grant_type: the OAuth2 spec says it is required and MUST be the fixed string "password".
        This dependency is strict about it. If you want to be permissive, use instead the
        OAuth2PasswordRequestForm dependency class.
    username: username string. The OAuth2 spec requires the exact field name "username".
    password: password string. The OAuth2 spec requires the exact field name "password".

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.

# OpenAPI

There are several utilities to handle OpenAPI.

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

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

[build-system]
requires = ["pdm-backend"]
build-backend = "pdm.backend"

[project]
name = "fastapi"
dynamic = ["version"]
description = "FastAPI framework, high performance, easy to learn, fast to code, ready for production"
readme = "README.md"
requires-python = ">=3.8"
authors = [
    { name = "Sebastián Ramírez", email = "******@****.***" },
]
classifiers = [
    "Intended Audience :: Information Technology",

needs_py39 = pytest.mark.skipif(sys.version_info < (3, 9), reason="requires python3.9+")
needs_py310 = pytest.mark.skipif(
    sys.version_info < (3, 10), reason="requires python3.10+"
)
needs_pydanticv2 = pytest.mark.skipif(not PYDANTIC_V2, reason="requires Pydantic v2")

    # Messages to create or check
    new_translation_message = f"Good news everyone! 😉 There's a new translation PR to be reviewed: #{pr.number} by @{pr.user.login}. 🎉 This requires 2 approvals from native speakers to be merged. 🤓"
    done_translation_message = f"~There's a new translation PR to be reviewed: #{pr.number} by @{pr.user.login}~ Good job! This is done. 🍰☕"

<div class="termy">

```console
$ pip install "python-jose[cryptography]"

---> 100%
```

</div>

<a href="https://github.com/mpdavis/python-jose" class="external-link" target="_blank">Python-jose</a> requires a cryptographic backend as an extra.

Here we are using the recommended one: <a href="https://cryptography.io/" class="external-link" target="_blank">pyca/cryptography</a>.

!!! tip

    ```

!!! info
    Notice that `response_description` refers specifically to the response, the `description` refers to the *path operation* in general.

!!! check
    OpenAPI specifies that each *path operation* requires a response description.

    So, if you don't provide one, **FastAPI** will automatically generate one of "Successful response".

<img src="/img/tutorial/path-operation-configuration/image03.png">

!!! note
    **FastAPI** saura que la valeur de `q` n'est pas requise grâce à la valeur par défaut `= None`.

    Le `Union` dans `Union[str, None]` permettra à votre éditeur de vous offrir un meilleur support et de détecter les erreurs.

## Validation additionnelle