**FastAPI** is based on **OpenAPI**.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

By using them, you can take advantage of all these standard-based tools, including these interactive documentation systems.

**FastAPI** é baseado no **OpenAPI**.

Isso é o que torna possível ter múltiplas automações interativas de interfaces de documentação, geração de código, etc.

OpenAPI tem uma forma para definir múltiplos “esquemas” de segurança.

=== "Python 3.8+"

    ```Python hl_lines="17  22  27"
    {!> ../../../docs_src/path_operation_configuration/tutorial002.py!}
    ```

They will be added to the OpenAPI schema and used by the automatic documentation interfaces:

<img src="/img/tutorial/path-operation-configuration/image01.png">

### Tags with Enums

        Doc(
            """
            OpenAPI-specific examples.

            It will be added to the generated OpenAPI (e.g. visible at `/docs`).

            Swagger UI (that provides the `/docs` interface) has better support for the
            OpenAPI-specific examples than the JSON Schema `examples`, that's the main
            use case for this.

            Read more about it in the

```Python hl_lines="1  7-13  19"
{!../../../docs_src/dataclasses/tutorial002.py!}
```

The dataclass will be automatically converted to a Pydantic dataclass.

This way, its schema will show up in the API docs user interface:

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses in Nested Data Structures

You can also combine `dataclasses` with other type annotations to make nested data structures.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares

As **FastAPI** is based on Starlette and implements the <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr> specification, you can use any ASGI middleware.

A middleware doesn't have to be made for FastAPI or Starlette to work, as long as it follows the ASGI spec.

!!! tip

<a href="https://typer.tiangolo.com" target="_blank"><img src="https://typer.tiangolo.com/img/logo-margin/logo-margin-vector.svg" style="width: 20%;"></a>

Se stai sviluppando un'app <abbr title="Command Line Interface (interfaccia della riga di comando)">CLI</abbr> da usare nel terminale invece che una web API, ti consigliamo <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>.

=== "Python 3.10 and above"

    ```Python hl_lines="15  20  25"
    {!> ../../../docs_src/path_operation_configuration/tutorial002_py310.py!}
    ```

Eles serão adicionados ao esquema OpenAPI e usados pelas interfaces de documentação automática:

<img src="/img/tutorial/path-operation-configuration/image01.png">

### Tags com Enums

## ASGI Servers

Let's go a little deeper into the details.

FastAPI uses a standard for building Python web frameworks and servers called <abbr title="Asynchronous Server Gateway Interface">ASGI</abbr>. FastAPI is an ASGI web framework.