And Pydantic's `Field` returns an instance of `FieldInfo` as well.

    `Body` also returns objects of a subclass of `FieldInfo` directly. And there are others you will see later that are subclasses of the `Body` class.

For example:

* <a href="https://docs.sentry.io/platforms/python/guides/fastapi/" class="external-link" target="_blank">Sentry</a>
* <a href="https://github.com/encode/uvicorn/blob/master/uvicorn/middleware/proxy_headers.py" class="external-link" target="_blank">Uvicorn's `ProxyHeadersMiddleware`</a>
* <a href="https://github.com/florimondmanca/msgpack-asgi" class="external-link" target="_blank">MessagePack</a>

* <a href="https://strawberry.rocks/" class="external-link" target="_blank">Strawberry</a> 🍓
    * With <a href="https://strawberry.rocks/docs/integrations/fastapi" class="external-link" target="_blank">docs for FastAPI</a>
* <a href="https://ariadnegraphql.org/" class="external-link" target="_blank">Ariadne</a>

from pydantic import BaseModel

app = FastAPI()


class JsonApiResponse(JSONResponse):
    media_type = "application/vnd.api+json"


class Error(BaseModel):
    status: str
    title: str


class JsonApiError(BaseModel):
    errors: typing.List[Error]


@app.get(
    "/a",
    response_class=JsonApiResponse,
    responses={500: {"description": "Error", "model": JsonApiError}},
)

### Création d'un `Enum`

Importez `Enum` et créez une sous-classe qui hérite de `str` et `Enum`.

En héritant de `str` la documentation sera capable de savoir que les valeurs doivent être de type `string` et pourra donc afficher cette `Enum` correctement.

Créez ensuite des attributs de classe avec des valeurs fixes, qui seront les valeurs autorisées pour cette énumération.

```Python hl_lines="1  6-9"

                </mxCell>
                <mxCell id="90" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;dashed=1;startArrow=none;startFill=0;endArrow=classic;endFill=1;strokeWidth=3;" parent="1" source="101" target="32" edge="1">
                    <mxGeometry relative="1" as="geometry">
                        <mxPoint x="390" y="-190" as="sourcePoint"/>

## À propos de Starlette

Vous ne devriez pas épingler la version de `starlette`.

Différentes versions de **FastAPI** utiliseront une version spécifique plus récente de Starlette.

Ainsi, vous pouvez simplement laisser **FastAPI** utiliser la bonne version de Starlette.

## À propos de Pydantic

Pydantic inclut des tests pour **FastAPI** avec ses propres tests, ainsi les nouvelles versions de Pydantic (au-dessus

            client_secret=client_secret,
        )


class OAuth2(SecurityBase):
    """
    This is the base class for OAuth2 authentication, an instance of it would be used
    as a dependency. All other OAuth2 classes inherit from it and customize it for
    each OAuth2 flow.

    You normally would not create a new class inheriting from it but use one of the

* <a href="https://github.com/tiangolo/full-stack" class="external-link" target="_blank">https://github.com/tiangolo/full-stack</a>
* <a href="https://github.com/tiangolo/full-stack-flask-couchbase" class="external-link" target="_blank">https://github.com/tiangolo/full-stack-flask-couchbase</a>

{!../../../docs_src/cookie_params/tutorial001.py!}
```

!!! note "Detalhes Técnicos"
    `Cookie` é uma classe "irmã" de `Path` e `Query`. Ela também herda da mesma classe em comum `Param`.

    Mas lembre-se que quando você importa `Query`, `Path`, `Cookie` e outras de `fastapi`, elas são na verdade funções que retornam classes especiais.

!!! info "Informação"