# Primeros pasos

Un archivo muy simple de FastAPI podría verse así:

```Python
{!../../../docs_src/first_steps/tutorial001.py!}
```

Copia eso a un archivo `main.py`.

Corre el servidor en vivo:

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

<img src="/img/tutorial/security/image01.png">

!!! check "Authorize button!"
    You already have a shiny new "Authorize" button.

    And your *path operation* has a little lock in the top-right corner that you can click.

And if you click it, you have a little authorization form to type a `username` and `password` (and other optional fields):

<img src="/img/tutorial/security/image02.png">

!!! note