If you're returning JSON, I'd suggest that you use the `JsonResponse` class defined in `common/djangoapps/util/json_request.py`. It sets some sensible defaults for JSON-formatted responses (like the `content-type`) and is generally easier to use. Also, if you're returning an error response, *please* don't use HTTP status code 200; in this case, you should probably use status code 400, since this is a problem with the request.