### Check the docs UI

But here's the fun part. ✨

The "official" way to access the app would be through the proxy with the path prefix that we defined. So, as we would expect, if you try the docs UI served by Uvicorn directly, without the path prefix in the URL, it won't work, because it expects to be accessed through the proxy.

    ```

=== "Python 3.8+"

    ```Python hl_lines="9  11  16"
    {!> ../../../docs_src/response_model/tutorial003.py!}
    ```

Here, even though our *path operation function* is returning the same input user that contains the password:

=== "Python 3.10+"

    ```Python hl_lines="24"
    {!> ../../../docs_src/response_model/tutorial003_py310.py!}
    ```

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.

So, the client sends an **HTTPS request**. This is just an HTTP request through an encrypted TLS connection.

<img src="/img/deployment/https/https04.svg">

### Decrypt the Request

The important thing is that by using standard Python types, in a single place (instead of adding more classes, decorators, etc), **FastAPI** will do a lot of the work for you.

!!! info

## Sponsor the author

You can also financially support the author (me) through <a href="https://github.com/sponsors/tiangolo" class="external-link" target="_blank">GitHub sponsors</a>.

There you could buy me a coffee ☕️ to say thanks. 😄

    The `Union` in `Union[str, None]` will allow your editor to give you better support and detect errors.

## Additional validation

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

### Import `Query` and `Annotated`

To achieve that, first import:

* `Query` from `fastapi`

* the data from the client to be sent through the network
* the data sent by your program to be received by the client through the network
* the contents of a file in the disk to be read by the system and given to your program
* the contents your program gave to the system to be written to disk

But if you are certain that the content that you are returning is **serializable with JSON**, you can pass it directly to the response class and avoid the extra overhead that FastAPI would have by passing your return content through the `jsonable_encoder` before passing it to the response class.

```Python hl_lines="2  7"
{!../../../docs_src/custom_response/tutorial001b.py!}
```

!!! info

        return item

    @app.get("/items/")
    def read_items() -> List[Item]:
        return [
            Item(
                name="Portal Gun",
                description="Device to travel through the multi-rick-verse",
                sub=SubItem(subname="subname"),
            ),
            Item(name="Plumbus"),
        ]

    client = TestClient(app)
    return client


def test_create_item():