```

## `Union` or `anyOf`

You can declare a response to be the `Union` of two types, that means, that the response would be any of the two.

It will be defined in OpenAPI with `anyOf`.

To do that, use the standard Python type hint <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

!!! note

    `Body` gibt auch Instanzen einer Unterklasse von `FieldInfo` zurück. Und später werden Sie andere sehen, die Unterklassen der `Body`-Klasse sind.

    Denken Sie daran, dass `Query`, `Path` und andere von `fastapi` tatsächlich Funktionen sind, die spezielle Klassen zurückgeben.

!!! tip "Tipp"

        * `password`: some next chapters will cover examples of this.
* `openIdConnect`: has a way to define how to discover OAuth2 authentication data automatically.
    * This automatic discovery is what is defined in the OpenID Connect specification.


!!! tip
    Integrating other authentication/authorization providers like Google, Facebook, Twitter, GitHub, etc. is also possible and relatively easy.

    """

    def __init__(
        self,
        code: Annotated[
            int,
            Doc(
                """
                A closing code from the
                [valid codes defined in the specification](https://datatracker.ietf.org/doc/html/rfc6455#section-7.4.1).
                """
            ),
        ],
        reason: Annotated[
            Union[str, None],
            Doc(

  docs-all-green:  # This job does nothing and is only used for the branch protection
    if: always()
    needs:
      - build-docs
    runs-on: ubuntu-latest
    steps:
      - name: Decide whether the needed jobs succeeded or failed
        uses: re-actors/alls-green@release/v1
        with:
          jobs: ${{ toJSON(needs) }}

The dictionary in `openapi_extra` will be deeply merged with the automatically generated OpenAPI schema for the *path operation*.

So, you could add additional data to the automatically generated schema.

For example, you could decide to read and validate the request with your own code, without using the automatic features of FastAPI with Pydantic, but you could still want to define the request in the OpenAPI schema.

You could do that with `openapi_extra`: