Proper use of HTTP return codes
From Logic Wiki
Return the correct HTTP status codes to represent different outcomes:
- 200 OK: Successful GET or PUT request.
- 201 Created: Successful POST request.
- 204 No Content: Successful DELETE request.
- 400 Bad Request: Client-side input validation failure.
- 401 Unauthorized: Authentication is required but missing or invalid.
- 404 Not Found: Requested resource is not available.
- 500 Internal Server Error: Unexpected error occurred.
