Note that the dev server is running in WSGI mode

[Matthew Pava]

With the mass adoption of async Django on the way, we need to provide a clearer warning in the development server that it is running in WSGI mode and not ASGI mode. I spent an hour troubleshooting a warning because I created a middleware that was async only. Only when I made it compatible for both async and sync modes did the warning go away.

Or we could just make the Django dev server default to ASGI mode.

Actual result:
The Django server displays this warning:
WARNING: This is a development server. Do not use it in a production setting. Use a production WSGI or ASGI server instead.
For more information on production servers see: ​https://docs.djangoproject.com/en/6.0/howto/deployment/

Desired result:
Revise it to something like:
WARNING: This is a development server that is running only in sync mode (WSGI). Only middleware that is compatible with sync mode (WSGI) will run properly. Do not use it in a production setting. Use a production WSGI or ASGI server instead.

[Jacob Walls]

In general, this seems fine to tweak. I checked Daphne's runserver output, and it looks like:

Starting ASGI/Daphne version 4.2.1 development server at http://127.0.0.1:8000/

So I'd be happy to change Django's to:

django/core/management/commands/runserver.py

@@ -184 +184 @@
         print(
             f"{now}\n"
             f"Django version {version}, using settings {settings.SETTINGS_MODULE!r}\n"
-            f"Starting development server at {self.protocol}://{addr}:{server_port}/\n"
+            f"Starting WSGI development server at {self.protocol}://{addr}:{server_port}/\n"
             f"Quit the server with {quit_command}.",
             file=self.stdout,
         )

However, mixing this information up with the security warning doesn't seem appropriate to me, nor taking a detour into middleware.

[Matthew Pava]

That's fine. Can we also update the middleware documentation with some note that the development server only supports sync middleware?
​https://docs.djangoproject.com/en/6.0/topics/http/middleware/

[Jacob Walls]

Either there or on the async support page seems reasonable.