"legacy_request_state_context_var", default=None
)

app = FastAPI()


async def set_up_request_state_dependency():
    request_state = {"user": "deadpond"}
    contextvar_token = legacy_request_state_context_var.set(request_state)
    yield request_state
    legacy_request_state_context_var.reset(contextvar_token)


@app.middleware("http")
async def custom_middleware(

    "legacy_request_state_context_var", default=None
)

async def set_up_request_state_dependency():
    request_state = {"user": "deadpond"}
    contextvar_token = legacy_request_state_context_var.set(request_state)
    yield request_state
    legacy_request_state_context_var.reset(contextvar_token)
```

        async def app(scope: Scope, receive: Receive, send: Send) -> None:
            # Starts customization
            response_awaited = False
            async with AsyncExitStack() as request_stack:
                scope["fastapi_inner_astack"] = request_stack
                async with AsyncExitStack() as function_stack:
                    scope["fastapi_function_astack"] = function_stack
                    response = await f(request)