All the security utilities that integrate with OpenAPI (and the automatic API docs) inherit from `SecurityBase`, that's how **FastAPI** can know how to integrate them in OpenAPI.

## What it does

    ```Python hl_lines="9"
    {!> ../../../docs_src/cookie_params/tutorial001.py!}
    ```

!!! note "Technical Details"
    `Cookie` is a "sister" class of `Path` and `Query`. It also inherits from the same common `Param` class.

    But remember that when you import `Query`, `Path`, `Cookie` and others from `fastapi`, those are actually functions that return special classes.

!!! info

### Create an `Enum` class

Import `Enum` and create a sub-class that inherits from `str` and from `Enum`.

By inheriting from `str` the API docs will be able to know that the values must be of type `string` and will be able to render correctly.

```

</div>

Now you can check in your code editor the newly created directory `docs/ht/`.

That command created a file `docs/ht/mkdocs.yml` with a simple config that inherits everything from the `en` version:

```yaml
INHERIT: ../en/mkdocs.yml
```

!!! tip
    You could also simply create that file with those contents manually.

```Python hl_lines="1"
{!../../../docs_src/first_steps/tutorial001.py!}
```

`FastAPI` is a Python class that provides all the functionality for your API.

!!! note "Technical Details"
    `FastAPI` is a class that inherits directly from `Starlette`.

    You can use all the <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> functionality with `FastAPI` too.

### Step 2: create a `FastAPI` "instance"

How does this work? Let's check that out. 🤓

### Type Annotations and Tooling

First let's see how editors, mypy and other tools would see this.

`BaseUser` has the base fields. Then `UserIn` inherits from `BaseUser` and adds the `password` field, so, it will include all the fields from both models.

We annotate the function return type as `BaseUser`, but we are actually returning a `UserIn` instance.

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="7"
    {!> ../../../docs_src/request_files/tutorial001.py!}
    ```

!!! info
    `File` is a class that inherits directly from `Form`.

    But remember that when you import `Query`, `Path`, `File` and others from `fastapi`, those are actually functions that return special classes.

!!! tip

!!! check "**FastAPI** uses it to"
    Handle all the core web parts. Adding features on top.

    The class `FastAPI` itself inherits directly from the class `Starlette`.

    So, anything that you can do with Starlette, you can do it directly with **FastAPI**, as it is basically Starlette on steroids.

With `Form` you can declare the same configurations as with `Body` (and `Query`, `Path`, `Cookie`), including validation, examples, an alias (e.g. `user-name` instead of `username`), etc.

!!! info
    `Form` is a class that inherits directly from `Body`.

!!! tip
    To declare form bodies, you need to use `Form` explicitly, because without it the parameters would be interpreted as query parameters or body (JSON) parameters.

## About "Form Fields"

    ```

=== "Python 3.8+"

    ```Python hl_lines="4"
    {!> ../../../docs_src/body/tutorial001.py!}
    ```

## Create your data model

Then you declare your data model as a class that inherits from `BaseModel`.

Use standard Python types for all the attributes:

=== "Python 3.10+"

    ```Python hl_lines="5-9"
    {!> ../../../docs_src/body/tutorial001_py310.py!}
    ```

=== "Python 3.8+"