I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

    ```Python hl_lines="1"
    async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
        return {"fresh_value": fresh_value}
    ```

## Recap

Apart from all the fancy words used here, the **Dependency Injection** system is quite simple.

Just functions that look the same as the *path operation functions*.

## Pin your `fastapi` version

The first thing you should do is to "pin" the version of **FastAPI** you are using to the specific latest version that you know works correctly for your application.

For example, let's say you are using version `0.45.0` in your app.

Para aprender o básico de HTTPS de uma perspectiva do usuário, verifique <a href="https://howhttps.works/pt-br/" class="external-link" target="_blank">https://howhttps.works/pt-br/</a>.

Agora, a partir de uma perspectiva do desenvolvedor, aqui estão algumas coisas para ter em mente ao pensar em HTTPS:

Do you want to just have a `str`? Or just a `dict`? Or a database class model instance directly? It all works the same way.

You actually don't have users that log in to your application but robots, bots, or other systems, that have just an access token? Again, it all works the same.

# Middleware

You can add middleware to **FastAPI** applications.

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.

This way, you can get the best of both worlds: type annotations with **tooling support** and **data filtering**.

## See it in the docs

When you see the automatic docs, you can check that the input model and output model will both have their own JSON Schema:

                                    "normal": {
                                        "summary": "A normal example",
                                        "description": "A **normal** item works correctly.",
                                        "value": {
                                            "name": "Foo",
                                            "description": "A very nice Item",

Um **die Grundlagen von HTTPS** aus Sicht des Benutzers zu erlernen, schauen Sie sich <a href="https://howhttps.works/" class="external-link" target="_blank">https://howhttps.works/</a> an.

Aus **Sicht des Entwicklers** sollten Sie beim Nachdenken über HTTPS Folgendes beachten:

* Für HTTPS muss **der Server** über von einem **Dritten** generierte **„Zertifikate“** verfügen.

=== "Python 3.8+ non-Annotated"

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

    ```Python hl_lines="11-14"
    {!> ../../../docs_src/body_fields/tutorial001.py!}
    ```

`Field` works the same way as `Query`, `Path` and `Body`, it has all the same parameters, etc.

!!! note "Technical Details"