from socketify import App, middleware async def get_user(authorization): if authorization: # you can do something async here return {"greeting": "Hello, World"} return None async def auth(res, req, data=None): user = await get_user(req.get_header("authorization")) if not user: res.write_status(403).end("not authorized") # returning Falsy in middlewares just stop the execution of the next middleware return False # returns extra data return user def another_middie(res, req, data=None): # now we can mix sync and async and change the data here if isinstance(data, dict): gretting = data.get("greeting", "") data["greeting"] = f"{gretting} from another middie ;)" return data def home(res, req, user=None): res.cork_end(user.get("greeting", None)) app = App() app.get("/", middleware(auth, another_middie, home)) app.listen( 3000, lambda config: print("Listening on port http://localhost:%d now\n" % config.port), ) app.run() # You can also take a loop on MiddlewareRouter in middleware_router.py ;)