```

/// note

You can only use `await` inside of functions created with `async def`.

///

---

If you are using a third party library that communicates with something (a database, an API, the file system, etc.) and doesn't have support for using `await`, (this is currently the case for most database libraries), then declare your *path operation functions* as normally, with just `def`, like:

```Python hl_lines="2"
@app.get('/')

OAuth2 con scopes es el mecanismo usado por muchos grandes proveedores de autenticación, como Facebook, Google, GitHub, Microsoft, X (Twitter), etc. Lo usan para proporcionar permisos específicos a usuarios y aplicaciones.

Cada vez que te "logueas con" Facebook, Google, GitHub, Microsoft, X (Twitter), esa aplicación está usando OAuth2 con scopes.

    * Los contenidos están **encriptados**, aunque se envién con el **protocolo HTTP**.

And then you can set headers in that *temporal* response object.

{* ../../docs_src/response_headers/tutorial002.py hl[1, 7:8] *}

And then you can return any object you need, as you normally would (a `dict`, a database model, etc).

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

## Metadatos OpenAPI - Documentación

Para agregar metadatos a tu esquema de OpenAPI, incluyendo una licencia, versión, contacto, etc, lee la documentación para [Tutorial - Metadatos y URLs de Documentación](../tutorial/metadata.md){.internal-link target=_blank}.

## URL Personalizada de OpenAPI

A dependência original pode estar sendo utilizada em uma *função de operação de rota*, um *docorador de operação de rota* (quando você não utiliza o valor retornado), uma chamada ao `.include_router()`, etc.

O FastAPI ainda poderá sobrescrevê-lo.

///

E então você pode redefinir as suas sobreposições (removê-las) definindo o `app.dependency_overrides` como um `dict` vazio:

```Python
app.dependency_overrides = {}

## OpenAPI Metadata - Docs { #openapi-metadata-docs }

To add metadata to your OpenAPI schema, including a license, version, contact, etc, read the docs for [Tutorial - Metadata and Docs URLs](../tutorial/metadata.md){.internal-link target=_blank}.

## OpenAPI Custom URL { #openapi-custom-url }

            e -> e instanceof InvocationTargetException,
            StackOverflowError.class,
            e -> e instanceof StackOverflowError);
      }
    };

    // used under GWT, etc., since the override of this method does not exist there
    ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
      return ImmutableMap.of();
    }
  }

      This is a list of attachments to the main artifact produced by building the current POM.
      Attachments are derived works, based on the main build process, such as an ejb-client jar,
      project sources jar, etc.
    ]]></description>
  </expression>
</expressions>

* Passer la donnée reçue dans le paramètre `item`.
    * Ce paramètre ayant été déclaré dans la fonction comme étant de type `Item`, vous aurez aussi tout le support offert par l'éditeur (auto-complétion, etc.) pour tous les attributs de ce paramètre et les types de ces attributs.