## Global Dependencies

It will:

* Return that status code in the response.
* Document it as such in the OpenAPI schema (and so, in the user interfaces):

<img src="/img/tutorial/response-status-code/image01.png">

!!! note
    Some response codes (see the next section) indicate that the response does not have a body.

    FastAPI knows this, and will produce OpenAPI docs that state there is no response body.

    'email': '******@****.***',
    'full_name': None,
}
```

#### Unwrapping a `dict`

If we take a `dict` like `user_dict` and pass it to a function (or class) with `**user_dict`, Python will "unwrap" it. It will pass the keys and values of the `user_dict` directly as key-value arguments.

So, continuing with the `user_dict` from above, writing:

```Python
UserInDB(**user_dict)
```

You are encouraged to [write tests](https://fastapi.tiangolo.com/tutorial/testing/) for your application and update your FastAPI version frequently after ensuring that your tests are passing. This way you will benefit from the latest features, bug fixes, and **security fixes**.

You can learn more about [FastAPI versions and how to pin and upgrade them](https://fastapi.tiangolo.com/deployment/versions/) for your project in the docs.

`FastAPI` is actually a sub-class of `Starlette`. So, if you already know or use Starlette, most of the functionality will work the same way.

With **FastAPI** you get all of **Starlette**'s features (as FastAPI is just Starlette on steroids):

Then one the last requests that wait less seconds will try to open a database connection, but as one of those previous requests for the other tabs will probably be handled in the same thread as the first one, it will have the same database connection that is already open, and Peewee will throw an error and you will see it in the terminal, and the response will have an `Internal Server Error`.

This will probably happen for more than one of those tabs.

                    "description": 'Create an invoice.\n\nThis will (let\'s imagine) let the API user (some external developer) create an\ninvoice.\n\nAnd this path operation will:\n\n* Send the invoice to the client.\n* Collect the money from the client.\n* Send a notification back to the API user (the external developer), as a callback.\n    * At this point is that the API will somehow send a POST request to the\n        external API with the notification of the invoice...

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

!!! info
    The parameter `response_class` will also be used to define the "media type" of the response.

    In this case, the HTTP header `Content-Type` will be set to `application/json`.

    And it will be documented as such in OpenAPI.

!!! tip
    The `ORJSONResponse` is currently only available in FastAPI, not in Starlette.

        * In requests, a list will be read, eliminating duplicates and converting it to a `set`.
        * In responses, the `set` will be converted to a `list`.
        * The generated schema will specify that the `set` values are unique (using JSON Schema's `uniqueItems`).
* `bytes`:
    * Standard Python `bytes`.
    * In requests and responses will be treated as `str`.

            Optional[str],
            Doc(
                """
                The URL where the OpenAPI schema will be served from.

                If you set it to `None`, no OpenAPI schema will be served publicly, and
                the default automatic endpoints `/docs` and `/redoc` will also be
                disabled.

                Read more in the