What HTTP status codes are appropriate for common address API errors?

What HTTP status codes are appropriate for common address API errors?

• A. 400 Bad Request for validation failures, 401/403 for auth, 404 Not Found, 409 Conflict for duplicates, 422 Unprocessable Entity for semantic issues, 429 Too Many Requests
• B. 200 OK for all errors
• C. 500 Internal Server Error for all client errors
• D. 301 Moved Permanently for validation

Answer: (A)

Choosing the right HTTP status codes communicates the exact nature of errors to API clients, so they can respond appropriately. For common address API errors, map client-side problems to 4xx codes: use 400 Bad Request when the input fails basic validation, since the request data isn’t acceptable as-is. If authentication is missing or invalid, 401 Unauthorized signals the need to authenticate, while 403 Forbidden indicates the user is authenticated but not allowed to perform the action. When a requested resource can’t be found, 404 Not Found is the clear signal. If a request would create a duplicate or violate a constraint, 409 Conflict communicates the conflict. For semantic issues where the data is syntactically valid but semantically wrong, 422 Unprocessable Entity fits. When a client is making requests too frequently, 429 Too Many Requests expresses rate limiting. Server-side failures belong with 5xx codes like 500 Internal Server Error. Other options mislabel errors: using 200 OK for all errors hides problems, 301 Moved Permanently is a redirect and not appropriate for validation, and applying a 500 Internal Server Error to client errors wrongly signals a server issue.

Choosing the right HTTP status codes communicates the exact nature of errors to API clients, so they can respond appropriately. For common address API errors, map client-side problems to 4xx codes: use 400 Bad Request when the input fails basic validation, since the request data isn’t acceptable as-is. If authentication is missing or invalid, 401 Unauthorized signals the need to authenticate, while 403 Forbidden indicates the user is authenticated but not allowed to perform the action. When a requested resource can’t be found, 404 Not Found is the clear signal. If a request would create a duplicate or violate a constraint, 409 Conflict communicates the conflict. For semantic issues where the data is syntactically valid but semantically wrong, 422 Unprocessable Entity fits. When a client is making requests too frequently, 429 Too Many Requests expresses rate limiting. Server-side failures belong with 5xx codes like 500 Internal Server Error.

Other options mislabel errors: using 200 OK for all errors hides problems, 301 Moved Permanently is a redirect and not appropriate for validation, and applying a 500 Internal Server Error to client errors wrongly signals a server issue.