for key, value in build_config.items():
        context.config.build_config[key] = value
    # Get main dependencies
    dependencies: List[str] = metadata.get("dependencies", [])
    # Add optional dependencies to the default dependencies for this (non-slim) package
    for include_optional in include_optional_dependencies:
        optional_dependencies_group = optional_dependencies.get(include_optional, [])

Right as we wanted it. ✔️

This is because FastAPI uses this `root_path` to create the default `server` in OpenAPI with the URL provided by `root_path`.

## Additional servers

!!! warning
    This is a more advanced use case. Feel free to skip it.

By default, **FastAPI** will create a `server` in the OpenAPI schema with the URL for the `root_path`.

The main thing you need to run a **FastAPI** application (or any other ASGI application) in a remote server machine is an ASGI server program like **Uvicorn**, this is the one that comes by default in the `fastapi` command.

There are several alternatives, including:

* <a href="https://www.uvicorn.org/" class="external-link" target="_blank">Uvicorn</a>: a high performance ASGI server.

@app.get("/items/{item_id}")
def main(
    item_id: int = Path(default=..., gt=0),
    query: str = Query(default=..., max_length=10),
    session: str = Cookie(default=..., min_length=3),
    x_trace: str = Header(default=..., title="Tracing header"),
):
    return {"message": "Hello World"}
```

...all these parameters are required because the default value is `...` (Ellipsis).

## `fastapi dev`

When you run `fastapi dev`, it will run on development mode.

By default, it will have **auto-reload** enabled, so it will automatically reload the server when you make changes to your code. This is resource intensive and could be less stable than without it, you should only use it for development.

### Automatic docs

Interactive API documentation and exploration web user interfaces. As the framework is based on OpenAPI, there are multiple options, 2 included by default.

* <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank"><strong>Swagger UI</strong></a>, with interactive exploration, call and test your API directly from the browser.

site_url: https://fastapi.tiangolo.com/
theme:
  name: material
  custom_dir: ../en/overrides
  palette:
  - media: '(prefers-color-scheme: light)'
    scheme: default
    primary: teal
    accent: amber
    toggle:
      icon: material/lightbulb
      name: Switch to dark mode
  - media: '(prefers-color-scheme: dark)'
    scheme: slate
    primary: teal
    accent: amber

The command `fastapi dev` reads your `main.py` file, detects the **FastAPI** app in it, and starts a server using <a href="https://www.uvicorn.org" class="external-link" target="_blank">Uvicorn</a>.

By default, `fastapi dev` will start with auto-reload enabled for local development.

You can read more about it in the <a href="https://fastapi.tiangolo.com/fastapi-cli/" target="_blank">FastAPI CLI docs</a>.

</details>

    If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

Then you could call that Python program:

<div class="termy">

```console
// Here we don't set the env var yet
$ python main.py

// As we didn't set the env var, we get the default value

Hello World from Python

The first step is to install FastAPI:

<div class="termy">

```console
$ pip install fastapi

---> 100%
```

</div>

!!! note
    When you install with `pip install fastapi` it comes with some default optional standard dependencies.

    If you don't want to have those optional dependencies, you can instead install `pip install fastapi-slim`.

## Advanced User Guide