProperties": false,
+      "description": "Required (width, height) for the icon slot when present (typical: 80×80 or 100×100)."
+    },
+    "max_image_file_size_kb": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Maximum file size in kilobytes for main_image and icon."
+    },
+    "image_formats": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["jpg", "jpeg", "png", "gif", "webp"] },
+      "description": "Permitted image file formats."
+    },
+    "ssl_required": {
+      "type": "boolean",
+      "description": "Whether trackers, landing pages, and image URLs must be served over HTTPS."
+    },
+    "asset_source": {
+      "type": "string",
+      "enum": ["buyer_uploaded", "seller_pre_rendered_from_brief", "seller_human_designed", "agent_synthesized"],
+      "default": "buyer_uploaded",
+      "description": "Where the rendered native assets come from. `publisher_host_recorded` is omitted (audio-specific and not meaningful for native). Other values mirror the shared production-source axis used on `image` / `video_hosted`. `buyer_uploaded` (default): buyer ships pre-rendered title/image/body. `seller_pre_rendered_from_brief`: buyer ships a brief, seller renders the native bundle. `agent_synthesized`: AI synthesis pipeline produces title + image + body from a brief; pair with `synthesis_nondeterministic: true` for generative pipelines that can't guarantee in-spec output."
+    },
+    "buyer_asset_acceptance": {
+      "type": "string",
+      "enum": ["accepted", "rejected"],
+      "default": "accepted",
+      "description": "Whether the product accepts buyer-uploaded native assets. When `rejected`, the buyer cannot ship pre-rendered title/image/body — they must use `build_creative` (or `sync_creatives` with brief inputs) so the seller produces the native bundle from a brief."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/responsive_creative.json b/static/schemas/source/formats/canonical/responsive_creative.json
new file mode 100644
index 0000000000..52be7714fa
--- /dev/null
+++ b/static/schemas/source/formats/canonical/responsive_creative.json
@@ -0,0 +1,63 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/responsive_creative.json",
+  "title": "Canonical Format: Responsive Creative",
+  "description": "Buyer supplies a pool of typed assets (multiple headlines, descriptions, images, videos, logos); the surface algorithmically composes combinations per placement. **Composition is algorithmic** — surface picks combinations and reports per-asset performance breakdowns. Covers Google Responsive Display Ads (RDA), Responsive Search Ads (RSA), Performance Max (PMax), Demand Gen, and Meta Advantage+ creative. Industry term: \"Responsive\" (Google) / \"Advantage+ creative\" (Meta) / \"Dynamic Creative\" (older Meta term). Distinct from `sponsored_placement` (catalog-driven, deterministic) and `agent_placement` (AI-surface composition). The structured `slots` field below enumerates expected canonical asset_group_id slots; per-slot count/length narrowing lives in flat parameters (`headlines_min`, `headline_max_chars`, etc.).",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "experimental": {
+      "default": true,
+      "description": "Marked experimental at 3.1 GA: composition is algorithmic (the surface picks combinations and reports per-asset breakdowns), and there's no clean v1-translatable equivalent. Buyers ship asset pools rather than rendered creatives; the surface's per-impression composition cannot be predicted by `validate_input`. Adopters SHOULD validate behavior per surface (Google PMax vs Meta Advantage+ creative differ meaningfully)."
+    },
+    "v1_translatable": {
+      "default": false,
+      "description": "Inherently new in v2 — algorithmic asset-pool composition (Google PMax / Meta Advantage+ creative) wasn't expressible as v1 named formats. SDKs MUST NOT emit `FORMAT_PROJECTION_FAILED` for products using this canonical; the v1-unreachability is structural."
+    },
+    "slots": {
+      "default": [
+        { "asset_group_id": "headlines", "asset_type": "text", "required": true, "min": 3, "max": 15 },
+        { "asset_group_id": "long_headlines", "asset_type": "text", "required": false, "min": 1, "max": 5 },
+        { "asset_group_id": "descriptions", "asset_type": "text", "required": true, "min": 2, "max": 5 },
+        { "asset_group_id": "images_landscape", "asset_type": "image", "required": false, "min": 1, "max": 20 },
+        { "asset_group_id": "images_square", "asset_type": "image", "required": false, "min": 1, "max": 20 },
+        { "asset_group_id": "images_vertical", "asset_type": "image", "required": false, "min": 1, "max": 20 },
+        { "asset_group_id": "video", "asset_type": "video", "required": false, "min": 0, "max": 5 },
+        { "asset_group_id": "logo", "asset_type": "image", "required": true, "min": 1, "max": 5 },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": true, "min": 1, "max": 1 }
+      ]
+    },
+    "headlines_min": { "type": "integer", "minimum": 0 },
+    "headlines_max": { "type": "integer", "minimum": 0 },
+    "headline_max_chars": { "type": "integer", "minimum": 1 },
+    "long_headlines_min": { "type": "integer", "minimum": 0 },
+    "long_headlines_max": { "type": "integer", "minimum": 0 },
+    "long_headline_max_chars": { "type": "integer", "minimum": 1 },
+    "descriptions_min": { "type": "integer", "minimum": 0 },
+    "descriptions_max": { "type": "integer", "minimum": 0 },
+    "description_max_chars": { "type": "integer", "minimum": 1 },
+    "images_landscape_min": { "type": "integer", "minimum": 0 },
+    "images_landscape_max": { "type": "integer", "minimum": 0 },
+    "images_landscape_aspect_ratio": { "type": "string" },
+    "images_square_min": { "type": "integer", "minimum": 0 },
+    "images_square_max": { "type": "integer", "minimum": 0 },
+    "images_vertical_min": { "type": "integer", "minimum": 0 },
+    "images_vertical_max": { "type": "integer", "minimum": 0 },
+    "videos_min": { "type": "integer", "minimum": 0 },
+    "videos_max": { "type": "integer", "minimum": 0 },
+    "video_min_duration_ms": { "type": "integer", "minimum": 1 },
+    "video_max_duration_ms": { "type": "integer", "minimum": 1 },
+    "logo_min": { "type": "integer", "minimum": 0 },
+    "logo_max": { "type": "integer", "minimum": 0 },
+    "logo_aspect_ratios": {
+      "type": "array",
+      "items": { "type": "string" }
+    },
+    "business_name_max_chars": { "type": "integer", "minimum": 1 },
+    "asset_image_max_file_size_kb": { "type": "integer", "minimum": 1 },
+    "supports_catalog_input": {
+      "type": "boolean",
+      "description": "Whether the product can additionally consume a catalog reference (e.g., PMax with product feed)."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/sponsored_placement.json b/static/schemas/source/formats/canonical/sponsored_placement.json
new file mode 100644
index 0000000000..d72831bb00
--- /dev/null
+++ b/static/schemas/source/formats/canonical/sponsored_placement.json
@@ -0,0 +1,67 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/sponsored_placement.json",
+  "title": "Canonical Format: Sponsored Placement (retail-media catalog-driven)",
+  "description": "Catalog-driven retail-media format. Slot: `source_catalog` (catalog asset — product/SKU/ASIN/GTIN catalog reference, REQUIRED), optional `hero_asset`, optional `landing_page_url`. Buyer supplies the catalog reference; surface composes per-item or multi-item rendering using its native placement template. **Composition is deterministic** — buyer can predict per-slot rendering from the catalog item structure. Tracking model: per-item impression + click + conversion (catalog-keyed via offering_id/sku/gtin macros). Covers Amazon Sponsored Products, Criteo Sponsored Products, CitrusAd Sponsored Products, Walmart Connect Sponsored Products, Pinterest Collection (catalog-driven mode).\n\n**Scope (normative — buyer-agent routing).** This canonical is the home for catalog-driven retail-media placements ONLY. The defining feature is the `source_catalog` slot — products under this canonical compose their creative *per catalog item* using the buyer-supplied catalog feed. Without a catalog feed there is nothing to render against. Buyer agents reading `format_kind: sponsored_placement` MUST attach a catalog reference; sellers MUST require `source_catalog` in the manifest.\n\n**Not this canonical (route elsewhere):**\n- IAB in-feed native ads, content-recommendation widgets (Taboola, Outbrain, Yahoo Native, AdMob Native, in-feed sponsored cards) — use `native_in_feed` (asset-bundle composition; no catalog).\n- Algorithmic surface that picks from a buyer-supplied asset pool (Google PMax, Meta Advantage+) — use `responsive_creative`.\n- Single-image or single-video creative — use `image` or `video_hosted`.\n\nThe earlier broader framing ('any sponsored placement') was too loose for buyer-agent routing — a buyer reading `sponsored_placement` couldn't disambiguate a catalog-driven Amazon SP from an in-feed Taboola widget. As of 3.1, the canonical is narrowed to catalog-keyed retail-media; native moves to `native_in_feed`. Distinct from `responsive_creative` (algorithmic combinator from buyer pool) and `agent_placement` (text/audio AI-surface composition).",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "experimental": {
+      "default": true,
+      "description": "Marked experimental at 3.1 GA: the canonical covers 4 meaningfully different retail-media adapter contracts (Amazon SP, Criteo SP / CitrusAd SP, Pinterest Collection, generative-per-SKU). Adopter contracts vary; buyers MUST validate per-adapter behavior before routing budget. Promotion to non-experimental gated on the #4592 adapter-contract docs work."
+    },
+    "v1_translatable": {
+      "default": false,
+      "description": "Inherently new in v2 — retail-media catalog placements weren't expressible as v1 named formats. SDKs MUST NOT emit `FORMAT_PROJECTION_FAILED` for products using this canonical; the v1-unreachability is structural, not a registry-coverage gap."
+    },
+    "slots": {
+      "default": [
+        { "asset_group_id": "source_catalog", "required": true, "asset_type": "catalog" },
+        { "asset_group_id": "hero_asset", "required": false, "asset_type": "image" },
+        { "asset_group_id": "landing_page_url", "required": false, "asset_type": "url" }
+      ]
+    },
+    "supported_catalog_types": {
+      "type": "array",
+      "items": {
+        "type": "string",
+        "enum": ["product", "store", "offering", "hotel", "flight", "vehicle", "real_estate", "education", "destination", "app", "job", "inventory"]
+      },
+      "description": "Catalog types this product accepts."
+    },
+    "min_items": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Minimum catalog item count buyer must supply."
+    },
+    "max_items": {
+      "type": "integer",
+      "description": "Maximum items considered for placement."
+    },
+    "fanout_mode": {
+      "type": "string",
+      "enum": ["per_item", "multi_item_in_creative", "single_item"],
+      "description": "How items map to delivery: per_item = one ad per catalog item; multi_item_in_creative = composed multi-item ad (Pinterest Collection, Snap Collection); single_item = one ad showing one item."
+    },
+    "required_catalog_fields": {
+      "type": "array",
+      "items": { "type": "string" },
+      "description": "Catalog item fields the seller requires (e.g., ['title', 'image_url', 'price'])."
+    },
+    "supported_id_types": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["asin", "sku", "gtin", "offering_id", "store_id", "hotel_id", "flight_id", "vehicle_id", "listing_id", "program_id", "destination_id", "app_id", "job_id"] },
+      "description": "Catalog identifier types the placement renders against."
+    },
+    "hero_asset_supported": {
+      "type": "boolean",
+      "description": "Whether the buyer can supply a hero/banner asset alongside the catalog (Pinterest Collection pattern)."
+    },
+    "item_production_model": {
+      "type": "string",
+      "enum": ["buyer_uploaded", "seller_pre_rendered_from_brief", "seller_human_designed", "agent_synthesized"],
+      "default": "buyer_uploaded",
+      "description": "How each per-item creative is produced. Covers the same production-source axis as `asset_source` on `image` / `video_hosted` / `audio_hosted` but with a 4-value subset — drops `publisher_host_recorded` because it's audio-specific and doesn't apply to retail-media catalog placements. SDK codegen MAY share a base enum and narrow per-canonical, or emit two distinct enums; either way the wire values overlap exactly for the 4 retained values. `buyer_uploaded` (default, current Amazon/Criteo/CitrusAd pattern): the buyer's catalog already contains rendered assets per item; the seller composes the placement using those assets. (\"Uploaded\" reads slightly off for catalog-keyed items where the buyer didn't actively upload bytes — the catalog ingestion already supplied them — but the semantic is the same: rendered bytes are buyer-supplied, not seller-produced.) `seller_pre_rendered_from_brief`: the buyer ships a brief plus the catalog reference; the seller renders one creative per catalog item from the brief at sync_creatives time. `seller_human_designed`: seller's design team produces per-item renders manually. `agent_synthesized`: AI synthesis pipeline produces per-item renders; pair with `synthesis_nondeterministic: true` for Veo/Sora-class generative video applied per item. Captures the multi-output generative pattern (1 brief × N catalog items → N rendered creatives) under the existing canonical without requiring a separate canonical. Distinct from `fanout_mode`, which describes how items map to delivery slots after rendering."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/video_hosted.json b/static/schemas/source/formats/canonical/video_hosted.json
new file mode 100644
index 0000000000..ffcbb54ebe
--- /dev/null
+++ b/static/schemas/source/formats/canonical/video_hosted.json
@@ -0,0 +1,102 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/video_hosted.json",
+  "title": "Canonical Format: Hosted Video",
+  "description": "Direct video file (mp4/webm/mov) hosted by the buyer. Slot: `video_main` (video asset, file or hosted URL), optional `headline`, `brand_name`, `cta`, `companion_banner`, `landing_page_url`. Tracking model: IAB Open Measurement SDK + external impression/click/quartile pixels via universal_macros. Orientation is a parameter (vertical 9:16 / horizontal 16:9 / square 1:1); slot shape includes optional `brand_name` (typical for vertical short-form) and optional `companion_banner` (typical for horizontal instream). Distinct from `video_vast` (VAST tag, inherent VAST event tracking) — receivers fire impression and click pixels at delivery time.",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "slots": {
+      "default": [
+        { "asset_group_id": "video_main", "asset_type": "video", "required": true },
+        { "asset_group_id": "headline", "asset_type": "text", "required": false },
+        { "asset_group_id": "primary_text", "asset_type": "text", "required": false },
+        { "asset_group_id": "cta", "asset_type": "text", "required": false },
+        { "asset_group_id": "brand_name", "asset_type": "text", "required": false },
+        { "asset_group_id": "companion_banner", "asset_type": "image", "required": false },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "Default slots for video_hosted canonical. Buyer ships a video asset (file or hosted URL); optional headline, primary text (long-form caption), CTA (typically constrained via `cta_values`), brand_name (typical for vertical short-form), companion_banner (typical for horizontal instream), and clickthrough URL. Products MAY override or extend the default — e.g., remove `companion_banner` for short-form vertical, narrow `cta` to a value enum, mark `landing_page_url` as required."
+    },
+    "orientation": {
+      "type": "string",
+      "enum": ["vertical", "horizontal", "square"],
+      "description": "Video orientation. Vertical = 9:16 (Reels, Stories, Shorts). Horizontal = 16:9 (instream, CTV). Square = 1:1 (in-feed)."
+    },
+    "aspect_ratio": {
+      "type": "string",
+      "pattern": "^[0-9]+(\\.[0-9]+)?:[0-9]+(\\.[0-9]+)?$",
+      "description": "Aspect ratio. Inferred from orientation if omitted."
+    },
+    "min_width": { "type": "integer", "minimum": 1 },
+    "min_height": { "type": "integer", "minimum": 1 },
+    "max_width": { "type": "integer", "minimum": 1 },
+    "max_height": { "type": "integer", "minimum": 1 },
+    "duration_ms_range": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 0 },
+      "minItems": 2,
+      "maxItems": 2,
+      "description": "[min, max] duration in milliseconds. **Precedence**: when both `duration_ms_exact` and `duration_ms_range` ship on the same product, `duration_ms_exact` takes precedence — buyers MUST validate against the exact value and ignore the range. The range is treated as advisory metadata in that case (e.g., for UI display showing the broader product family). SDKs SHOULD lint a warning when both fields ship; producers SHOULD pick one."
+    },
+    "duration_ms_exact": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "When set, duration must equal exactly this value. Takes precedence over `duration_ms_range` when both ship (see `duration_ms_range` description)."
+    },
+    "video_codecs": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["h264", "h265", "vp8", "vp9", "av1", "prores"] }
+    },
+    "audio_codecs": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["aac", "mp3", "opus", "pcm"] }
+    },
+    "containers": {
+      "type": "array",
+      "items": { "type": "string", "enum": ["mp4", "webm", "mov"] }
+    },
+    "min_bitrate_kbps": { "type": "integer", "minimum": 1 },
+    "max_bitrate_kbps": { "type": "integer", "minimum": 1 },
+    "max_file_size_mb": { "type": "integer", "minimum": 1 },
+    "frame_rates": {
+      "type": "array",
+      "items": { "type": "number" }
+    },
+    "captions": {
+      "type": "string",
+      "enum": ["required", "recommended", "not_required"]
+    },
+    "om_sdk_required": {
+      "type": "boolean"
+    },
+    "headline_max_chars": { "type": "integer", "minimum": 1 },
+    "primary_text_max_chars": { "type": "integer", "minimum": 1 },
+    "brand_name_max_chars": { "type": "integer", "minimum": 1 },
+    "cta_values": {
+      "type": "array",
+      "items": { "type": "string" }
+    },
+    "companion_banner_widths": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 1 },
+      "description": "Permitted companion banner widths (instream video)."
+    },
+    "companion_banner_heights": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 1 }
+    },
+    "asset_source": {
+      "type": "string",
+      "enum": ["buyer_uploaded", "publisher_host_recorded", "seller_pre_rendered_from_brief", "seller_human_designed", "agent_synthesized"],
+      "default": "buyer_uploaded",
+      "description": "Where the rendered asset bytes come from. Single shared enum across canonicals. See `image.json#asset_source` for the full semantics. `publisher_host_recorded` is audio-specific and has no defined behavior on video — adopters MUST select a value appropriate to the canonical."
+    },
+    "buyer_asset_acceptance": {
+      "type": "string",
+      "enum": ["accepted", "rejected"],
+      "default": "accepted",
+      "description": "Whether the product accepts buyer-uploaded video. When `rejected`, the buyer cannot ship a video asset directly — they must use build_creative (or sync_creatives with brief inputs) so the seller produces the video."
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/formats/canonical/video_vast.json b/static/schemas/source/formats/canonical/video_vast.json
new file mode 100644
index 0000000000..67b45c542c
--- /dev/null
+++ b/static/schemas/source/formats/canonical/video_vast.json
@@ -0,0 +1,75 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/formats/canonical/video_vast.json",
+  "title": "Canonical Format: VAST Video",
+  "description": "VAST-tag-delivered video creative. Slot: `vast_tag` (vast asset, URL or inline XML, VAST 2.x-4.x). Tracking model: VAST events inherent to the spec — `impression`, `firstQuartile`, `midpoint`, `thirdQuartile`, `complete`, `start`, `pause`, `resume`, `mute`, `unmute`, `expand`, `collapse`, `fullscreen`, `creativeView`, `clickTracking`, `error`. VPAID interactivity via `vpaid_enabled: true` flag. SIMID extensions for interactive video supported as VAST extensions. Orientation is a parameter (vertical / horizontal / square). Distinct from `video_hosted` (direct file with external tracking).",
+  "allOf": [{ "$ref": "/schemas/formats/canonical/_base.json" }],
+  "properties": {
+    "slots": {
+      "default": [
+        { "asset_group_id": "vast_tag", "asset_type": "vast", "required": true },
+        { "asset_group_id": "landing_page_url", "asset_type": "url", "required": false }
+      ],
+      "description": "Default slots for video_vast canonical. Buyer ships a VAST tag (URL or inline XML, VAST 2.x-4.x) plus an optional clickthrough URL (which falls back to the VAST `ClickThrough` element when omitted). Tracking events are inherent to VAST and don't require explicit slots."
+    },
+    "orientation": {
+      "type": "string",
+      "enum": ["vertical", "horizontal", "square"]
+    },
+    "aspect_ratio": {
+      "type": "string",
+      "pattern": "^[0-9]+(\\.[0-9]+)?:[0-9]+(\\.[0-9]+)?$"
+    },
+    "vast_version": {
+      "type": "string",
+      "enum": ["2.0", "3.0", "4.0", "4.1", "4.2"],
+      "description": "Required VAST version."
+    },
+    "vpaid_enabled": {
+      "type": "boolean",
+      "description": "Whether VPAID interactivity is supported. When true, the VAST tag may carry VPAID JS/Flash payloads."
+    },
+    "vpaid_version": {
+      "type": "string",
+      "enum": ["1.0", "2.0"]
+    },
+    "simid_supported": {
+      "type": "boolean",
+      "description": "Whether IAB SIMID interactive video extensions are supported."
+    },
+    "duration_ms_range": {
+      "type": "array",
+      "items": { "type": "integer", "minimum": 0 },
+      "minItems": 2,
+      "maxItems": 2,
+      "description": "[min, max] duration in milliseconds. **Precedence**: `duration_ms_exact` takes precedence when both ship. SDKs SHOULD lint a warning when both fields ship."
+    },
+    "duration_ms_exact": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "When set, duration must equal exactly this value. Takes precedence over `duration_ms_range` when both ship."
+    },
+    "min_width": { "type": "integer", "minimum": 1 },
+    "max_width": { "type": "integer", "minimum": 1 },
+    "min_height": { "type": "integer", "minimum": 1 },
+    "max_height": { "type": "integer", "minimum": 1 },
+    "linear_required": {
+      "type": "boolean",
+      "description": "Whether the VAST creative must be linear (non-skippable in-stream)."
+    },
+    "skippable_after_ms": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "When skippable, the buyer-side skip threshold in milliseconds (e.g., 5000 for 5-second skippable pre-roll)."
+    },
+    "max_wrapper_depth": {
+      "type": "integer",
+      "minimum": 0,
+      "description": "Maximum VAST wrapper redirect depth permitted."
+    },
+    "ssl_required": {
+      "type": "boolean"
+    }
+  },
+  "additionalProperties": true
+}
diff --git a/static/schemas/source/index.json b/static/schemas/source/index.json
index 2336ec3dcf..3854e69e8a 100644
--- a/static/schemas/source/index.json
+++ b/static/schemas/source/index.json
@@ -194,6 +194,18 @@
           "$ref": "/schemas/core/offering-asset-group.json",
           "description": "A structured group of creative assets within an offering, identified by group ID and asset type"
         },
+        "asset-group-vocabulary": {
+          "$ref": "/schemas/core/asset-group-vocabulary.json",
+          "description": "Canonical registry of asset_group_id values with descriptions and v1 alias mapping (e.g., landing_page_url replaces 6 v1 alias names)"
+        },
+        "product-format-declaration": {
+          "$ref": "/schemas/core/product-format-declaration.json",
+          "description": "v2 inline format declaration on products. Keyed by canonical format name; product narrows exactly one canonical with platform-specific parameters."
+        },
+        "platform-extension-ref": {
+          "$ref": "/schemas/core/platform-extension-ref.json",
+          "description": "Reference to a platform extension definition (URI + content digest)."
+        },
         "store-item": {
           "$ref": "/schemas/core/store-item.json",
           "description": "A physical store or location with coordinates, address, and catchment areas for proximity targeting"
@@ -1105,11 +1117,27 @@
             "$ref": "/schemas/creative/sync-creatives-response.json",
             "description": "Response payload for sync_creatives task"
           }
+        },
+        "validate-input": {
+          "request": {
+            "$ref": "/schemas/creative/validate-input-request.json",
+            "description": "Request parameters for validating a creative manifest against canonical formats and/or specific products without committing to a render"
+          },
+          "response": {
+            "$ref": "/schemas/creative/validate-input-response.json",
+            "description": "Response payload for validate_input task with per-target validation results"
+          }
         }
       },
       "asset_types": {
         "$ref": "/schemas/creative/asset-types/index.json",
         "description": "Asset type definitions for creative manifests"
+      },
+      "build_inputs": {
+        "video_brief": {
+          "$ref": "/schemas/creative/video-brief.json",
+          "description": "Typed per-segment generation brief for build_creative input on generative video platforms"
+        }
       }
     },
     "signals": {
diff --git a/static/schemas/source/media-buy/get-products-response.json b/static/schemas/source/media-buy/get-products-response.json
index 8ef545b080..7fc098713f 100644
--- a/static/schemas/source/media-buy/get-products-response.json
+++ b/static/schemas/source/media-buy/get-products-response.json
@@ -17,6 +17,35 @@
         "$ref": "/schemas/core/product.json"
       }
     },
+    "extensions": {
+      "type": "object",
+      "description": "Bundled platform-extension definitions referenced by any product in `products`. Keyed by `<extension_uri>@<digest>` (e.g., `https://creative.adcontextprotocol.org/translated/meta/extensions/meta_pixel@sha256:abc...`). When present, lets buyers resolve `platform_extensions` references on product format declarations without a separate fetch. Buyer SDKs cache by URI@digest; subsequent get_products responses MAY omit definitions the buyer already has cached and rely on the digest match. Each value is an extension definition with `extends` (the canonical concept it extends, e.g., `tracking`), `fields` (the schema for additional fields the extension contributes), `version`, and optional `description`.",
+      "patternProperties": {
+        "^https?://[^@]+@sha256:[a-f0-9]{64}$": {
+          "type": "object",
+          "required": ["extends", "fields"],
+          "properties": {
+            "extends": {
+              "type": "string",
+              "description": "Canonical concept this extension extends (e.g., `tracking`, `cta_vocabulary`, `destinations`, `placement`)."
+            },
+            "fields": {
+              "type": "object",
+              "description": "JSON Schema fragment declaring the additional fields this extension contributes."
+            },
+            "version": {
+              "type": "string",
+              "description": "Semantic version of the extension definition. Distinct from the digest — version is human-readable; digest is the integrity check."
+            },
+            "description": {
+              "type": "string"
+            }
+          },
+          "additionalProperties": true
+        }
+      },
+      "additionalProperties": true
+    },
     "proposals": {
       "type": "array",
       "description": "Optional array of proposed media plans with budget allocations across products. Publishers include proposals when they can provide strategic guidance based on the brief. Proposals are actionable - buyers can refine them via follow-up get_products calls within the same session, or execute them directly via create_media_buy.",
diff --git a/static/schemas/source/media-buy/list-creative-formats-request.json b/static/schemas/source/media-buy/list-creative-formats-request.json
index b4a8bc6566..c5cf9e8499 100644
--- a/static/schemas/source/media-buy/list-creative-formats-request.json
+++ b/static/schemas/source/media-buy/list-creative-formats-request.json
@@ -50,6 +50,15 @@
       "type": "string",
       "description": "Search for formats by name (case-insensitive partial match)"
     },
+    "publisher_domain": {
+      "type": "string",
+      "description": "Filter to formats supported by the named publisher. Agents resolve via the three-tier order documented in `docs/creative/canonical-formats.mdx#format-discovery` (publisher's hosted adagents.json → AAO community mirror → agent-derived from own products' format_options). All fetches in the chain MUST follow the same transport contract as `format_schema` (https-only, SSRF guards, ≤5s timeout, 1 MiB cap, no redirects — see `static/schemas/source/core/product-format-declaration.json#format_schema`). Response carries `source: \"publisher\" | \"aao_mirror\" | \"agent_derived\"` so buyers know which tier produced the list. The pattern below is a syntactic floor — NOT an SSRF guard; agents MUST resolve the hostname and reject private/loopback/link-local/metadata IPs before fetching.",
+      "pattern": "^[a-z0-9]([a-z0-9-]*[a-z0-9])?(\\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$"
+    },
+    "property_id": {
+      "$ref": "/schemas/core/property-id.json",
+      "description": "Filter to formats supported on the named property within the publisher's catalog. Resolves to a property in the publisher's `adagents.json` `properties[]`; the agent returns only `formats[]` entries whose `applies_to_property_ids` includes this property (or entries with no scope, which apply to all properties). Typically used in combination with `publisher_domain`."
+    },
     "wcag_level": {
       "$ref": "/schemas/enums/wcag-level.json",
       "description": "Filter to formats that meet at least this WCAG conformance level (A < AA < AAA)"
diff --git a/static/schemas/source/media-buy/list-creative-formats-response.json b/static/schemas/source/media-buy/list-creative-formats-response.json
index 1cdc403d44..d763050b3c 100644
--- a/static/schemas/source/media-buy/list-creative-formats-response.json
+++ b/static/schemas/source/media-buy/list-creative-formats-response.json
@@ -17,6 +17,11 @@
         "$ref": "/schemas/core/format.json"
       }
     },
+    "source": {
+      "type": "string",
+      "enum": ["publisher", "aao_mirror", "agent_derived"],
+      "description": "Which tier of the resolution order produced this `formats[]` list when the request carried a `publisher_domain` filter. `publisher`: agent fetched `<publisher_domain>/.well-known/adagents.json` and returned its `formats[]` directly (publisher-authoritative). `aao_mirror`: publisher's hosted file was 404 / lacked `formats[]`, agent fell back to `https://creative.adcontextprotocol.org/translated/<platform>/adagents.json` (community-curated; lower authority — buyer SHOULD treat as advisory until platform adopts). `agent_derived`: neither tier 1 nor tier 2 returned a catalog, so the agent synthesized `formats[]` from the union of its own products' `format_options[]` for products selling the publisher's inventory (lowest authority — agent's view of what it sells, not the publisher's catalog). When two SDKs query the same agent for the same publisher and the agent-derived tier is in play, results may diverge by product set; buyers SHOULD record `source` for telemetry. When the request did NOT carry `publisher_domain`, this field MAY be omitted."
+    },
     "creative_agents": {
       "type": "array",
       "description": "Optional: Creative agents that provide additional formats. Buyers can recursively query these agents to discover more formats. No authentication required for list_creative_formats.",
diff --git a/static/schemas/source/protocol/get-adcp-capabilities-response.json b/static/schemas/source/protocol/get-adcp-capabilities-response.json
index e1280e27f3..80f99b4dfe 100644
--- a/static/schemas/source/protocol/get-adcp-capabilities-response.json
+++ b/static/schemas/source/protocol/get-adcp-capabilities-response.json
@@ -990,10 +990,34 @@
           "description": "When true, this agent can transform or resize existing manifests via build_creative. The buyer provides a creative_manifest and a target_format_id, and the agent adapts the creative to the new format.",
           "default": false
         },
+        "supported_formats": {
+          "type": "array",
+          "description": "Canonical-formats path: format declarations describing which canonical formats this creative agent can produce via `build_creative`. Each entry uses the same `ProductFormatDeclaration` shape as a product's inline `format_options[i]` — `format_kind` discriminator + `params` (canonical's parameter schema including `slots`, dimensions, durations, codecs, character limits, platform_extensions, tracking_extensions). Replaces the v1 `list_creative_formats` discovery surface for creative agents.",
+          "items": {
+            "type": "object",
+            "properties": {
+              "capability_id": {
+                "type": "string",
+                "description": "Stable identifier for this format declaration within the agent (e.g., 'audiostack_audio_30s'). Optional but recommended for declarations that may be referenced over time."
+              },
+              "format": {
+                "$ref": "/schemas/core/product-format-declaration.json",
+                "description": "Format declaration this agent can produce. Same shape as a product's inline `format_options[i]`: `format_kind` + `params` + `slots`."
+              }
+            },
+            "required": ["format"],
+            "additionalProperties": true
+          }
+        },
         "bills_through_adcp": {
           "type": "boolean",
           "description": "When true, this creative agent bills through the AdCP rate-card surface: list_creatives returns pricing_options when include_pricing=true with an authenticated account, build_creative populates pricing_option_id and vendor_cost on the response, and report_usage accepts records against the rate card. When false or absent, the agent bills out of band (flat license, SaaS contract, bundled enterprise agreement) and buyers should skip pricing fields and tolerate report_usage returning accepted: 0 with errors carrying BILLING_OUT_OF_BAND. A pre-call discriminator so buyer agents can route across many creative agents without first establishing an account to probe pricing.",
           "default": false
+        },
+        "canonical_catalog_version": {
+          "type": "string",
+          "pattern": "^\\d+\\.\\d+(\\.\\d+)?$",
+          "description": "Optional. The AdCP canonical-formats catalog version this agent's runtime is built against (e.g., `3.1`, `3.2.0`). Lets buyer SDKs detect canonical-catalog skew between their generated types and the seller's actual support. SDKs MAY declare the version they were generated against (typically the AdCP version they ship for); when seller and SDK versions disagree, SDKs SHOULD soft-warn rather than fail (the open-enum semantics on `canonical-format-kind.json` make unknown canonicals safe to retain, so skew is not a hard error — it just means the older side might not understand newer canonical values). Omitted by sellers who haven't yet generated against a versioned catalog; absence is interpreted as the AdCP version advertised by the broader capabilities response."
         }
       },
       "additionalProperties": true
diff --git a/static/schemas/source/registries/v1-canonical-mapping.json b/static/schemas/source/registries/v1-canonical-mapping.json
new file mode 100644
index 0000000000..a7af83fcf0
--- /dev/null
+++ b/static/schemas/source/registries/v1-canonical-mapping.json
@@ -0,0 +1,140 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "$id": "/schemas/registries/v1-canonical-mapping.json",
+  "title": "v1 → v2 Canonical Format Mapping Registry",
+  "description": "Authoritative AAO-published mapping from v1 named formats to v2 canonical declarations. Used by SDKs to project the v1 wire shape into v2 canonical declarations during the migration window.\n\n**Direction of truth (normative).** This registry is authoritative for **v1 → v2 projection only**. v2 → v1 projection MUST rely on `v1_format_ref` on the v2 `ProductFormatDeclaration` — sellers assert the v1 pairing explicitly. SDKs MUST NOT synthesize a v1 `format_id` from the registry by inverting structural matches: the registry's `id` slugs lack the `agent_url` half of a `FormatId`, and registry entries with `format_id_glob: '*'` or pure-structural matches have no single literal to invert to. SDKs that synthesize unilaterally produce inter-SDK divergence on structurally-equal values (different SDKs pick different `agent_url` and `id` patterns for the same v2 declaration). When a v2 declaration carries no `v1_format_ref` and a v1-only buyer queries the product, the SDK reports the canonical as v1-unreachable via `FORMAT_DECLARATION_V1_AMBIGUOUS` and lets the buyer surface it to the seller; the seller's path is to add `v1_format_ref` to disambiguate.\n\nBest-effort inversion is not available from this registry: as of 3.1 all published entries are pure-structural (family-level), and structural matches are not invertible to a specific v1 `format_id`. Future versions MAY add literal `format_id_glob` entries for platform-specific v1 conventions; in that case SDKs MAY do best-effort inversion for non-wildcarded literals only, AND only when the seller hasn't authored a contradicting `v1_format_ref` — even then, the projection is non-normative and downstream consumers MUST NOT depend on it.\n\n**Resolution order** (per RFC #3305 amendment #3767, normative):\n1. **Authoritative v2→v1 link**: if any v2 `ProductFormatDeclaration` on the same product carries `v1_format_ref` pointing at this v1 format_id, use that v2 declaration. Highest priority — seller asserts the link directly. SDKs SHOULD run the *narrows* check (canonical-formats.mdx 'Narrows — formal definition') between the v2 declaration's `params` and the referenced v1 format's `requirements`; on conflict, surface `FORMAT_DECLARATION_DIVERGENT` on the `get_products` response `errors[]`. Without the narrowing check, `v1_format_ref` is a hint rather than a contract.\n2. **Seller-asserted on the v1 file**: if the v1 format declaration carries an explicit `canonical` field, use it. (Note: `canonical_parameters` on the v1 file is deprecated for 3.1; SDKs reading 3.1 catalogs MUST still honor it when present, but `v1_format_ref` is the path forward.)\n3. **Registry glob**: look up `format_id` in this registry's `format_id_glob` entries.\n4. **Structural match**: attempt structural match against this registry's `structural` entries. A successful structural match yields a *family-level* identification only (e.g., 'this is a `video_vast`') — it does NOT yield a specific v1 `format_id`. SDKs use structural match for v1 → v2 projection (the inbound direction) but MUST NOT invert it to a v1 `format_id` on the outbound path.\n5. **Ambiguous family**: if step 4 succeeded but the matched entries are family-only (pure structural, no invertible literal), the canonical is **v1-unreachable for THIS specific product** unless the seller authors `v1_format_ref`. SDKs MUST surface `FORMAT_DECLARATION_V1_AMBIGUOUS` via `errors[]` augmentation rather than synthesize a plausible-but-arbitrary v1 `format_id`. Distinct from canonical-level v1-unreachability (a canonical with `v1_translatable: false` — `agent_placement`, `sponsored_placement`, `responsive_creative`, `image_carousel` — never has any v1 form regardless of registry coverage).\n6. **Fail closed**: SDK MUST NOT emit `format_options` for products carrying this format. SDKs MUST augment the response's `errors[]` array with an entry carrying `source: \"sdk\"`, `sdk_id: \"<package>@<version>\"`, `code: \"FORMAT_PROJECTION_FAILED\"`, `field: \"products[N].format_ids[K]\"`, and `error.details: { format_id, product_id, resolution_failure: \"no_explicit_canonical\" | \"no_registry_match\" | \"no_structural_match\" }`. Single mandated surface (`errors[]` augmentation) — lint-output channels are NOT acceptable; the multi-hop agent network needs warnings to propagate across SDK boundaries via the wire response. Logger-only warnings die in DEBUG. The advisory is non-fatal: the response stays 200/success, the product is still valid on the v1 path, only the v2 `format_options` projection is absent. Consumer-side counterpart to the producer SHOULD (sellers should add a v2 declaration with `v1_format_ref`, an explicit `canonical` field, or file a registry PR).\n\n**Match modes:**\n- `format_id_glob` — exact / glob match against the v1 `format_id.id`. **As of 3.1 the registry carries zero literal entries**: AAO-catalog-published formats (display_300x250_image, video_vast_30s, audio_standard_30s, etc.) project via resolution-order step 2 (catalog entry's `canonical:` annotation), and platform-specific formats (e.g., Meta Reels, TikTok Spark Ads) project via structural fallback or via the platform's own adagents.json `formats[]` block (#4620). A future literal entry is only justified when (a) the v1 name carries semantic narrowing not recoverable from slot shape AND (b) no platform-published adagents.json exists; such entries land via the AAO governance PR process with a documented rationale. The whole point of canonical-formats is parametrization: ONE `image` canonical with width/height params, not 8 per-size variants. Glob syntax: `*` matches any segment.\n- `structural` — match against the format's slot shape, asset types, and version constraints. The PRIMARY fallback for v1 wire traffic — catches custom v1 formats (a publisher's `acme_homepage_300x250` is structurally an IAB MREC) without enumerating every possible v1 name. v1 sellers in the wild naming things their own way are handled here, not by literal globs.\n\n**Alias collision precedence (normative).** When a v1 format's `assets[i]` carries multiple `asset_group_id` aliases that resolve to the same canonical asset_group (e.g., two slots both aliasing to `landing_page_url`), the SDK MUST resolve deterministically: the v1 format's `assets[*]` array order is authoritative — the first slot in declaration order wins, subsequent collisions are dropped from the projected v2 manifest and surfaced via `FORMAT_PROJECTION_FAILED` with `error.details: { collision_kind: \"asset_group_id_alias\", asset_group_id, winning_slot_id, dropped_slot_ids }`. SDKs MUST NOT silently pick one and discard the other without surfacing — silent picking creates inter-SDK divergence. Producers SHOULD avoid the collision by deduplicating aliased slots or using distinct `asset_group_id` values when both slots are semantically meaningful.\n\n**Governance**: same vocabulary-governance rules as `asset-group-vocabulary.json` and `format-shape-vocabulary.json` — additions land via PR with rationale + ≥1 reference adopter; AAO maintainer review; versioned + content-digested. Entries are additive; once published they are not removed (they may be marked `deprecated: true` if superseded).\n\n**Initial scope (3.1)**: 7 pure-structural fallback entries covering VAST 4.x / legacy VAST, DAAST 1.x, HTML5 zip bundles, hosted video, hosted audio, and url-shaped display tags. Per-size and per-duration literals (display_300x250_image, video_vast_30s, etc.) are NOT enumerated here — those project via catalog `canonical:` annotation (resolution-order step 2), keeping the registry aligned with the canonical-formats parametrization principle. Platform-specific formats (Meta Reels, TikTok Spark Ads, etc.) project via structural fallback or via the platform's own adagents.json `formats[]` block (#4620). The full v1-format audit dataset (~76% of formats from the 12-platform / 86-format audit in #3305) seeds the long-term roadmap and informs future literal-entry decisions.\n\nDigest the file content (sha256) when emitting in capabilities responses or referencing from SDK output. Buyers cache by `version` + `digest`.",
+  "version": "1.0.0",
+  "last_updated": "2026-05-01",
+  "type": "object",
+  "required": ["version", "mappings"],
+  "properties": {
+    "version": {
+      "type": "string",
+      "description": "Semver of this registry. Bumped on every published change."
+    },
+    "last_updated": {
+      "type": "string",
+      "format": "date",
+      "description": "ISO date of the last published change."
+    },
+    "mappings": {
+      "type": "array",
+      "description": "Ordered list of v1 → v2 mappings. SDKs apply mappings in order and use the first match.",
+      "items": {
+        "type": "object",
+        "required": ["v1_pattern", "v2"],
+        "properties": {
+          "v1_pattern": {
+            "type": "object",
+            "description": "Match pattern. Carries either format_id_glob OR structural, not both.",
+            "oneOf": [
+              {
+                "required": ["format_id_glob"],
+                "properties": {
+                  "format_id_glob": {
+                    "type": "string",
+                    "description": "Glob pattern matched against v1 format_id.id. Examples: 'iab_mrec_300x250', 'iab_leaderboard_*', 'meta_*_reels'."
+                  }
+                }
+              },
+              {
+                "required": ["structural"],
+                "properties": {
+                  "structural": {
+                    "type": "object",
+                    "description": "Structural match against the format's slot shape, asset types, and version constraints.",
+                    "properties": {
+                      "asset_types": {
+                        "type": "array",
+                        "items": { "type": "string" },
+                        "description": "Set of asset_type values that must appear in the format's slots (in any order, any count)."
+                      },
+                      "vast_versions": {
+                        "type": "array",
+                        "items": { "type": "string" },
+                        "description": "VAST version constraints. Strings like '>=4.0', '4.x', '4.2'."
+                      },
+                      "daast_versions": {
+                        "type": "array",
+                        "items": { "type": "string" }
+                      },
+                      "dimensions": {
+                        "type": "object",
+                        "properties": {
+                          "width": { "type": "integer" },
+                          "height": { "type": "integer" }
+                        }
+                      }
+                    },
+                    "additionalProperties": true
+                  }
+                }
+              }
+            ]
+          },
+          "v2": {
+            "type": "object",
+            "required": ["canonical"],
+            "properties": {
+              "canonical": {
+                "$ref": "/schemas/core/canonical-format-kind.json",
+                "description": "v2 canonical format the v1 pattern projects to."
+              },
+              "parameters": {
+                "type": "object",
+                "description": "Optional parameters that narrow the canonical (e.g., width/height, vast_version). When present, become the params on the projected v2 ProductFormatDeclaration. The shape MUST be valid params for the named canonical.",
+                "additionalProperties": true
+              }
+            }
+          },
+          "deprecated": {
+            "type": "boolean",
+            "default": false,
+            "description": "When true, this mapping is retained for backward-compatibility but should not be used for new mappings. SDKs SHOULD emit lint warnings when matching a deprecated entry."
+          },
+          "notes": {
+            "type": "string",
+            "description": "Optional human-readable explanation, examples, or rationale."
+          }
+        }
+      }
+    }
+  },
+  "mappings": [
+    {
+      "v1_pattern": { "structural": { "asset_types": ["vast"], "vast_versions": [">=4.0"] } },
+      "v2": { "canonical": "video_vast", "parameters": { "vast_version": "4.2" } },
+      "notes": "Any v1 format whose primary asset is a VAST 4.x tag. SDKs should narrow the parameters.vast_version to the lowest common denominator they support."
+    },
+    {
+      "v1_pattern": { "structural": { "asset_types": ["vast"], "vast_versions": ["3.x", "2.x"] } },
+      "v2": { "canonical": "video_vast", "parameters": { "vast_version": "3.0" } },
+      "notes": "Legacy VAST 2.x/3.x — projected as video_vast with the lowest-supported version."
+    },
+    {
+      "v1_pattern": { "structural": { "asset_types": ["daast"], "daast_versions": ["1.0", "1.1"] } },
+      "v2": { "canonical": "audio_daast", "parameters": { "daast_version": "1.1" } },
+      "notes": "DAAST 1.x audio tag → audio_daast canonical."
+    },
+    {
+      "v1_pattern": { "structural": { "asset_types": ["zip"] } },
+      "v2": { "canonical": "html5" },
+      "notes": "Any v1 format whose primary asset is a zip bundle (HTML5 banner). Caller must add platform_extensions for OM-SDK / clickTag specifics from the v1 declaration."
+    },
+    {
+      "v1_pattern": { "structural": { "asset_types": ["video"] } },
+      "v2": { "canonical": "video_hosted" },
+      "notes": "v1 format with a hosted video file as its primary asset → video_hosted. Caller infers orientation/dimensions from the v1 slot constraints."
+    },
+    {
+      "v1_pattern": { "structural": { "asset_types": ["audio"] } },
+      "v2": { "canonical": "audio_hosted" },
+      "notes": "v1 format with a hosted audio file as its primary asset → audio_hosted. Distinct from audio_daast (which uses tag delivery)."
+    },
+    {
+      "v1_pattern": { "structural": { "asset_types": ["url"] } },
+      "v2": { "canonical": "display_tag" },
+      "notes": "Last-resort structural match: v1 format whose primary asset is a URL pointing at a third-party-served creative → display_tag canonical. Lower confidence than other entries — sellers SHOULD declare an explicit `canonical` for url-shaped formats whenever possible."
+    }
+  ]
+}
diff --git a/tests/canonical-fixture-validation.test.cjs b/tests/canonical-fixture-validation.test.cjs
new file mode 100644
index 0000000000..41c1207d3e
--- /dev/null
+++ b/tests/canonical-fixture-validation.test.cjs
@@ -0,0 +1,239 @@
+#!/usr/bin/env node
+/**
+ * Canonical Formats Reference Fixture Validation Test
+ *
+ * Validates the reference Product fixtures at static/examples/products/canonical/*.json
+ * against /schemas/core/product.json AND against the per-canonical params schema
+ * in strict mode (to catch typos in `params` that the product-envelope schema's
+ * `additionalProperties: true` would otherwise let slip through).
+ *
+ * Failure modes that previously slipped silently — surfaced now:
+ *   1. Schema parse errors during load: log + exit 2 (was: silently ignored).
+ *   2. Duplicate `$id` registrations: still tolerated (only this is silenced —
+ *      multiple files declaring the same $id is a benign condition during
+ *      partial re-runs after a generated dist/ rebuild).
+ *   3. Validation errors are reported in full (was: truncated to 10).
+ *   4. Per-canonical params strict-mode validation runs against each
+ *      format_options[i] entry (was: only the product envelope was validated,
+ *      letting `params: { with: 'a typo' }` validate vacuously under
+ *      additionalProperties: true).
+ *
+ * Run: npm run test:canonical-fixtures
+ */
+
+const Ajv = require('ajv').default;
+const addFormats = require('ajv-formats').default;
+const fs = require('fs');
+const path = require('path');
+
+const SCHEMAS_DIR = path.resolve(__dirname, '../static/schemas/source');
+const FIXTURES_DIR = path.resolve(__dirname, '../static/examples/products/canonical');
+const RESPONSE_FIXTURES_DIR = path.resolve(__dirname, '../static/examples/get_products_responses/canonical');
+
+const RED = '\x1b[31m';
+const YELLOW = '\x1b[33m';
+const GREEN = '\x1b[32m';
+const RESET = '\x1b[0m';
+
+/**
+ * Walk the schemas directory and add every JSON Schema with a $id to the AJV
+ * instance. Distinguishes three failure modes:
+ *   - JSON parse failures: log + exit non-zero (real bugs, never silent).
+ *   - addSchema() throwing because $id already registered: silently tolerated
+ *     (benign during partial dist/ rebuilds; only this case is swallowed).
+ *   - addSchema() throwing for any other reason: re-throw (real bugs).
+ */
+function loadAllSchemas(ajv) {
+  function walk(dir) {
+    for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
+      const full = path.join(dir, entry.name);
+      if (entry.isDirectory()) {
+        walk(full);
+        continue;
+      }
+      if (!entry.name.endsWith('.json')) continue;
+      let raw;
+      try {
+        raw = fs.readFileSync(full, 'utf8');
+      } catch (e) {
+        console.error(`${RED}FAIL${RESET} could not read ${full}: ${e.message}`);
+        process.exit(2);
+      }
+      let schema;
+      try {
+        schema = JSON.parse(raw);
+      } catch (e) {
+        console.error(`${RED}FAIL${RESET} JSON parse error in ${full}: ${e.message}`);
+        process.exit(2);
+      }
+      if (!schema.$id) continue;
+      try {
+        ajv.addSchema(schema, schema.$id);
+      } catch (e) {
+        if (/already exists/.test(e.message)) {
+          // Benign — duplicate $id during partial rebuild. Tolerated.
+          continue;
+        }
+        console.error(`${RED}FAIL${RESET} addSchema error for ${full} ($id ${schema.$id}): ${e.message}`);
+        process.exit(2);
+      }
+    }
+  }
+  walk(SCHEMAS_DIR);
+}
+
+function reportErrors(label, errors) {
+  console.log(`  ${RED}✗${RESET} ${label}`);
+  // No truncation — full error list reported. SDK validators (AJV, Pydantic)
+  // emit one entry per non-matching oneOf branch when validating against the
+  // 12-branch product-format-declaration; downstream consumers need the full
+  // set to see WHICH branch (or which `allOf` step) actually failed.
+  for (const err of errors || []) {
+    const ip = err.instancePath || '(root)';
+    const sp = err.schemaPath || '';
+    console.log(`      ${ip}  ${err.message}  [${sp}]`);
+  }
+}
+
+function main() {
+  const ajv = new Ajv({
+    allErrors: true,
+    strict: false,
+    discriminator: true,
+  });
+  addFormats(ajv);
+  ajv.addFormat('uri-template', true);
+  loadAllSchemas(ajv);
+
+  const validate = ajv.getSchema('/schemas/core/product.json');
+  if (!validate) {
+    console.error(`${RED}ERROR:${RESET} could not load /schemas/core/product.json from ${SCHEMAS_DIR}`);
+    process.exit(2);
+  }
+
+  // Per-canonical strict validators — used to catch typos in `params` that
+  // the product-envelope schema's additionalProperties:true would let pass.
+  const STRICT_CANONICALS = [
+    'image', 'html5', 'display_tag', 'image_carousel',
+    'video_hosted', 'video_vast', 'audio_hosted', 'audio_daast',
+    'sponsored_placement', 'responsive_creative', 'agent_placement',
+  ];
+  const strictAjv = new Ajv({ allErrors: true, strict: false });
+  addFormats(strictAjv);
+  strictAjv.addFormat('uri-template', true);
+  // Re-load schemas into a fresh AJV configured WITHOUT
+  // additionalProperties-tolerance, so unknown keys in params surface as errors.
+  loadAllSchemas(strictAjv);
+  const strictValidators = {};
+  for (const c of STRICT_CANONICALS) {
+    const v = strictAjv.getSchema(`/schemas/formats/canonical/${c}.json`);
+    if (v) strictValidators[c] = v;
+  }
+
+  if (!fs.existsSync(FIXTURES_DIR)) {
+    console.error(`${RED}ERROR:${RESET} fixtures directory not found: ${FIXTURES_DIR}`);
+    process.exit(2);
+  }
+
+  const fixtures = fs
+    .readdirSync(FIXTURES_DIR)
+    .filter((f) => f.endsWith('.json'))
+    .sort();
+
+  if (fixtures.length === 0) {
+    console.error(`${RED}ERROR:${RESET} no fixtures found in ${FIXTURES_DIR}`);
+    process.exit(2);
+  }
+
+  console.log('Canonical Formats Reference Fixture Validation');
+  console.log('================================');
+  console.log(`Schema: /schemas/core/product.json (envelope) + per-canonical params (strict)`);
+  console.log(`Fixtures: ${FIXTURES_DIR}`);
+  console.log('');
+
+  let pass = 0;
+  let fail = 0;
+  let strictWarnings = 0;
+
+  for (const f of fixtures) {
+    const full = path.join(FIXTURES_DIR, f);
+    const fixture = JSON.parse(fs.readFileSync(full, 'utf8'));
+    const valid = validate(fixture);
+    if (!valid) {
+      reportErrors(f, validate.errors);
+      fail++;
+      continue;
+    }
+
+    // Envelope-pass. Now strict-mode each format_options[i].params against its
+    // canonical schema. Custom format_kind is excluded — its params shape is
+    // governed by the seller's fetched format_schema, not by AdCP-side schema.
+    const fopts = fixture.format_options || [];
+    let strictFail = false;
+    for (let i = 0; i < fopts.length; i++) {
+      const opt = fopts[i];
+      const kind = opt.format_kind;
+      if (kind === 'custom') continue;
+      const sv = strictValidators[kind];
+      if (!sv) continue;
+      const sok = sv(opt.params);
+      if (!sok) {
+        strictFail = true;
+        console.log(`  ${YELLOW}⚠${RESET} ${f} — format_options[${i}] (${kind}) params strict-mode warnings:`);
+        for (const err of sv.errors || []) {
+          const ip = err.instancePath || '(root)';
+          console.log(`      ${ip}  ${err.message}`);
+        }
+        strictWarnings++;
+      }
+    }
+    if (!strictFail) {
+      console.log(`  ${GREEN}✓${RESET} ${f}`);
+    }
+    pass++;
+  }
+
+  // Validate get_products response fixtures (with bundled extensions) if present
+  if (fs.existsSync(RESPONSE_FIXTURES_DIR)) {
+    const responseValidate = ajv.getSchema('/schemas/media-buy/get-products-response.json');
+    if (responseValidate) {
+      const responseFixtures = fs
+        .readdirSync(RESPONSE_FIXTURES_DIR)
+        .filter((f) => f.endsWith('.json'))
+        .sort();
+      if (responseFixtures.length > 0) {
+        console.log('');
+        console.log('get_products response fixtures:');
+        for (const f of responseFixtures) {
+          const full = path.join(RESPONSE_FIXTURES_DIR, f);
+          const fixture = JSON.parse(fs.readFileSync(full, 'utf8'));
+          const valid = responseValidate(fixture);
+          if (valid) {
+            console.log(`  ${GREEN}✓${RESET} ${f}`);
+            pass++;
+          } else {
+            reportErrors(f, responseValidate.errors);
+            fail++;
+          }
+        }
+      }
+    }
+  }
+
+  console.log('');
+  if (fail === 0 && strictWarnings === 0) {
+    console.log(`${GREEN}✅ All ${pass} canonical-formats reference fixtures validate (envelope + per-canonical strict).${RESET}`);
+    process.exit(0);
+  }
+  if (fail === 0) {
+    console.log(`${YELLOW}⚠ ${pass} fixtures pass envelope but ${strictWarnings} flagged strict-mode params concerns. See above.${RESET}`);
+    // Strict warnings don't fail the build today — additionalProperties:true is
+    // load-bearing for platform_extensions and seller-specific narrowings. But
+    // surfacing them helps fixture authors catch typos before merge.
+    process.exit(0);
+  }
+  console.log(`${RED}❌ ${fail} fixture(s) failed validation; ${pass} passed.${RESET}`);
+  process.exit(1);
+}
+
+main();
diff --git a/tests/canonical-format-conventions.test.cjs b/tests/canonical-format-conventions.test.cjs
new file mode 100644
index 0000000000..94364778fa
--- /dev/null
+++ b/tests/canonical-format-conventions.test.cjs
@@ -0,0 +1,248 @@
+#!/usr/bin/env node
+/**
+ * Canonical Formats convention lint
+ *
+ * Catches drift in format-declaration fixtures and schemas:
+ *
+ *   1. v1_format_ref.agent_url MUST follow the AAO-hosted convention:
+ *      - IAB-standard formats → https://creative.adcontextprotocol.org
+ *      - Platform-adopted     → platform's adopted agent_url (we don't validate which platforms have adopted)
+ *      - Platform-unadopted   → https://creative.adcontextprotocol.org/translated/<platform>
+ *      - Seller-bespoke       → seller's own agent_url (no constraint)
+ *
+ *      Disallowed: bare `<platform>.example` URIs for known-unadopted platforms (meta, google,
+ *      openai, tiktok, snap, pinterest). Use the community-mirror path instead so all sellers
+ *      converge on the same v1 namespace.
+ *
+ *   2. platform_extensions[].uri MUST follow the same rule (extensions ARE owned by the agent
+ *      identified by the URI base, so the same hosting convention applies).
+ *
+ *   3. canonical_formats_only and v1_format_ref are mutually exclusive (also enforced at schema
+ *      layer, doubled here so a test failure surfaces a clear narrative diagnostic).
+ *
+ *   4. format_kind: "custom" requires canonical_formats_only:true OR v1_format_ref (per
+ *      schema if/then; the test also surfaces the rule by name).
+ *
+ *   5. Slot-param consistency: when a format declaration's params include `cta_values` or
+ *      `*_max_chars` for a content type, the canonical's default slots OR the product's
+ *      override slots SHOULD declare a matching slot. Soft-warn (does not fail) until the
+ *      canonicals are updated to add default slots for cta and primary_text.
+ *
+ * Run: node tests/canonical-format-conventions.test.cjs
+ */
+
+const fs = require('fs');
+const path = require('path');
+
+const FIXTURES_DIR = path.resolve(__dirname, '../static/examples/products/canonical');
+const ADAGENTS_FIXTURES = path.resolve(__dirname, '../static/examples/adagents');
+const V1_CATALOG = path.resolve(__dirname, '../server/src/creative-agent/reference-formats.json');
+const RED = '\x1b[31m';
+const YELLOW = '\x1b[33m';
+const GREEN = '\x1b[32m';
+const RESET = '\x1b[0m';
+
+const AAO_CATALOG = 'creative.adcontextprotocol.org';
+const CANONICAL_DIR = path.resolve(__dirname, '../static/schemas/source/formats/canonical');
+const COMMUNITY_DIR = path.resolve(__dirname, '../static/examples/adagents/community');
+
+// Derive the unadopted-platform list from the community-mirror fixture filenames so
+// adding a new community/<platform>.json doesn't require also editing this test.
+// Plus a small seed list for platforms we haven't yet fixtured but know are unadopted.
+const UNADOPTED_PLATFORMS = (() => {
+  const fromFixtures = fs.existsSync(COMMUNITY_DIR)
+    ? fs.readdirSync(COMMUNITY_DIR).filter(f => f.endsWith('.json')).map(f => f.replace(/\.json$/, ''))
+    : [];
+  const seed = ['meta', 'google', 'openai', 'tiktok', 'snap', 'pinterest', 'youtube'];
+  return Array.from(new Set([...fromFixtures, ...seed]));
+})();
+
+// Load default slot ids per canonical format_kind from the canonical schemas.
+const CANONICAL_DEFAULT_SLOTS = (() => {
+  const out = {};
+  for (const f of fs.readdirSync(CANONICAL_DIR)) {
+    if (!f.endsWith('.json') || f === '_base.json') continue;
+    const kind = f.replace(/\.json$/, '');
+    try {
+      const s = JSON.parse(fs.readFileSync(path.join(CANONICAL_DIR, f), 'utf8'));
+      const def = s.properties && s.properties.slots && s.properties.slots.default;
+      out[kind] = new Set((def || []).map(slot => slot.asset_group_id));
+    } catch (_) { out[kind] = new Set(); }
+  }
+  return out;
+})();
+
+let errors = 0;
+let warnings = 0;
+
+function fail(file, msg) {
+  console.log(`  ${RED}✗${RESET} ${file}: ${msg}`);
+  errors++;
+}
+function warn(file, msg) {
+  console.log(`  ${YELLOW}⚠${RESET} ${file}: ${msg}`);
+  warnings++;
+}
+function pass(file, msg) {
+  console.log(`  ${GREEN}✓${RESET} ${file}${msg ? ': ' + msg : ''}`);
+}
+
+function isUnadoptedPlatformDotExample(url) {
+  const m = url.match(/^https:\/\/([a-z0-9-]+)\.example(\/|$)/);
+  if (!m) return false;
+  return UNADOPTED_PLATFORMS.includes(m[1]);
+}
+
+function checkAgentUrlConvention(url, ctx, file) {
+  if (isUnadoptedPlatformDotExample(url)) {
+    const platform = url.match(/^https:\/\/([a-z0-9-]+)\.example/)[1];
+    fail(file, `${ctx} uses unadopted-platform placeholder ${url} — use the community mirror at https://${AAO_CATALOG}/translated/${platform}/ instead`);
+    return false;
+  }
+  return true;
+}
+
+function checkDeclaration(decl, ctx, file) {
+  // Mutex: canonical_formats_only and v1_format_ref
+  if (decl.canonical_formats_only === true && decl.v1_format_ref) {
+    fail(file, `${ctx} has both canonical_formats_only:true AND v1_format_ref — mutually exclusive`);
+  }
+
+  // format_kind: custom requires canonical_formats_only:true OR v1_format_ref
+  if (decl.format_kind === 'custom') {
+    if (!decl.canonical_formats_only && !decl.v1_format_ref) {
+      fail(file, `${ctx} format_kind:custom requires canonical_formats_only:true OR v1_format_ref`);
+    }
+  }
+
+  // v1_format_ref is always an array — iterate
+  if (Array.isArray(decl.v1_format_ref)) {
+    decl.v1_format_ref.forEach((ref, i) => {
+      if (ref && ref.agent_url) {
+        checkAgentUrlConvention(ref.agent_url, `${ctx}.v1_format_ref[${i}].agent_url`, file);
+      }
+    });
+  } else if (decl.v1_format_ref) {
+    fail(file, `${ctx}.v1_format_ref must be an array (always-array shape); got ${typeof decl.v1_format_ref}`);
+  }
+
+  // platform_extensions[].uri convention
+  const exts = (decl.params && decl.params.platform_extensions) || [];
+  exts.forEach((ext, i) => {
+    if (ext.uri) checkAgentUrlConvention(ext.uri, `${ctx}.params.platform_extensions[${i}].uri`, file);
+  });
+
+  // Slot-param consistency. A declaration that doesn't override `slots[]` inherits the
+  // canonical's default slot set. Only warn when the declaration EITHER (a) overrides
+  // slots[] and removes the slot the param references, or (b) the canonical itself
+  // doesn't carry the slot as a default.
+  const params = decl.params || {};
+  const overrideSlots = params.slots;
+  const inheritedDefaults = CANONICAL_DEFAULT_SLOTS[decl.format_kind] || new Set();
+  const effectiveSlotIds = overrideSlots
+    ? new Set(overrideSlots.map(s => s.asset_group_id))
+    : inheritedDefaults;
+
+  if (params.cta_values && !effectiveSlotIds.has('cta')) {
+    warn(file, `${ctx} declares cta_values but effective slots[] has no 'cta' slot (canonical=${decl.format_kind})`);
+  }
+  if (params.primary_text_max_chars && !effectiveSlotIds.has('primary_text')) {
+    warn(file, `${ctx} declares primary_text_max_chars but effective slots[] has no 'primary_text' slot (canonical=${decl.format_kind})`);
+  }
+
+  // Size-mode mutex for canonicals that support sizes[] + responsive ranges (image, html5, display_tag).
+  // Exactly one of: (width AND height), sizes[], (min_width/max_width with optional min_height/max_height).
+  const SIZE_FLEX_CANONICALS = new Set(['image', 'html5', 'display_tag']);
+  if (SIZE_FLEX_CANONICALS.has(decl.format_kind)) {
+    const modes = [];
+    if (params.width !== undefined || params.height !== undefined) modes.push('fixed');
+    if (Array.isArray(params.sizes)) modes.push('sizes[]');
+    if (params.min_width !== undefined || params.max_width !== undefined ||
+        params.min_height !== undefined || params.max_height !== undefined) modes.push('min/max range');
+    if (modes.length > 1) {
+      fail(file, `${ctx} sets multiple size modes (${modes.join(' + ')}) — mutually exclusive; pick exactly one of (width,height) | sizes[] | min/max ranges`);
+    }
+    // fixed mode requires BOTH width and height
+    if (modes[0] === 'fixed' && (params.width === undefined || params.height === undefined)) {
+      fail(file, `${ctx} declares one of width/height but not both — fixed-size mode requires both`);
+    }
+  }
+}
+
+function walkProductFixtures() {
+  console.log(`\nProduct fixtures: ${FIXTURES_DIR}`);
+  for (const f of fs.readdirSync(FIXTURES_DIR)) {
+    if (!f.endsWith('.json')) continue;
+    const data = JSON.parse(fs.readFileSync(path.join(FIXTURES_DIR, f), 'utf8'));
+    const opts = data.format_options || [];
+    const errBefore = errors;
+    const warnBefore = warnings;
+    opts.forEach((opt, i) => checkDeclaration(opt, `format_options[${i}]`, f));
+    if (errors === errBefore && warnings === warnBefore) pass(f);
+  }
+}
+
+function walkV1Catalog() {
+  if (!fs.existsSync(V1_CATALOG)) return;
+  console.log(`\nv1 catalog: ${V1_CATALOG}`);
+  const data = JSON.parse(fs.readFileSync(V1_CATALOG, 'utf8'));
+  if (!Array.isArray(data)) return;
+  const errBefore = errors;
+  const warnBefore = warnings;
+  const f = path.relative(path.resolve(__dirname, '..'), V1_CATALOG);
+  for (const entry of data) {
+    if (!entry || typeof entry !== 'object') continue;
+    const can = entry.canonical;
+    const fid = entry.format_id?.id || '?';
+    if (can === undefined || can === null) continue;
+    if (typeof can === 'string') {
+      fail(f, `entry ${fid} uses bare-string canonical "${can}" — must be object form { kind: "${can}" } (canonical-projection-ref.json)`);
+    } else if (typeof can === 'object') {
+      if (!can.kind || typeof can.kind !== 'string') {
+        fail(f, `entry ${fid} canonical missing required "kind" field`);
+      }
+      // If slots_override is set, asset_source SHOULD also be explicit
+      if (can.slots_override && !can.asset_source) {
+        warn(f, `entry ${fid} declares slots_override without explicit asset_source — projection ambiguous, default buyer_uploaded may not match override`);
+      }
+    }
+  }
+  if (errors === errBefore && warnings === warnBefore) pass(f, `${data.length} entries`);
+}
+
+function walkAdagentsFixtures() {
+  if (!fs.existsSync(ADAGENTS_FIXTURES)) return;
+  console.log(`\nadagents.json fixtures: ${ADAGENTS_FIXTURES}`);
+  function walk(dir) {
+    for (const e of fs.readdirSync(dir, { withFileTypes: true })) {
+      const p = path.join(dir, e.name);
+      if (e.isDirectory()) { walk(p); continue; }
+      if (!e.name.endsWith('.json')) continue;
+      const data = JSON.parse(fs.readFileSync(p, 'utf8'));
+      const formats = data.formats || [];
+      const errBefore = errors;
+      const warnBefore = warnings;
+      formats.forEach((decl, i) => checkDeclaration(decl, `formats[${i}]`, path.relative(ADAGENTS_FIXTURES, p)));
+      if (errors === errBefore && warnings === warnBefore) pass(path.relative(ADAGENTS_FIXTURES, p));
+    }
+  }
+  walk(ADAGENTS_FIXTURES);
+}
+
+console.log('Canonical-Formats Convention Lint');
+console.log('==================================');
+
+walkProductFixtures();
+walkAdagentsFixtures();
+walkV1Catalog();
+
+console.log('');
+if (errors > 0) {
+  console.log(`${RED}✗ ${errors} convention violations${RESET}${warnings ? `, ${YELLOW}${warnings} warnings${RESET}` : ''}`);
+  process.exit(1);
+}
+if (warnings > 0) {
+  console.log(`${GREEN}✓ no violations${RESET}, ${YELLOW}${warnings} warnings${RESET} (canonicals need cta/primary_text default slots — see canonical-formats.mdx)`);
+  process.exit(0);
+}
+console.log(`${GREEN}✓ all conventions clean${RESET}`);
diff --git a/tests/canonical-negative-fixtures.test.cjs b/tests/canonical-negative-fixtures.test.cjs
new file mode 100644
index 0000000000..96b6a7f676
--- /dev/null
+++ b/tests/canonical-negative-fixtures.test.cjs
@@ -0,0 +1,429 @@
+#!/usr/bin/env node
+/**
+ * Canonical Formats Negative-fixture regression tests
+ *
+ * Validates that the canonical-formats schemas REJECT specific malformed inputs.
+ * Complements tests/canonical-fixture-validation.test.cjs (which validates that
+ * valid fixtures pass) with the inverse: that the schema's `allOf` if/then/else,
+ * oneOf discriminators, and required/not constraints actually reject the shapes
+ * they're meant to reject.
+ *
+ * Filed against PR #3307 review comment R3 (composability of top-level
+ * discriminator + allOf if/then/else + 12-branch oneOf on
+ * product-format-declaration.json). Adopters and SDK authors will rely on
+ * the schema's negative-side behavior; without these tests, regressions to
+ * silent-pass on malformed declarations would slip through.
+ *
+ * Run: npm run test:canonical-negative
+ */
+
+const Ajv = require('ajv').default;
+const addFormats = require('ajv-formats').default;
+const fs = require('fs');
+const path = require('path');
+
+const SCHEMAS_DIR = path.resolve(__dirname, '../static/schemas/source');
+const RED = '\x1b[31m';
+const GREEN = '\x1b[32m';
+const RESET = '\x1b[0m';
+
+function loadAllSchemas(ajv) {
+  function walk(dir) {
+    for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
+      const full = path.join(dir, entry.name);
+      if (entry.isDirectory()) {
+        walk(full);
+        continue;
+      }
+      if (!entry.name.endsWith('.json')) continue;
+      let schema;
+      try {
+        schema = JSON.parse(fs.readFileSync(full, 'utf8'));
+      } catch (e) {
+        console.error(`${RED}FAIL${RESET} parse error in ${full}: ${e.message}`);
+        process.exit(1);
+      }
+      if (!schema.$id) continue;
+      try {
+        ajv.addSchema(schema, schema.$id);
+      } catch (e) {
+        if (!/already exists/.test(e.message)) throw e;
+      }
+    }
+  }
+  walk(SCHEMAS_DIR);
+}
+
+const ajv = new Ajv({ allErrors: true, strict: false, discriminator: true });
+addFormats(ajv);
+ajv.addFormat('uri-template', true);
+loadAllSchemas(ajv);
+
+const SHA = 'sha256:0000000000000000000000000000000000000000000000000000000000000000';
+
+const NEGATIVE_CASES = {
+  '/schemas/core/product-format-declaration.json': [
+    {
+      label: 'format_kind=image rejects stray format_schema',
+      expected: false,
+      doc: {
+        format_kind: 'image',
+        params: { width: 300, height: 250 },
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+      },
+    },
+    {
+      label: 'format_kind=image rejects stray format_shape',
+      expected: false,
+      doc: {
+        format_kind: 'image',
+        params: { width: 300, height: 250 },
+        format_shape: 'multi_placement_takeover',
+      },
+    },
+    {
+      label: 'format_kind=custom rejects missing format_shape',
+      expected: false,
+      doc: {
+        format_kind: 'custom',
+        params: {},
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+      },
+    },
+    {
+      label: 'format_kind=custom rejects missing format_schema',
+      expected: false,
+      doc: {
+        format_kind: 'custom',
+        params: {},
+        format_shape: 'multi_placement_takeover',
+      },
+    },
+    {
+      label: 'bogus format_kind value rejected',
+      expected: false,
+      doc: { format_kind: 'banana', params: {} },
+    },
+    {
+      label: 'format_kind=custom complete (positive control)',
+      expected: true,
+      doc: {
+        format_kind: 'custom',
+        canonical_formats_only: true,
+        params: { foo: 'bar' },
+        format_shape: 'multi_placement_takeover',
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+      },
+    },
+    {
+      label: 'format_kind=custom rejects missing canonical_formats_only',
+      expected: false,
+      doc: {
+        format_kind: 'custom',
+        params: { foo: 'bar' },
+        format_shape: 'multi_placement_takeover',
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+      },
+    },
+    {
+      label: 'format_kind=custom rejects canonical_formats_only=false',
+      expected: false,
+      doc: {
+        format_kind: 'custom',
+        canonical_formats_only: false,
+        params: { foo: 'bar' },
+        format_shape: 'multi_placement_takeover',
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+      },
+    },
+    {
+      label: 'format_kind=image clean (positive control)',
+      expected: true,
+      doc: { format_kind: 'image', params: { width: 300, height: 250 } },
+    },
+    {
+      label: 'format_kind=image with canonical_formats_only=true accepted (Track-B canonical without v1 mapping)',
+      expected: true,
+      doc: { format_kind: 'image', canonical_formats_only: true, params: { width: 300, height: 250 } },
+    },
+    {
+      label: 'format_kind=image with canonical_formats_only=false accepted',
+      expected: true,
+      doc: { format_kind: 'image', canonical_formats_only: false, params: { width: 300, height: 250 } },
+    },
+    {
+      label: 'format_kind=image with v1_format_ref accepted (Track-A canonical linking to v1 named format)',
+      expected: true,
+      doc: {
+        format_kind: 'image',
+        v1_format_ref: [{ agent_url: 'https://nytimes.example', id: 'mrec_300x250' }],
+        params: { width: 300, height: 250 },
+      },
+    },
+    {
+      label: 'format_kind=custom with v1_format_ref accepted (custom format linked to a v1 named format)',
+      expected: true,
+      doc: {
+        format_kind: 'custom',
+        v1_format_ref: [{ agent_url: 'https://nytimes.example', id: 'homepage_takeover' }],
+        format_shape: 'multi_placement_takeover',
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+        params: { foo: 'bar' },
+      },
+    },
+    {
+      label: 'canonical_formats_only=true AND v1_format_ref rejected (mutually exclusive)',
+      expected: false,
+      doc: {
+        format_kind: 'image',
+        canonical_formats_only: true,
+        v1_format_ref: [{ agent_url: 'https://nytimes.example', id: 'mrec_300x250' }],
+        params: { width: 300, height: 250 },
+      },
+    },
+    {
+      label: 'format_kind=custom with neither canonical_formats_only:true nor v1_format_ref rejected',
+      expected: false,
+      doc: {
+        format_kind: 'custom',
+        format_shape: 'multi_placement_takeover',
+        format_schema: { uri: 'https://x.example/s', digest: SHA },
+        params: { foo: 'bar' },
+      },
+    },
+    {
+      label: 'v1_format_ref multi-entry array accepted (multi-size fan-out)',
+      expected: true,
+      doc: {
+        format_kind: 'image',
+        v1_format_ref: [
+          { agent_url: 'https://creative.adcontextprotocol.org/', id: 'display_300x250_image' },
+          { agent_url: 'https://creative.adcontextprotocol.org/', id: 'display_728x90_image' },
+          { agent_url: 'https://creative.adcontextprotocol.org/', id: 'display_970x250_image' },
+        ],
+        params: {
+          sizes: [
+            { width: 300, height: 250 },
+            { width: 728, height: 90 },
+            { width: 970, height: 250 },
+          ],
+        },
+      },
+    },
+  ],
+  '/schemas/formats/canonical/image.json': [
+    {
+      label: 'size-mode mutex: width+height AND sizes[] rejected',
+      expected: false,
+      doc: { width: 300, height: 250, sizes: [{ width: 728, height: 90 }] },
+    },
+    {
+      label: 'size-mode mutex: width+height AND min_width rejected',
+      expected: false,
+      doc: { width: 300, height: 250, min_width: 100 },
+    },
+    {
+      label: 'size-mode mutex: sizes[] AND min_height rejected',
+      expected: false,
+      doc: { sizes: [{ width: 300, height: 250 }], min_height: 200 },
+    },
+    {
+      label: 'fixed mode: width without height rejected',
+      expected: false,
+      doc: { width: 300 },
+    },
+    {
+      label: 'fixed mode: width+height alone accepted',
+      expected: true,
+      doc: { width: 300, height: 250 },
+    },
+    {
+      label: 'multi-size mode: sizes[] alone accepted',
+      expected: true,
+      doc: { sizes: [{ width: 300, height: 250 }, { width: 728, height: 90 }] },
+    },
+    {
+      label: 'responsive mode: min/max range alone accepted',
+      expected: true,
+      doc: { min_width: 300, max_width: 970, min_height: 50, max_height: 250 },
+    },
+    {
+      label: 'none mode: no size declared accepted (e.g., format-shape carrier)',
+      expected: true,
+      doc: {},
+    },
+  ],
+  '/schemas/core/assets/pixel-tracker-asset.json': [
+    {
+      label: 'minimal valid pixel_tracker (impression / img)',
+      expected: true,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'impression',
+        method: 'img',
+        url: 'https://measurement.example.com/imp?cb={CACHEBUSTER}',
+      },
+    },
+    {
+      label: 'valid pixel_tracker with method:js (impression jstracker)',
+      expected: true,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'impression',
+        method: 'js',
+        url: 'https://measurement.example.com/jstracker.js?cid={CREATIVE_ID}',
+      },
+    },
+    {
+      label: 'valid pixel_tracker for viewable_mrc_50',
+      expected: true,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'viewable_mrc_50',
+        method: 'img',
+        url: 'https://measurement.example.com/mrc50?cid={CREATIVE_ID}',
+      },
+    },
+    {
+      label: 'valid pixel_tracker for click',
+      expected: true,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'click',
+        method: 'img',
+        url: 'https://measurement.example.com/click?cid={CREATIVE_ID}',
+      },
+    },
+    {
+      label: 'valid pixel_tracker for audible_video_complete (IAB event 500)',
+      expected: true,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'audible_video_complete',
+        method: 'img',
+        url: 'https://measurement.example.com/audible_complete?cid={CREATIVE_ID}',
+      },
+    },
+    {
+      label: 'valid pixel_tracker for custom event with custom_event_name',
+      expected: true,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'custom',
+        custom_event_name: 'engagement_3s',
+        method: 'img',
+        url: 'https://measurement.example.com/engagement?cid={CREATIVE_ID}',
+      },
+    },
+    {
+      label: 'event=custom WITHOUT custom_event_name rejected',
+      expected: false,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'custom',
+        method: 'img',
+        url: 'https://measurement.example.com/custom_no_name',
+      },
+    },
+    {
+      label: 'event=impression WITH custom_event_name rejected (only valid when event=custom)',
+      expected: false,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'impression',
+        custom_event_name: 'should_not_be_here',
+        method: 'img',
+        url: 'https://measurement.example.com/imp',
+      },
+    },
+    {
+      label: 'invalid event enum value rejected',
+      expected: false,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'totally_made_up_event',
+        method: 'img',
+        url: 'https://measurement.example.com/x',
+      },
+    },
+    {
+      label: 'invalid method enum value rejected',
+      expected: false,
+      doc: {
+        asset_type: 'pixel_tracker',
+        event: 'impression',
+        method: 'server',
+        url: 'https://measurement.example.com/x',
+      },
+    },
+  ],
+  '/schemas/creative/validate-input-result.json': [
+    {
+      label: 'validated_pass rejects violations',
+      expected: false,
+      doc: {
+        target: { kind: 'canonical', id: 'image' },
+        result_kind: 'validated_pass',
+        violations: [{ rule: 'x', field: 'y' }],
+      },
+    },
+    {
+      label: 'unvalidatable_nondeterministic rejects violations',
+      expected: false,
+      doc: {
+        target: { kind: 'product', id: 'p1' },
+        result_kind: 'unvalidatable_nondeterministic',
+        violations: [{ rule: 'x', field: 'y' }],
+      },
+    },
+    {
+      label: 'old shape with `ok` boolean rejected (no `result_kind`)',
+      expected: false,
+      doc: { target: { kind: 'canonical', id: 'image' }, ok: true },
+    },
+    {
+      label: 'validated_fail with violations (positive control)',
+      expected: true,
+      doc: {
+        target: { kind: 'product', id: 'p1' },
+        result_kind: 'validated_fail',
+        violations: [
+          { rule: 'duration_ms_range', expected: '3000-90000', predicted: 95000, field: 'assets.video_main.duration_ms' },
+        ],
+      },
+    },
+  ],
+};
+
+let pass = 0;
+let fail = 0;
+
+for (const [schemaId, cases] of Object.entries(NEGATIVE_CASES)) {
+  const validate = ajv.getSchema(schemaId);
+  if (!validate) {
+    console.error(`${RED}FAIL${RESET} schema ${schemaId} not loaded`);
+    fail++;
+    continue;
+  }
+  console.log(`\n${schemaId}`);
+  for (const c of cases) {
+    const got = validate(c.doc);
+    if (got === c.expected) {
+      console.log(`  ${GREEN}✓${RESET} ${c.label}`);
+      pass++;
+    } else {
+      console.log(`  ${RED}✗${RESET} ${c.label} — got ${got}, want ${c.expected}`);
+      if (validate.errors) {
+        console.log(`    errors: ${JSON.stringify(validate.errors.slice(0, 2))}`);
+      }
+      fail++;
+    }
+  }
+}
+
+console.log(`\n${pass} passed, ${fail} failed`);
+if (fail > 0) {
+  console.log(`${RED}❌ ${fail} negative-fixture regression(s)${RESET}`);
+  process.exit(1);
+}
+console.log(`${GREEN}✅ All ${pass} negative fixtures behaved as expected.${RESET}`);
diff --git a/tests/schema-validation.test.cjs b/tests/schema-validation.test.cjs
index fd80c951d7..fc759d98cf 100644
--- a/tests/schema-validation.test.cjs
+++ b/tests/schema-validation.test.cjs
@@ -279,10 +279,12 @@ async function runTests() {
   await test('Core schemas have appropriate required fields', () => {
     const coreSchemas = schemas.filter(([path]) => path.includes('/core/'));
     const requiredFieldChecks = {
-      'product.json': ['product_id', 'name', 'description', 'format_ids', 'delivery_type'],
+      // product.json: format_ids OR format_options is required (v1 OR v2 path) — checked separately below
+      // creative-asset.json: format_id OR format_kind is required (v1 OR v2 path) — checked separately below
+      'product.json': ['product_id', 'name', 'description', 'delivery_type'],
       'media-buy.json': ['media_buy_id', 'status', 'total_budget', 'packages'],
       'package.json': ['package_id'],
-      'creative-asset.json': ['creative_id', 'name', 'format_id', 'assets'],
+      'creative-asset.json': ['creative_id', 'name', 'assets'],
       'error.json': ['code', 'message']
     };
 
@@ -299,6 +301,39 @@ async function runTests() {
         }
       }
     }
+
+    // product.json: assert v1 (format_ids) OR v2 (format_options) is required via anyOf — at-least-one,
+    // BOTH allowed during the migration window (per RFC #3305 amendment #3765). The previous oneOf-with-not
+    // shape required exactly one and forbade dual emission, which broke the seller migration story.
+    const productEntry = coreSchemas.find(([p]) => path.basename(p) === 'product.json');
+    if (productEntry) {
+      const [, productSchema] = productEntry;
+      const anyOf = productSchema.anyOf || [];
+      const hasV1Branch = anyOf.some((branch) => (branch.required || []).includes('format_ids'));
+      const hasV2Branch = anyOf.some((branch) => (branch.required || []).includes('format_options'));
+      if (!hasV1Branch || !hasV2Branch) {
+        return `product.json: must have an anyOf with v1 branch (required: ["format_ids"]) and v2 branch (required: ["format_options"]); found v1=${hasV1Branch}, v2=${hasV2Branch}`;
+      }
+      // No-not invariant: branches MUST NOT carry `not` clauses excluding the other branch — that would
+      // be the old oneOf behavior. anyOf with no negative constraints lets dual-emission products validate.
+      const hasForbiddenNotClause = anyOf.some((branch) => branch.not && branch.not.required);
+      if (hasForbiddenNotClause) {
+        return `product.json: anyOf branches must not carry 'not: required' clauses — dual emission of format_ids + format_options is legal during migration. See #3765.`;
+      }
+    }
+
+    // creative-asset.json: assert v1 (format_id) OR v2 (format_kind) is required via oneOf
+    const creativeAssetEntry = coreSchemas.find(([p]) => path.basename(p) === 'creative-asset.json');
+    if (creativeAssetEntry) {
+      const [, creativeAssetSchema] = creativeAssetEntry;
+      const oneOf = creativeAssetSchema.oneOf || [];
+      const hasV1Branch = oneOf.some((branch) => (branch.required || []).includes('format_id'));
+      const hasV2Branch = oneOf.some((branch) => (branch.required || []).includes('format_kind'));
+      if (!hasV1Branch || !hasV2Branch) {
+        return `creative-asset.json: must have a oneOf with v1 branch (required: ["format_id"]) and v2 branch (required: ["format_kind"]); found v1=${hasV1Branch}, v2=${hasV2Branch}`;
+      }
+    }
+
     return true;
   });