Status codes communicate the outcome of a request.

Success codes

• 200 OK — request succeeded.
• 201 Created — resource created.
• 202 Accepted — accepted for processing, which may not be complete.
• 204 No Content — succeeded without a response body. Client and server errors
• 400 Bad Request — malformed or invalid request.
• 401 Unauthorized — authentication is missing or unsuccessful.
• 403 Forbidden — request is refused, often due to permissions.
• 404 Not Found — resource not found.
• 409 Conflict — conflict with current state.
• 422 Unprocessable Content — semantically invalid content.
• 429 Too Many Requests — rate limit exceeded.
• 500 Internal Server Error — unexpected server failure.
• 502 Bad Gateway — invalid upstream response.
• 503 Service Unavailable — temporarily unavailable.
• 504 Gateway Timeout — upstream did not respond in time