Status Codes for CRUD Operations
Create (POST)
- 201 Created — Resource created successfully. Include
Location header with new resource URL.
- 202 Accepted — Request accepted for async processing.
- 409 Conflict — Resource already exists or state conflict.
Read (GET)
- 200 OK — Resource found and returned.
- 404 Not Found — Resource doesn't exist.
- 304 Not Modified — Use cached version (conditional request).
Update (PUT/PATCH)
- 200 OK — Updated and returning the resource.
- 204 No Content — Updated, no body returned.
- 409 Conflict — Concurrent modification conflict.
- 422 Unprocessable Entity — Validation failed.
Delete (DELETE)
- 204 No Content — Deleted successfully.
- 202 Accepted — Deletion queued for processing.
- 404 Not Found — Resource already gone.
Error Codes to Know
- 400 Bad Request — Malformed request syntax, missing fields
- 401 Unauthorized — No valid credentials provided
- 403 Forbidden — Credentials valid but insufficient permissions
- 404 Not Found — Resource doesn't exist
- 422 Unprocessable Entity — Semantic errors (invalid email format)
- 429 Too Many Requests — Rate limit exceeded
Anti-Patterns
- Don't return 200 for errors — Use proper 4xx/5xx codes
- Don't use 500 for validation errors — That's a client error (4xx)
- Don't invent custom status codes — Use standard ones with error detail in the body