* The _path_ `/items/{item_id}` has an optional `str` _query parameter_ `q`.

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>):

### Documentation API interactive

Maintenant, rendez-vous sur <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

Vous verrez la documentation interactive automatique de l'API (fournie par <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>) :

* The _path_ `/items/{item_id}` has an optional `str` _query parameter_ `q`.

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>):

### Automatic docs

Interactive API documentation and exploration web user interfaces. As the framework is based on OpenAPI, there are multiple options, 2 included by default.

* <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank"><strong>Swagger UI</strong></a>, with interactive exploration, call and test your API directly from the browser.

### Documentation automatique

Documentation d'API interactive et interface web d'exploration. Comme le framework est basé sur OpenAPI, de nombreuses options sont disponibles. Deux d'entre-elles sont incluses par défaut.

* <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank"><strong>Swagger UI</strong></a>, propose une documentation interactive. Vous permet de directement tester l'API depuis votre navigateur.

You will see the JSON response as:

```JSON
{"message": "Hello World"}
```

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>):

## Integrated with OpenAPI

All the request declarations, validations and requirements of your dependencies (and sub-dependencies) will be integrated in the same OpenAPI schema.

So, the interactive docs will have all the information from these dependencies too:

<img src="/img/tutorial/dependencies/image01.png">

## Simple usage

```

!!! warning
    A `Response` returned directly by your *path operation function* won't be documented in OpenAPI (for example, the `Content-Type` won't be documented) and won't be visible in the automatic interactive docs.

!!! info
    Of course, the actual `Content-Type` header, status code, etc, will come from the `Response` object you returned.

### Document in OpenAPI and override `Response`

documentation générée automatiquement et interactive :

<img src="/img/tutorial/path-params/image01.png">

!!! info
    À nouveau, en utilisant uniquement les déclarations de type Python, **FastAPI** vous fournit automatiquement une documentation interactive (via Swagger UI).

    On voit bien dans la documentation que `item_id` est déclaré comme entier.

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

By creating these Pydantic models, the input data will be validated, serialized (converted), and annotated (documented).

So, you will be able to see it all in the interactive API docs.

## Connect and disconnect

* Create your `FastAPI` application.
* Create event handlers to connect and disconnect from the database.

```Python hl_lines="42  45-47  50-52"