"404": {
                            "description": "Not found if GraphiQL or query via GET are not enabled.",
                        },
                    },
                    "summary": "Handle Http Get",
                },
                "post": {
                    "operationId": "handle_http_post_graphql_post",
                    "responses": {
                        "200": {

# Advanced Middleware { #advanced-middleware }

In the main tutorial you read how to add [Custom Middleware](../tutorial/middleware.md){.internal-link target=_blank} to your application.

And then you also read how to handle [CORS with the `CORSMiddleware`](../tutorial/cors.md){.internal-link target=_blank}.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares { #adding-asgi-middlewares }

## Use Case { #use-case }

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

The same models are shared among requests, so, it's not one model per request, or one per user or something similar.

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

///

## Types and validation { #types-and-validation }

These environment variables can only handle text strings, as they are external to Python and have to be compatible with other programs and the rest of the system (and even with different operating systems, as Linux, Windows, macOS).

If there's no `gzip` in the header, it will not try to decompress the body.

That way, the same route class can handle gzip compressed or uncompressed requests.

{* ../../docs_src/custom_request_and_route/tutorial001_an_py310.py hl[9:16] *}

### Create a custom `GzipRoute` class { #create-a-custom-gziproute-class }

- ✅ Tests with [Pytest](https://pytest.org).
- 📞 [Traefik](https://traefik.io) as a reverse proxy / load balancer.
- 🚢 Deployment instructions using Docker Compose, including how to set up a frontend Traefik proxy to handle automatic HTTPS certificates.

When a WebSocket connection is closed, the `await websocket.receive_text()` will raise a `WebSocketDisconnect` exception, which you can then catch and handle like in this example.

{* ../../docs_src/websockets/tutorial003_py39.py hl[79:81] *}

To try it out:

* Open the app with several browser tabs.
* Write messages from them.
* Then close one of the tabs.

                        // Handle array type
                        attributes.put(name, parseArray(jsonParser));
                    } else if (jsonParser.getCurrentToken() == JsonToken.START_OBJECT) {
                        // Handle nested object type
                        attributes.put(name, parseObject(jsonParser));
                    } else {
                        // Handle primitive types (string, number, boolean, etc.)

def _get_signature(call: Callable[..., Any]) -> inspect.Signature:
    if sys.version_info >= (3, 10):
        try:
            signature = inspect.signature(call, eval_str=True)
        except NameError:
            # Handle type annotations with if TYPE_CHECKING, not used by FastAPI
            # e.g. dependency return types
            signature = inspect.signature(call)
    else:
        signature = inspect.signature(call)