```

So, **FastAPI** will take care of filtering out all the data that is not declared in the output model (using Pydantic).

### `response_model` or Return Type

In this case, because the two models are different, if we annotated the function return type as `UserOut`, the editor and tools would complain that we are returning an invalid type, as those are different classes.

        return data
    ```

    Note that for OAuth2 the scope `items:read` is a single scope in an opaque string.
    You could have custom internal logic to separate it by colon caracters (`:`) or
    similar, and get the two parts `items` and `read`. Many applications do that to
    group and organize permissions, you could do it as well in your application, just
    know that that it is application specific, it's not part of the specification.
    """

    * <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a>
    * <a href="https://github.com/Rebilly/ReDoc" class="external-link" target="_blank">ReDoc</a>

    These two were chosen for being fairly popular and stable, but doing a quick search, you could find dozens of alternative user interfaces for OpenAPI (that you can use with **FastAPI**).

### Flask REST frameworks

                        "content": {
                            "application/json": {



...
```

#### What is OpenAPI for

The OpenAPI schema is what powers the two interactive documentation systems included.

And there are dozens of alternatives, all based on OpenAPI. You could easily add any of those alternatives to your application built with **FastAPI**.

You can continue with the previous instructions for an "Existing Language" for that process.

You can make the first pull request with those two files, `docs/ht/mkdocs.yml` and `docs/ht/index.md`. 🎉

#### Preview the result

As already mentioned above, you can use the `./scripts/docs.py` with the `live` command to preview the results (or `mkdocs serve`).

                "summary": "Example One Summary",
                "description": "Example One Description",
                "value": {"data": "Data in Body examples, example1"},
            },
            "Example Two": {
                "value": {"data": "Data in Body examples, example2"},
            },
        },
    ),
):
    return item


@app.get("/path_examples/{item_id}")
def path_examples(

### Multiple Processes - An Example

In this example, there's a **Manager Process** that starts and controls two **Worker Processes**.

This Manager Process would probably be the one listening on the **port** in the IP. And it would transmit all the communication to the worker processes.

But that file doesn't exist, our dependencies are in a file at `app/dependencies.py`.

Remember how our app/file structure looks like:

<img src="/img/tutorial/bigger-applications/package.svg">

---

The two dots `..`, like in:

```Python
from ..dependencies import get_token_header
```

mean:

Do you like **FastAPI**?

Would you like to help FastAPI, other users, and the author?

Or would you like to get help with **FastAPI**?

There are very simple ways to help (several involve just one or two clicks).

And there are several ways to get help too.

## Subscribe to the newsletter

    would be valid to use as a **FastAPI** dependency.

    In fact, FastAPI uses those two decorators internally.

## A database dependency with `yield`

For example, you could use this to create a database session and close it after finishing.