Alternatively, if you don't have a way to provide a command line option like `--root-path` or equivalent, you can set the `root_path` parameter when creating your FastAPI app:

```Python hl_lines="3"
{!../../../docs_src/behind_a_proxy/tutorial002.py!}
```

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

### About `root_path`

!!! note
    The command `uvicorn main:app` refers to:

    * `main`: the file `main.py` (the Python "module").
    * `app`: the object created inside of `main.py` with the line `app = FastAPI()`.

    It is equivalent to:

    ```Python
    from main import app
    ```

!!! warning
    Uvicorn and others support a `--reload` option that is useful during development.

And multiple processes normally **don't share any memory**. This means that each running process has its own things, variables, and memory. And if you are consuming a large amount of memory in your code, **each process** will consume an equivalent amount of memory.

### Server Memory

* Improve handling of custom classes for `Request`s and `APIRoute`s.
    * This helps to more easily solve use cases like:
        * Reading a body before and/or after a request (equivalent to a middleware).
        * Run middleware-like code only for a subset of *path operations*.
        * Process a request before passing it to a *path operation function*. E.g. decompressing, deserializing, etc.

}

my_second_user: User = User(**second_user_data)
```

!!! info
    `**second_user_data` means:

    Pass the keys and values of the `second_user_data` dict directly as key-value arguments, equivalent to: `User(id=4, name="Mary", joined="2018-11-30")`

### Editor support

* Build your FastAPI image:

<div class="termy">

```console
$ docker build -t myimage .

---> 100%
```

</div>

!!! tip
    Notice the `.` at the end, it's equivalent to `./`, it tells Docker the directory to use to build the container image.

    In this case, it's the same current directory (`.`).

### Start the Docker Container

* Run a container based on your image: