Ela é importada/incluída diretamente no FastAPI para que você possa importá-la do `fastapi` e evitar a importação acidental da alternativa `BackgroundTask` (sem o `s` no final) de `starlette.background`.

---

**Note** : vous pouvez mélanger `def` et `async def` dans vos *fonctions de chemin* autant que nécessaire, **FastAPI** saura faire ce qu'il faut avec.

Au final, peu importe le cas parmi ceux ci-dessus, **FastAPI** fonctionnera de manière asynchrone et sera extrêmement rapide.

And then, we extend that copy `dict`, adding another key-value pair: `"id": last_record_id`:

```Python
{**note.dict(), "id": last_record_id}
```

So, the final result returned would be something like:

```Python
{
    "id": 1,
    "text": "Some note",
    "completed": False,
}
```

## Check it

<img src="/img/tutorial/security/image02.png">

!!! note
    It doesn't matter what you type in the form, it won't work yet. But we'll get there.

This is of course not the frontend for the final users, but it's a great automatic tool to document interactively all your API.

It can be used by the frontend team (that can also be yourself).

It can be used by third party applications and systems.

Então ele constrói todos aqueles _sites_ independentes MkDocs para cada linguagem, combina eles, e gera a saída final em `./site/`.

Então você poderá "servir" eles com o comando `serve`:

<div class="termy">

```console
// Use o comando "serve" após rodar "build-all"
$ python ./scripts/docs.py serve

And if you declared a `response_model`, it will still be used to filter and convert the object you returned.

**FastAPI** will use that *temporal* response to extract the cookies (also headers and status code), and will put them in the final response that contains the value you returned, filtered by any `response_model`.

You can also declare the `Response` parameter in dependencies, and set cookies (and headers) in them.

## Return a `Response` directly

    * You wouldn't write an application in Uvicorn directly. That would mean that your code would have to include more or less, at least, all the code provided by Starlette (or **FastAPI**). And if you did that, your final application would have the same overhead as having used a framework and minimizing your app code and bugs.
    * If you are comparing Uvicorn, compare it against Daphne, Hypercorn, uWSGI, etc. Application servers.
* **Starlette**:

    * No escribirías una aplicación directamente en Uvicorn. Eso significaría que tu código tendría que incluir más o menos, al menos, todo el código proporcionado por Starlette (o **FastAPI**). Y si hicieras eso, tu aplicación final tendría la misma sobrecarga que si hubieras usado un framework y minimizado el código de tu aplicación y los errores.
    * Si estás comparando Uvicorn, compáralo con los servidores de aplicaciones Daphne, Hypercorn, uWSGI, etc.

As the path of each *path operation* has to start with `/`, like in:

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...the prefix must not include a final `/`.

So, the prefix in this case is `/items`.

We can also add a list of `tags` and extra `responses` that will be applied to all the *path operations* included in this router.

E então esperando novamente pelas respostas voltarem.

Essa "espera" é medida em microssegundos, e ainda assim, somando tudo, é um monte de espera no final.

Por isso que faz muito mais sentido utilizar código assíncrono para APIs web.