```JSON hl_lines="4-8"
{
    "openapi": "3.1.0",
    // More stuff here
    "servers": [
        {
            "url": "/api/v1"
        }
    ],
    "paths": {
            // More stuff here
    }
}
```

    collected using form data (instead of JSON) and that it should have the specific
    fields `username` and `password`.

    All the initialization parameters are extracted from the request.

    Read more about it in the
    [FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).

    ## Example

    ```python
    from typing import Annotated

It requires a little bit more verbose configurations. And as it is based on WSGI (instead of ASGI), it is not designed to take advantage of the high performance provided by tools like Uvicorn, Starlette and Sanic.

The dependency injection system requires pre-registration of the dependencies and the dependencies are solved based on the declared types. So, it's not possible to declare more than one "component" that provides a certain type.

"Operation" here refers to one of the HTTP "methods".

One of:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...and the more exotic ones:

* `OPTIONS`
* `HEAD`
* `PATCH`
* `TRACE`

In the HTTP protocol, you can communicate to each path using one (or more) of these "methods".

---

When building APIs, you normally use these specific HTTP methods to perform a specific action.

```YAML hl_lines="8"
site_name: FastAPI
# More stuff
nav:
- FastAPI: index.md
- Languages:
  - en: /
  - es: /es/
- features.md
```

* 📂 ⬜ 📁 📁 🇪🇸 👆 ✍, ✅:

```
docs/es/mkdocs.yml
```

* 🚮 ⚫️ 📤 ☑ 🎏 🗺 ⚫️ 🇪🇸, ✅:

```YAML hl_lines="8"
site_name: FastAPI
# More stuff
nav:
- FastAPI: index.md
- Languages:
  - en: /

But most importantly:

* It will **limit and filter** the output data to what is defined in the return type.
    * This is particularly important for **security**, we'll see more of that below.

## `response_model` Parameter

There are some cases where you need or want to return some data that is not exactly what the type declares.

from typing_extensions import Annotated, Doc


class HTTPBasicCredentials(BaseModel):
    """
    The HTTP Basic credentials given as the result of using `HTTPBasic` in a
    dependency.

    Read more about it in the
    [FastAPI docs for HTTP Basic Auth](https://fastapi.tiangolo.com/advanced/security/http-basic-auth/).
    """

    username: Annotated[str, Doc("The HTTP Basic username.")]

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

### Aggiornamento della documentazione alternativa

Ora vai su <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>.

* Anche la documentazione alternativa dell'API mostrerà il nuovo parametro della query e il _body_:

I'll tell you a bit more about these **concepts** here, and that would hopefully give you the **intuition** you would need to decide how to deploy your API in very different environments, possibly even in **future** ones that don't exist yet.

By considering these concepts, you will be able to **evaluate and design** the best way to deploy **your own APIs**.

    ```Python
    {!> ../../../docs_src/python_types/tutorial011.py!}
    ```

!!! info
    To learn more about <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic, check its docs</a>.

**FastAPI** is all based on Pydantic.

You will see a lot more of all this in practice in the [Tutorial - User Guide](tutorial/index.md){.internal-link target=_blank}.

!!! tip