Context
FastAPI already returns 422 Unprocessable Entity by default for Pydantic validation failures, which is the correct and semantically precise behavior. This ticket exists to make that choice explicit and intentional rather than an implicit framework default.
Proposed Solution
- Document the intentional use of
422 vs 400 in route docstrings (validation failure → 422, malformed request → 400)
- Verify all manually raised
HTTPException instances use the correct code for their category
- Ensure OpenAPI docs explicitly declare
422 responses on the relevant endpoints
Acceptance Criteria
References
Context
FastAPI already returns
422 Unprocessable Entityby default for Pydantic validation failures, which is the correct and semantically precise behavior. This ticket exists to make that choice explicit and intentional rather than an implicit framework default.Proposed Solution
422vs400in route docstrings (validation failure →422, malformed request →400)HTTPExceptioninstances use the correct code for their category422responses on the relevant endpointsAcceptance Criteria
422for validation failures and400for malformed requestsHTTPExceptioninstances verified against the400vs422distinctionresponses={422: {"description": "Unprocessable Entity"}}where applicableCHANGELOG.mdupdatedReferences