Krow-workspace/docs/MILESTONES/M4/planning/m4-api-catalog.md

M4 API Catalog (Core Only)

Status: Active
Date: 2026-02-24
Owner: Technical Lead
Environment: dev

Frontend source of truth

Use this file and docs/MILESTONES/M4/planning/m4-core-api-frontend-guide.md for core endpoint consumption.

Related next-slice contract

Verification pipeline design (attire, government ID, certification):

• docs/MILESTONES/M4/planning/m4-verification-architecture-contract.md

1) Scope and purpose

This catalog defines the currently implemented core backend contract for M4.

2) Global API rules

1. Route group in scope: /core/*.
2. Compatibility aliases in scope:

• POST /uploadFile -> POST /core/upload-file
• POST /createSignedUrl -> POST /core/create-signed-url
• POST /invokeLLM -> POST /core/invoke-llm

3. Auth model:

• GET /health is public in dev
• all other routes require Authorization: Bearer <firebase-id-token>

4. Standard error envelope:

{
  "code": "STRING_CODE",
  "message": "Human readable message",
  "details": {},
  "requestId": "optional-request-id"
}

5. Response header:

• X-Request-Id

3) Core routes

3.1 Upload file

1. Method and route: POST /core/upload-file
2. Request format: multipart/form-data
3. Fields:

• file (required)
• visibility (public or private, optional)
• category (optional)

4. Accepted types:

• application/pdf
• image/jpeg
• image/jpg
• image/png

5. Max size: 10 MB (default)
6. Behavior: real upload to Cloud Storage.
7. Success 200:

{
  "fileUri": "gs://krow-workforce-dev-private/uploads/<uid>/...",
  "contentType": "application/pdf",
  "size": 12345,
  "bucket": "krow-workforce-dev-private",
  "path": "uploads/<uid>/...",
  "requestId": "uuid"
}

8. Errors:

• UNAUTHENTICATED
• INVALID_FILE_TYPE
• FILE_TOO_LARGE

3.2 Create signed URL

1. Method and route: POST /core/create-signed-url
2. Request:

{
  "fileUri": "gs://krow-workforce-dev-private/uploads/<uid>/file.pdf",
  "expiresInSeconds": 300
}

3. Security checks:

• bucket must be allowed
• path must be owned by caller (uploads/<caller_uid>/...)
• object must exist
• expiresInSeconds <= 900

4. Success 200:

{
  "signedUrl": "https://storage.googleapis.com/...",
  "expiresAt": "2026-02-24T15:22:28.105Z",
  "requestId": "uuid"
}

5. Errors:

• VALIDATION_ERROR
• FORBIDDEN
• NOT_FOUND

3.3 Invoke model

1. Method and route: POST /core/invoke-llm
2. Request:

{
  "prompt": "...",
  "responseJsonSchema": {},
  "fileUrls": []
}

3. Behavior:

• real Vertex AI call
• model default: gemini-2.0-flash-001
• timeout default: 20 seconds

4. Rate limit:

• 20 requests/minute per user (default)
• when exceeded: 429 RATE_LIMITED and Retry-After header

5. Success 200:

{
  "result": {},
  "model": "gemini-2.0-flash-001",
  "latencyMs": 367,
  "requestId": "uuid"
}

6. Errors:

• UNAUTHENTICATED
• VALIDATION_ERROR
• MODEL_TIMEOUT
• MODEL_FAILED
• RATE_LIMITED

3.4 Health

1. Method and route: GET /health
2. Success 200:

{
  "ok": true,
  "service": "krow-core-api",
  "version": "dev",
  "requestId": "uuid"
}

4) Locked defaults

1. Validation library: zod.
2. Validation schema location: backend/core-api/src/contracts/.
3. Buckets:

• krow-workforce-dev-public
• krow-workforce-dev-private

4. Model provider: Vertex AI Gemini.
5. Max signed URL expiry: 900 seconds.
6. LLM timeout: 20000 ms.
7. LLM rate limit: 20 requests/minute/user.