Changelog

New updates and improvements at Cloudflare.

Python Workers handlers now live in an entrypoint class

Aug 14, 2025

We are changing how Python Workers are structured by default. Previously, handlers were defined at the top-level of a module as on_fetch, on_scheduled, etc. methods, but now they live in an entrypoint class.

Here's an example of how to now define a Worker with a fetch handler:

from workers import Response, WorkerEntrypoint

class Default(WorkerEntrypoint):
    async def fetch(self, request):
        return Response("Hello World!")

To keep using the old-style handlers, you can specify the disable_python_no_global_handlers compatibility flag in your wrangler file:

wrangler.jsonc
wrangler.toml

{
  "compatibility_flags": [
    "disable_python_no_global_handlers"
  ]
}

compatibility_flags = [ "disable_python_no_global_handlers" ]

Consult the Python Workers documentation for more details.