{!../../../docs_src/metadata/tutorial002.py!}
```

If you want to disable the OpenAPI schema completely you can set `openapi_url=None`, that will also disable the documentation user interfaces that use it.

## Docs URLs

You can configure the two documentation user interfaces included:

* **Swagger UI**: served at `/docs`.
    * You can set its URL with the parameter `docs_url`.
    * You can disable it by setting `docs_url=None`.

## OpenAPI Docs URLs

If you needed to, you could use settings and environment variables to configure OpenAPI conditionally depending on the environment, and even disable it entirely.

## About security, APIs, and docs

Hiding your documentation user interfaces in production *shouldn't* be the way to protect your API.

That doesn't add any extra security to your API, the *path operations* will still be available where they are.

<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path`

فریم ورک **FastAPI** بر اساس **OpenAPI** است.

این خاصیت، امکان دارد تا چندین رابط مستندات تعاملی خودکار(automatic interactive documentation interfaces)، تولید کد و غیره وجود داشته باشد.

مشخصه OpenAPI روشی برای تعریف چندین "schemes" دارد.

```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

## 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.

    Notice that the error also clearly states exactly the point where the validation didn't pass.

    This is incredibly helpful while developing and debugging code that interacts with your API.

## Documentation