# Path Operation Configuration

There are several parameters that you can pass to your *path operation decorator* to configure it.

!!! warning
    Notice that these parameters are passed directly to the *path operation decorator*, not to your *path operation function*.

## Response Status Code

You can define the (HTTP) `status_code` to be used in the response of your *path operation*.

You can pass directly the `int` code, like `404`.

    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```

In this case, the function parameter `q` will be optional, and will be `None` by default.

!!! check
    Also notice that **FastAPI** is smart enough to notice that the path parameter `item_id` is a path parameter and `q` is not, so, it's a query parameter.

## Query parameter type conversion

You can also declare `bool` types, and they will be converted:

!!! info
    The `app.webhooks` object is actually just an `APIRouter`, the same type you would use when structuring your app with multiple files.

    "paid": true
}
```

and it would expect a response from that *external API* with a JSON body like:

```JSON
{
    "ok": true
}
```

!!! tip
    Notice how the callback URL used contains the URL received as a query parameter in `callback_url` (`https://www.external.org/events`) and also the invoice `id` from inside of the JSON body (`2expen51ve`).

### Add the callback router

            "name": "The Foo live"
        },
        {
            "url": "http://example.com/dave.jpg",
            "name": "The Baz"
        }
    ]
}
```

!!! info
    Notice how the `images` key now has a list of image objects.

## Deeply nested models

You can define arbitrarily deeply nested models:

=== "Python 3.10+"

    ```Python hl_lines="7  12  18  21  25"

And to communicate using WebSockets with your backend you would probably use your frontend's utilities.

Or you might have a native mobile application that communicates with your WebSocket backend directly, in native code.

Or you might have any other way to communicate with the WebSocket endpoint.

---

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="22"
    {!> ../../../docs_src/dependencies/tutorial005.py!}
    ```

!!! info
    Notice that we are only declaring one dependency in the *path operation function*, the `query_or_cookie_extractor`.

):
    await websocket.accept()
    await websocket.send_text(data)
    await websocket.close()


@native_prefix_route.websocket("/")
async def router_native_prefix_ws(websocket: WebSocket):
    await websocket.accept()
    await websocket.send_text("Hello, router with native prefix!")
    await websocket.close()


async def ws_dependency_err():
    raise NotImplementedError()

Und um über WebSockets mit Ihrem Backend zu kommunizieren, würden Sie wahrscheinlich die Werkzeuge Ihres Frontends verwenden.

Oder Sie verfügen möglicherweise über eine native Mobile-Anwendung, die direkt in nativem Code mit Ihrem WebSocket-Backend kommuniziert.

Oder Sie haben andere Möglichkeiten, mit dem WebSocket-Endpunkt zu kommunizieren.

---

participant dep as Dep with yield
participant operation as Path Operation
participant tasks as Background tasks

    Note over client,tasks: Can raise exception for dependency, handled after response is sent
    Note over client,operation: Can raise HTTPException and can change the response
    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise
        dep -->> handler: Raise HTTPException