JSON 응답에 상태 코드 설정하기

Every HTTP response carries a status code that signals success or failure. Your JSON body explains the details, but the code sets the tone first. 🚦

When you return jsonify alone, Flask sends 200 OK. That is perfect for a successful read, but other actions deserve their own code.

To choose a code, return a tuple of the JSON response and the number. Flask reads the second element as the HTTP status to send.

When a request creates a new record, reply with 201 Created. It tells the client the resource now exists, which 200 alone would not convey.

If the requested item does not exist, return a JSON body with 404. The client learns the resource is missing, not that the server broke.

When a client sends invalid data, answer with 400 Bad Request. Pair it with a JSON message that explains exactly what went wrong.

Codes in the 2xx range mean success. 200 reads, 201 creates, and 204 signals success with no body to send back.

Codes in the 4xx range blame the client. 400 means bad input, 401 means unauthenticated, and 403 means forbidden.

Codes in the 5xx range blame the server. A 500 means your code raised an unhandled error while processing an otherwise valid request.

You can extend the tuple to three parts: body, status, and a headers dict. That lets you attach extra metadata in one clean return.

Pick the right code for every outcome and use it everywhere. Consistent status codes make your API predictable and a joy to integrate.

Match the action to the most fitting HTTP status code.

You learned to pair JSON bodies with the right status code by returning a tuple, using 201, 404, and 400 to make your API clear and honest. ✅