Workers - Python Workers handlers now live in an entrypoint class

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 { " compatibility_flags " : [ "disable_python_no_global_handlers" ] } wrangler.toml compatibility_flags = [ "disable_python_no_global_handlers" ] Consult the Python Workers documentation for more details.