**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.

OpenAPI defines the following security schemes:

* The _path_ `/items/{item_id}` has an optional `str` _query parameter_ `q`.

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>):

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

## Check it

Go to the interactive docs at: <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see something like this:

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

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.

با استفاده از آن‌ها، شما می‌توانید از همه این ابزارهای مبتنی بر استاندارد استفاده کنید، از جمله این سیستم‌های مستندات تعاملی(interactive documentation systems).

استاندارد OpenAPI شیوه‌های امنیتی زیر را تعریف می‌کند:

    Sending a body with a `GET` request has an undefined behavior in the specifications, nevertheless, it is supported by FastAPI, only for very complex/extreme use cases.

    As it is discouraged, the interactive docs with Swagger UI won't show the documentation for the body when using `GET`, and proxies in the middle might not support it.

## Import Pydantic's `BaseModel`

First, you need to import `BaseModel` from `pydantic`:

### Documentation API interactive

Maintenant, rendez-vous sur <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

Vous verrez la documentation interactive automatique de l'API (fournie par <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>) :

You will see the JSON response as:

```JSON
{"message": "Hello World"}
```

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>):

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

!!! check
    Again, just with that same Python type declaration, **FastAPI** gives you automatic, interactive documentation (integrating Swagger UI).

    Notice that the path parameter is declared to be an integer.

* The _path_ `/items/{item_id}` has an optional `str` _query parameter_ `q`.

### Interactive API docs

Now go to <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

You will see the automatic interactive API documentation (provided by <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>):

  private var failFastResponse: MockResponse? = null

  @Throws(InterruptedException::class)
  override fun dispatch(request: RecordedRequest): MockResponse {
    // To permit interactive/browser testing, ignore requests for favicons.
    val requestLine = request.requestLine
    if (requestLine == "GET /favicon.ico HTTP/1.1") {
      logger.info("served $requestLine")