For new code and whenever possible, use `Annotated` as explained above. There are multiple advantages (explained below) and no disadvantages. 🍰

This is how you would use `Query()` as the default value of your function parameter, setting the parameter `max_length` to 50:

=== "Python 3.10+"

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params_str_validations/tutorial002_py310.py!}
    ```

=== "Python 3.8+"

from fastapi import APIRouter

router = APIRouter()


@router.post("/")
async def update_admin():

### Parallel Burgers

Now let's imagine these aren't "Concurrent Burgers", but "Parallel Burgers".

You go with your crush to get parallel fast food.

    response = client.post(
        "/admin/?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Admin getting schwifty"}


def test_admin_invalid_header(client: TestClient):
    response = client.post("/admin/", headers={"X-Token": "invalid"})
    assert response.status_code == 400, response.text

## Враження

"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._"

## Opinions

"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._"

                """
                The path to the automatic interactive API documentation.
                It is handled in the browser by Swagger UI.

                The default URL is `/docs`. You can disable it by setting it to `None`.

                If `openapi_url` is set to `None`, this will be automatically disabled.

                Read more in the

For example, you could disable syntax highlighting in Swagger UI.

Without changing the settings, syntax highlighting is enabled by default:

<img src="/img/tutorial/extending-openapi/image02.png">

But you can disable it by setting `syntaxHighlight` to `False`:

```Python hl_lines="3"
{!../../../docs_src/configure_swagger_ui/tutorial001.py!}
```

...and then Swagger UI won't show the syntax highlighting anymore:

from fastapi import APIRouter

router = APIRouter()


@router.post("/")
async def update_admin():

from fastapi import APIRouter

router = APIRouter()


@router.post("/")
async def update_admin():