* Convert from and to JSON automatically.
* Document everything with OpenAPI, that can be used by:
    * Interactive documentation systems.
    * Automatic client code generation systems, for many languages.
* Provide 2 interactive documentation web interfaces directly.

---

We just scratched the surface, but you already get the idea of how it all works.

Try changing the line with:

    """
    API key authentication using a query parameter.

    This defines the name of the query parameter that should be provided in the request
    with the API key and integrates that into the OpenAPI documentation. It extracts
    the key value sent in the query parameter automatically and provides it as the
    dependency result. But it doesn't define how to send that API key to the client.

    ## Usage

# OpenAPI `docs`

Utilities to handle OpenAPI automatic UI documentation, including Swagger UI (by default at `/docs`) and ReDoc (by default at `/redoc`).

::: fastapi.openapi.docs.get_swagger_ui_html

::: fastapi.openapi.docs.get_redoc_html

::: fastapi.openapi.docs.get_swagger_ui_oauth2_redirect_html

Extrait de la documentation officielle de **Pydantic** :

```Python
{!../../../docs_src/python_types/tutorial011.py!}
```

!!! info
    Pour en savoir plus à propos de <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic, allez jeter un coup d'oeil à sa documentation</a>.

**FastAPI** est basé entièrement sur **Pydantic**.

## Documents OpenAPI et API

Si vous renvoyez directement des codes HTTP et des réponses supplémentaires, ils ne seront pas inclus dans le schéma OpenAPI (la documentation de l'API), car FastAPI n'a aucun moyen de savoir à l'avance ce que vous allez renvoyer.

to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

To see all the available parameters and options, check the <a href="https://www.starlette.io/responses/#set-cookie" class="external-link" target="_blank">documentation in Starlette</a>....

    img: https://fastapi.tiangolo.com/img/sponsors/porter.png
  - url: https://bump.sh/fastapi?utm_source=fastapi&utm_medium=referral&utm_campaign=sponsor
    title: Automate FastAPI documentation generation with Bump.sh
    img: https://fastapi.tiangolo.com/img/sponsors/bump-sh.svg
  - url: https://reflex.dev
    title: Reflex
    img: https://fastapi.tiangolo.com/img/sponsors/reflex.png

安装完 CLI 后，打开新的 Terminal，就能检测到刚安装的 CLI。

在新的 Terminal 里，用以下命令确认 CLI 是否正确安装：

<div class="termy">

```console
$ deta --help

Deta command line interface for managing deta micros.
Complete documentation available at https://docs.deta.sh

Usage:
  deta [flags]
  deta [command]

Available Commands:
  auth        Change auth settings for a deta micro

...
```

</div>

Et ces fichiers Python sont inclus/injectés dans la documentation lors de la génération du site.

### Documentation pour les tests

La plupart des tests sont en fait effectués par rapport aux exemples de fichiers sources dans la documentation.

Cela permet de s'assurer que :

* La documentation est à jour.
* Les exemples de documentation peuvent être exécutés tels quels.

     * URL はパラメータ `docs_url` で設定できます。
     * `docs_url=None` を設定することで無効にできます。
* ReDoc: `/redoc` で提供されます。
     * URL はパラメータ `redoc_url` で設定できます。
     * `redoc_url=None` を設定することで無効にできます。

たとえば、`/documentation` でSwagger UIが提供されるように設定し、ReDocを無効にするには:

```Python hl_lines="3"
{!../../../docs_src/metadata/tutorial003.py!}