diff --git a/.jules/bolt.md b/.jules/bolt.md
index e7066a3ac..a86b7aafd 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -40,3 +40,6 @@
 ## 2024-11-23 - Memoize File-Based Subprocess Queries in Embedded Python Scripts
 **Learning:** Found an N+1 subprocess bottleneck in `scripts/ci/opencode_review_approve_gate.sh` where `changed_new_lines` invoked `git diff` for every finding, even when multiple findings pointed to the same file. Repeatedly shelling out inside loops is a severe performance anti-pattern.
 **Action:** When validating multiple findings against the same file, decorate the inspection function with `@functools.cache` and ensure the return value is immutable (e.g., `frozenset` instead of `set`) to avoid redundant subprocess calls.
+## 2026-07-09 - Avoid N+1 API blocking in SBOM aggregator
+**Learning:** The `collect_inventories` function in `scripts/ci/sbom_inventory_aggregator.py` was fetching SBOMs from the GitHub dependency graph synchronously for every repository in the organization. For large organizations (up to 500 repos), this N+1 network/CLI bottleneck significantly stalled the aggregation workflow.
+**Action:** Use `concurrent.futures.ThreadPoolExecutor` to fetch SBOMs concurrently when multiple repositories are provided, bounded by a `max_workers` limit (e.g., 10) to avoid overwhelming the CLI/API, while preserving the fast serial path for single-item inputs.
diff --git a/scripts/ci/sbom_inventory_aggregator.py b/scripts/ci/sbom_inventory_aggregator.py
index 1037c1e0f..3a55cffc1 100644
--- a/scripts/ci/sbom_inventory_aggregator.py
+++ b/scripts/ci/sbom_inventory_aggregator.py
@@ -22,6 +22,7 @@
 from __future__ import annotations
 
 import argparse
+import concurrent.futures
 import json
 import subprocess
 import sys
@@ -29,6 +30,8 @@
 from pathlib import Path
 from typing import Any, Iterable, Sequence
 
+SBOM_FETCH_WORKERS = 10
+
 # Licenses that violate the commercial-license-only policy. Matched as
 # case-insensitive substrings against the normalized SPDX license expression so
 # variants like "LGPL-3.0-or-later" or "AGPL-3.0-only" are all caught.
@@ -277,7 +280,12 @@ def render_inventory_markdown(inventory: dict[str, Any], *, generated_at: str) -
 
     lines.extend(["", "## Flagged components (policy violations)", ""])
     if inventory["flagged_licenses"]:
-        lines.extend(["| Repository | Component | Version | License |", "| --- | --- | --- | --- |"])
+        lines.extend(
+            [
+                "| Repository | Component | Version | License |",
+                "| --- | --- | --- | --- |",
+            ]
+        )
         for item in inventory["flagged_licenses"]:
             lines.append(
                 f"| {item['repo']} | {item['name']} | {item['version'] or '—'} | {item['license']} |"
@@ -297,7 +305,9 @@ def render_inventory_markdown(inventory: dict[str, Any], *, generated_at: str) -
             lines.append("No components reported.")
             lines.append("")
             continue
-        lines.extend(["| Component | Version | License | Flagged |", "| --- | --- | --- | --- |"])
+        lines.extend(
+            ["| Component | Version | License | Flagged |", "| --- | --- | --- | --- |"]
+        )
         for component in repo["components"]:
             flag = "yes" if component["flagged"] else "no"
             lines.append(
@@ -346,15 +356,25 @@ def fetch_repo_sbom(repo: str) -> RepoInventory:  # pragma: no cover - network
         raw = _run(["gh", "api", f"/repos/{repo}/dependency-graph/sbom"])
     except subprocess.CalledProcessError as exc:
         detail = (exc.stderr or "").strip().splitlines()
-        return RepoInventory(repo=repo, error=detail[-1] if detail else "sbom unavailable")
+        return RepoInventory(
+            repo=repo, error=detail[-1] if detail else "sbom unavailable"
+        )
     payload = json.loads(raw or "{}")
     document = payload.get("sbom", payload)
     return RepoInventory(repo=repo, components=parse_sbom(document))
 
 
-def collect_inventories(repos: Sequence[str]) -> list[RepoInventory]:  # pragma: no cover - network
+def collect_inventories(
+    repos: Sequence[str],
+) -> list[RepoInventory]:  # pragma: no cover - network
     """Fetch every repository's SBOM into per-repo inventories."""
-    return [fetch_repo_sbom(repo) for repo in repos]
+    if len(repos) <= 1:
+        return [fetch_repo_sbom(repo) for repo in repos]
+
+    max_workers = min(SBOM_FETCH_WORKERS, len(repos))
+    with concurrent.futures.ThreadPoolExecutor(max_workers=max_workers) as executor:
+        # Keep original order by using map and converting to list
+        return list(executor.map(fetch_repo_sbom, repos))
 
 
 def self_test() -> None:
@@ -364,8 +384,18 @@ def self_test() -> None:
         "SPDXID": "SPDXRef-DOCUMENT",
         "packages": [
             {"SPDXID": "SPDXRef-root", "name": "self", "versionInfo": "1.0"},
-            {"SPDXID": "SPDXRef-a", "name": "left-pad", "versionInfo": "1.3.0", "licenseConcluded": "MIT"},
-            {"SPDXID": "SPDXRef-b", "name": "readline", "versionInfo": "8.2", "licenseDeclared": "GPL-3.0-or-later"},
+            {
+                "SPDXID": "SPDXRef-a",
+                "name": "left-pad",
+                "versionInfo": "1.3.0",
+                "licenseConcluded": "MIT",
+            },
+            {
+                "SPDXID": "SPDXRef-b",
+                "name": "readline",
+                "versionInfo": "8.2",
+                "licenseDeclared": "GPL-3.0-or-later",
+            },
         ],
         "relationships": [
             {"relationshipType": "DESCRIBES", "relatedSpdxElement": "SPDXRef-root"},
@@ -385,8 +415,12 @@ def self_test() -> None:
 
 def build_arg_parser() -> argparse.ArgumentParser:
     """Build the CLI argument parser for the aggregator."""
-    parser = argparse.ArgumentParser(description="Aggregate org SBOMs into a central inventory.")
-    parser.add_argument("--org", default="ContextualWisdomLab", help="GitHub organization login")
+    parser = argparse.ArgumentParser(
+        description="Aggregate org SBOMs into a central inventory."
+    )
+    parser.add_argument(
+        "--org", default="ContextualWisdomLab", help="GitHub organization login"
+    )
     parser.add_argument(
         "--output-dir",
         default="docs/sbom",
@@ -399,8 +433,12 @@ def build_arg_parser() -> argparse.ArgumentParser:
         default=None,
         help="Explicit repo (owner/name); repeatable. Overrides org discovery.",
     )
-    parser.add_argument("--generated-at", default="", help="Timestamp label for the markdown header")
-    parser.add_argument("--self-test", action="store_true", help="Run in-process assertions and exit")
+    parser.add_argument(
+        "--generated-at", default="", help="Timestamp label for the markdown header"
+    )
+    parser.add_argument(
+        "--self-test", action="store_true", help="Run in-process assertions and exit"
+    )
     return parser