feat(agent): Gemini/Anthropic を Vertex AI（SA→ADC）経由に移行（ADR-0015）

[yusuke0610]

Summary

職務経歴書（PII）を扱う本番環境として、Gemini Developer API の無料枠（学習リスク）を廃止。Gemini と Anthropic を Vertex AI（Cloud Run の SA → ADC）に切り替え、シークレットを OpenAI キー 1 本に削減。

• Google Gemini: asia-northeast1（Tokyo）で Vertex 経由に
• Anthropic Claude: asia-southeast1（Singapore）で Vertex 経由に（Tokyo 未提供のため最寄り）
• OpenAI GPT: API キー継続（GCP に無い）

技術変更

• google_client.py: genai.Client(vertexai=True, project, location) 化
• anthropic_client.py: AsyncAnthropicVertex(project_id, region) 化
• model_catalog.py: Haiku を Vertex 版 ID（claude-haiku-4-5@20251001）に統一
• 環境変数：ANTHROPIC_API_KEY / GOOGLE_API_KEY 廃止、VERTEX_LOCATION / VERTEX_ANTHROPIC_LOCATION 追加
• requirements.txt: anthropic[vertex] で ADC 対応
• infra(cloud_run): 注入を OpenAI キーのみに絞り込み（secret コンテナ削除は別 PR）

検証

• make ci (lint + test): pass ✅
• Backend テスト: 582 green ✅
• OpenAPI drift: なし ✅
• infra fmt-check: pass ✅

トレードオフ

• regional endpoint 課金: Claude の Singapore regional は global 比 +10% プレミアム（PII 保護優先）
• ローカル・CI: LLM_LOCAL_OLLAMA=1 で Vertex を避ける（ADC 不要）。実 Vertex をローカルで試す場合のみ gcloud auth application-default login
• 要・実デプロイ確認: asia-southeast1 での Claude 提供と model id は実デプロイで確認（pytest/CI smoke では Vertex 実呼び出し未検証）

関連

• ADR-0015: Vertex AI / SA→ADC / リージョン戦略 / トレードオフを新規に起票
• ADR-0013（マルチプロバイダ）の認証部分を更新

🤖 Generated with Claude Code

Summary by CodeRabbit

• Chores
  • Switched Gemini and Claude/Anthropic LLM access to Vertex AI using application default credentials (no API keys).
  • Updated configuration: removed ANTHROPIC_API_KEY / GOOGLE_API_KEY; added VERTEX_LOCATION and VERTEX_ANTHROPIC_LOCATION (with defaults).
  • Updated Claude Haiku to the versioned Vertex-compatible model ID.
• Documentation
  • Added ADR-0015 and updated LLM environment variable docs.
• Tests
  • Updated LLM client and billing expectations for Vertex and the versioned model ID.
• Infra
  • Updated Cloud Run secret/env injection behavior and Cloudflare CNAME resource/TTL handling.
  • Refreshed Terraform/OpenTofu provider lock files.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 9d871ef7-3a0f-4213-977a-80ae315200fc

📥 Commits

Reviewing files that changed from the base of the PR and between 10f5fae and 84e503f.

📒 Files selected for processing (3)

• docs/adr/0015-vertex-ai-for-gemini-anthropic.md
• infra/modules/cloud_run/variables.tf
• infra/modules/cloudflare/main.tf

✅ Files skipped from review due to trivial changes (1)

• docs/adr/0015-vertex-ai-for-gemini-anthropic.md

🚧 Files skipped from review as they are similar to previous changes (2)

• infra/modules/cloud_run/variables.tf
• infra/modules/cloudflare/main.tf

---

📝 Walkthrough

Walkthrough

Migrates Gemini and Anthropic LLM clients to Vertex AI using GCP project and region configuration, updates related docs, tests, and runtime wiring, versions the Haiku model ID, and refreshes Terraform provider locks plus Cloudflare resource naming.

Changes

Vertex AI Migration

Layer / File(s)	Summary
Env and settings contract backend/app/core/env_keys.py, backend/app/core/settings.py, backend/requirements.txt	Removes Anthropic/Google API-key env access, adds GCP project and Vertex location getters, and enables the Anthropic Vertex extra dependency.
GCP project validation backend/app/services/agent/llm/base.py	Adds require_gcp_project for empty-project validation.
Vertex client initialization backend/app/services/agent/llm/anthropic_client.py, backend/app/services/agent/llm/google_client.py	Switches both LLM clients to Vertex AI initialization with GCP project and region settings.
Haiku model ID update backend/app/services/agent/model_catalog.py	Pins the Haiku model ID to claude-haiku-4-5@20251001.
Cloud Run and local env wiring infra/modules/cloud_run/variables.tf, infra/modules/cloud_run/main.tf, docker-compose.yml	Adds Vertex region inputs, injects Vertex location env vars, and changes secret injection to match the new provider setup.
Docs and test updates docs/adr/0015-vertex-ai-for-gemini-anthropic.md, docs/api.md, backend/tests/test_llm_clients.py, backend/tests/test_billing.py	Documents the Vertex migration and updates client and billing tests for the new auth and model ID behavior.

Infrastructure Maintenance

Layer / File(s)	Summary
Terraform provider repins infra/environments/dev/.terraform.lock.hcl, infra/environments/prod/.terraform.lock.hcl, infra/environments/stg/.terraform.lock.hcl	Updates Cloudflare, Google, and Turso provider versions, constraints, and hashes across environments.
Cloudflare DNS resource rename infra/modules/cloudflare/main.tf	Renames the Cloudflare DNS record resource and adds a moved state block.
AGENTS simplification AGENTS.md	Replaces the detailed guide with a single pointer to .claude/CLAUDE.md.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• yusuke0610/devforge#331: Shares the same LLM configuration surface in env_keys.py, settings.py, and the Google/Anthropic client wiring.
• yusuke0610/devforge#321: Touches the same LLM env and Anthropic client areas that this PR rewires for Vertex AI.
• yusuke0610/devforge#332: Modifies the same anthropic_client.py and shared LLM helper path used here.

Suggested labels

feature

Poem

🐇 Hop, hop, the keys are gone,
Vertex regions shine at dawn.
GCP and ADC align,
Claude and Gemini work just fine.
One little rabbit gives a cheer,
“Keyless clouds are now right here!”

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	Gemini/Anthropic の Vertex AI への移行と ADR-0015 を端的に示しており、変更内容の मुख्य点と一致しています。
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/vertex-ai-llm-providers

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@docker-compose.yml`:
- Around line 42-43: The VERTEX_LOCATION and VERTEX_ANTHROPIC_LOCATION
environment variables in docker-compose.yml are using bare variable substitution
syntax without default values, which causes unset variables to become empty
strings instead of allowing the backend to apply its own fallback defaults.
Modify both variable references to include default values using the Docker
Compose syntax of ${VARIABLE_NAME:-default_value}, ensuring that when these
environment variables are not set, appropriate default values are used instead
of empty strings to prevent Vertex clients from being initialized with blank
locations.

In `@infra/modules/cloud_run/main.tf`:
- Around line 12-16: The deprecated `anthropic-api-key` and `google-api-key`
entries are still present in `local.secret_names`, which causes unnecessary IAM
permissions to be granted to the Cloud Run service account even though these
secrets are no longer used after the Vertex AI migration. Remove both the
`anthropic-api-key` and `google-api-key` strings from the `local.secret_names`
list to follow least privilege IAM principles and ensure the Cloud Run service
account only has access to the secrets it actually needs.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: e7aec2cd-6897-4d2b-ae41-b8e4c8f49a52

📥 Commits

Reviewing files that changed from the base of the PR and between 9fc6f10 and 609eaf5.

📒 Files selected for processing (14)

• backend/app/core/env_keys.py
• backend/app/core/settings.py
• backend/app/services/agent/llm/anthropic_client.py
• backend/app/services/agent/llm/base.py
• backend/app/services/agent/llm/google_client.py
• backend/app/services/agent/model_catalog.py
• backend/requirements.txt
• backend/tests/test_billing.py
• backend/tests/test_llm_clients.py
• docker-compose.yml
• docs/adr/0015-vertex-ai-for-gemini-anthropic.md
• docs/api.md
• infra/modules/cloud_run/main.tf
• infra/modules/cloud_run/variables.tf

[yusuke0610]

@coderabbitai RVして

[coderabbitai]

@yusuke0610 了解です！PR #401 のレビューを開始します 🐇

✅ Action performed

Full review finished.

[coderabbitai]

Actionable comments posted: 3

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@docs/adr/0015-vertex-ai-for-gemini-anthropic.md`:
- Line 47: The ADR statement at line 47 describing the deprecated secret
retention strategy is inconsistent with the current infrastructure
implementation in infra/modules/cloud_run/main.tf, which already removes
anthropic-api-key and google-api-key from the secret_names list. Update the ADR
documentation to reflect the actual current state where these secrets are
already being excluded and will be deleted on the next terraform apply, rather
than stating they will be retained for deletion in a separate PR.

In `@infra/modules/cloud_run/variables.tf`:
- Around line 67-77: Add validation blocks to both the vertex_location and
vertex_anthropic_location variables to ensure they only accept non-empty string
values. Use a Terraform validation condition that checks the string length is
greater than zero, with an error message indicating that these variables cannot
be empty, as empty values would prevent proper Vertex AI client initialization
in Cloud Run.

In `@infra/modules/cloudflare/main.tf`:
- Around line 19-29: Add a moved block to the infra/modules/cloudflare/main.tf
file to handle the resource migration from cloudflare_record.app to
cloudflare_dns_record.app. The moved block should map the old resource state
(cloudflare_record.app) to the new resource type (cloudflare_dns_record.app) to
prevent Terraform from destroying and recreating the DNS record during the
upgrade to Cloudflare provider v5. Place this moved block in the same file where
the cloudflare_dns_record.app resource is defined.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 2956ce6c-ea41-41c8-ac80-792f0dae66ea

📥 Commits

Reviewing files that changed from the base of the PR and between 9fc6f10 and 10f5fae.

📒 Files selected for processing (19)

• AGENTS.md
• backend/app/core/env_keys.py
• backend/app/core/settings.py
• backend/app/services/agent/llm/anthropic_client.py
• backend/app/services/agent/llm/base.py
• backend/app/services/agent/llm/google_client.py
• backend/app/services/agent/model_catalog.py
• backend/requirements.txt
• backend/tests/test_billing.py
• backend/tests/test_llm_clients.py
• docker-compose.yml
• docs/adr/0015-vertex-ai-for-gemini-anthropic.md
• docs/api.md
• infra/environments/dev/.terraform.lock.hcl
• infra/environments/prod/.terraform.lock.hcl
• infra/environments/stg/.terraform.lock.hcl
• infra/modules/cloud_run/main.tf
• infra/modules/cloud_run/variables.tf
• infra/modules/cloudflare/main.tf