In this case, it requires the scope `me` (it could require more than one scope).

!!! note
    You don't necessarily need to add different scopes in different places.

    We are doing it here to demonstrate how **FastAPI** handles scopes declared at different levels.

=== "Python 3.10+"

    ```Python hl_lines="4  139  170"
    {!> ../../../docs_src/security/tutorial005_an_py310.py!}
    ```

!!! tip
    In this example, the variable is called `router`, but you can name it however you want.

We are going to include this `APIRouter` in the main `FastAPI` app, but first, let's check the dependencies and another `APIRouter`.

## Dependencies

We see that we are going to need some dependencies used in several places of the application.

So we put them in their own `dependencies` module (`app/dependencies.py`).

## **FastAPI**'s `OAuth2PasswordBearer`

**FastAPI** provides several tools, at different levels of abstraction, to implement these security features.

In this example we are going to use **OAuth2**, with the **Password** flow, using a **Bearer** token. We do that using the `OAuth2PasswordBearer` class.

!!! info
    A "bearer" token is not the only option.

This code is something you can actually use in your application, save the password hashes in your database, etc.

We are going to start from where we left in the previous chapter and increment it.

## About JWT

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

### Migration

### Multiple Containers

If you have **multiple containers**, probably each one running a **single process** (for example, in a **Kubernetes** cluster), then you would probably want to have a **separate container** doing the work of the **previous steps** in a single container, running a single process, **before** running the replicated worker containers.

!!! info

As query parameters are not a fixed part of a path, they can be optional and can have default values.

In the example above they have default values of `skip=0` and `limit=10`.

So, going to the URL:

```
http://127.0.0.1:8000/items/
```

would be the same as going to:

```
http://127.0.0.1:8000/items/?skip=0&limit=10
```

But if you go to, for example:

```
http://127.0.0.1:8000/items/?skip=20
```

```

But possibly the most important part of the callback is making sure that your API user (the external developer) implements the *external API* correctly, according to the data that *your API* is going to send in the request body of the callback, etc.

So, what we will do next is add the code to document how that *external API* should look like to receive the callback from *your API*.

All in a way that provided the best development experience for all the developers.

## Requirements

After testing several alternatives, I decided that I was going to use <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">**Pydantic**</a> for its advantages.

3. Dieses `yield from` weist die Funktion an, über das Ding namens `file_like` zu iterieren. Und dann für jeden iterierten Teil, diesen Teil so zurückzugeben, als wenn er aus dieser Generatorfunktion (`iterfile`) stammen würde.