```Python hl_lines="2  6-8"
{!../../../docs_src/advanced_middleware/tutorial002.py!}
```

The following arguments are supported:

* `allowed_hosts` - A list of domain names that should be allowed as hostnames. Wildcard domains such as `*.example.com` are supported for matching subdomains. To allow any hostname either use `allowed_hosts=["*"]` or omit the middleware.

!!! note "Technical Details"
    You could also use `from starlette.requests import Request`.

    **FastAPI** provides it as a convenience for you, the developer. But it comes directly from Starlette.

### Before and after the `response`