* **FastAPI**: (uses Starlette) an API microframework with several additional features for building APIs, with data validation, etc.

* **Uvicorn**:
    * Will have the best performance, as it doesn't have much extra code apart from the server itself.

In the docs UI at <a href="http://127.0.0.1:9999/api/v1/docs" class="external-link" target="_blank">http://127.0.0.1:9999/api/v1/docs</a> it would look like:

<img src="/img/tutorial/behind-a-proxy/image03.png">

!!! tip
    The docs UI will interact with the server that you select.

### Disable automatic server from `root_path`

<font color="#3465A4">INFO    </font> Searching for package file structure from directories with <font color="#3465A4">__init__.py</font> files
<font color="#3465A4">INFO    </font> Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

 ╭─ <font color="#8AE234"><b>Python module file</b></font> ─╮
 │                      │

### 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.

Then create class attributes with fixed values, which will be the available valid values:

    ```

With this, we get tooling support, from editors and mypy as this code is correct in terms of types, but we also get the data filtering from FastAPI.

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.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

One of the main features needed by API systems is data "<abbr title="also called marshalling, conversion">serialization</abbr>" which is taking data from the code (Python) and converting it into something that can be sent through the network. For example, converting an object containing data from a database into a JSON object. Converting `datetime` objects into strings, etc.

You can declare a parameter in a *path operation function* or dependency to be of type `Request` and then you can access the raw request object directly, without any validation, etc.

You can import it directly from `fastapi`:

```python
from fastapi import Request
```

!!! tip

Abhängigkeiten werden hauptsächlich mit der speziellen Funktion `Depends()` behandelt, die ein Callable entgegennimmt.

Hier finden Sie deren Referenz und Parameter.

Sie können sie direkt von `fastapi` importieren:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`

In vielen Szenarien können Sie die Sicherheit (Autorisierung, Authentifizierung usw.) mit Abhängigkeiten handhaben, indem Sie `Depends()` verwenden.

!!! note "Technical Details"
    You could also use `from starlette.testclient import TestClient`.

    **FastAPI** provides the same `starlette.testclient` as `fastapi.testclient` just as a convenience for you, the developer. But it comes directly from Starlette.

!!! tip