* Nginx
* HAProxy

## Let's Encrypt

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

The process to acquire one of these certificates used to be cumbersome, require quite some paperwork and the certificates were quite expensive.

But then **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** was created.

It gives you all the flexibility to choose the ones that fit your project the best.

And you can use directly many well maintained and widely used packages like `passlib` and `python-jose`, because **FastAPI** doesn't require any complex mechanisms to integrate external packages.

But it provides you the tools to simplify the process as much as possible without compromising flexibility, robustness, or security.

    * You can also add [`Security` dependencies with `scopes`](../advanced/security/oauth2-scopes.md){.internal-link target=_blank}.

!!! tip
    Having `dependencies` in the `APIRouter` can be used, for example, to require authentication for a whole group of *path operations*. Even if the dependencies are not added individually to each one of them.

!!! check

---

Common examples of CPU bound operations are things that require complex math processing.

For example:

* **Audio** or **image processing**.
* **Computer vision**: an image is composed of millions of pixels, each pixel has 3 values / colors, processing that normally requires computing something on those pixels, all at the same time.

```

Mais déclare explicitement `q` comme étant un paramètre de requête.

!!! info
    Gardez à l'esprit que la partie la plus importante pour rendre un paramètre optionnel est :

    ```Python
    = None
    ```

    ou :

    ```Python
    = Query(None)
    ```

    et utilisera ce `None` pour détecter que ce paramètre de requête **n'est pas requis**.

It requires a little bit more verbose configurations. And as it is based on WSGI (instead of ASGI), it is not designed to take advantage of the high performance provided by tools like Uvicorn, Starlette and Sanic.

### ⚙️ Pydantic `Required` ↩️ ❕ (`...`)

🚥 👆 💭 😬 ⚙️ `...`, 👆 💪 🗄 & ⚙️ `Required` ⚪️➡️ Pydantic:

```Python hl_lines="2  8"
{!../../../docs_src/query_params_str_validations/tutorial006d.py!}
```

!!! tip

    en tant qu'entier (`int`) Python, pas la chaîne de caractères (`string`) `"3"`.

    Grâce aux déclarations de types, **FastAPI** fournit du
    <abbr title="conversion de la chaîne de caractères venant de la requête HTTP en données Python">"parsing"</abbr> automatique.

## Validation de données

```TypeScript
ItemsService.createItemItemsPost({name: "Plumbus", price: 5})
```

...that's because the client generator uses the OpenAPI internal **operation ID** for each *path operation*.

In this case, it requires the scope `me` (it could require more than one scope).

!!! note
    You don't necessarily need to add different scopes in different places.