`OAuth2PasswordBearer` makes **FastAPI** know that it is a security scheme. So it is added that way to OpenAPI.

    But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

    But as it's a common use case, it is provided by **FastAPI** directly, just to make it easier.

### Use the form data

!!! tip

    In Pydantic version 1, you would use an internal class `Config` and `schema_extra`, as described in <a href="https://docs.pydantic.dev/1.10/usage/schema/#schema-customization" class="external-link" target="_blank">Pydantic's docs: Schema customization</a>.

    You can set `schema_extra` with a `dict` containing any additional data you would like to show up in the generated JSON Schema, including `examples`.

!!! tip

fluffy = Cat(name="Mr Fluffy")
```

In this case, `fluffy` is an instance of the class `Cat`.

And to create `fluffy`, you are "calling" `Cat`.

So, a Python class is also a **callable**.

Then, in **FastAPI**, you could use a Python class as a dependency.

What FastAPI actually checks is that it is a "callable" (function, class or anything else) and the parameters defined.

    ```Python hl_lines="10  15"
    {!> ../../../docs_src/request_files/tutorial002.py!}
    ```

You will receive, as declared, a `list` of `bytes` or `UploadFile`s.

!!! note "Technical Details"
    You could also use `from starlette.responses import HTMLResponse`.

For example, let's say you have 4 API endpoints (*path operations*):

* `/items/public/`
* `/items/private/`
* `/users/{user_id}/activate`
* `/items/pro/`

then you could add different permission requirements for each of them just with dependencies and sub-dependencies:

```mermaid
graph TB

current_user(["current_user"])
active_user(["active_user"])
admin_user(["admin_user"])

        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1
        {
            "detail": [
                {
                    "loc": ["path", "item_id"],
                    "msg": "value could not be parsed to a boolean",
                    "type": "type_error.bool",
                }
            ]
        }
    )


def test_path_bool_True():
    response = client.get("/path/bool/True")

---

> Büyük, kirli bir evi temizlemelisin.

*Evet, tüm hikaye bu*.

---

Beklemek yok 🕙. Hiçbir yerde.  Sadece evin birden fazla yerinde yapılacak fazlasıyla iş var.

You could have turns as in the burgers example, first the living room, then the kitchen, but as you are not waiting 🕙 for anything, just cleaning and cleaning, the turns wouldn't affect anything.

            """
        ),
    ] = None,
) -> HTMLResponse:
    """
    Generate and return the HTML  that loads Swagger UI for the interactive
    API docs (normally served at `/docs`).

    You would only call this function yourself if you needed to override some parts,
    for example the URLs to use to load Swagger UI's JavaScript and CSS.

    Read more about it in the

---