#### Define a *path operation decorator*

```Python hl_lines="6"
{!../../../docs_src/first_steps/tutorial001.py!}
```

The `@app.get("/")` tells **FastAPI** that the function right below is in charge of handling requests that go to:

* the path `/`
* using a <abbr title="an HTTP GET method"><code>get</code> operation</abbr>

!!! info "`@decorator` Info"

* Add a **JSON Schema** for the response, in the OpenAPI *path operation*.
    * This will be used by the **automatic docs**.
    * It will also be used by automatic client code generation tools.

We also saw that HTTPS is normally provided by a component **external** to your application server, a **TLS Termination Proxy**.

And there has to be something in charge of **renewing the HTTPS certificates**, it could be the same component or it could be something different.

### Example Tools for HTTPS

Some of the tools you could use as a TLS Termination Proxy are:

* Traefik

```

</div>

!!! tip
    With `passlib`, you could even configure it to be able to read passwords created by **Django**, a **Flask** security plug-in or many others.

    So, you would be able to, for example, share the same data from a Django application in a database with a FastAPI application. Or gradually migrate a Django application using the same database.

```Python hl_lines="14-17" title="app/main.py"
{!../../../docs_src/bigger_applications/app/main.py!}
```

That way, the original `APIRouter` will keep unmodified, so we can still share that same `app/internal/admin.py` file with other projects in the organization.

The result is that in our app, each of the *path operations* from the `admin` module will have:

* The prefix `/admin`.
* The tag `admin`.

## Pydantic models

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> is a Python library to perform data validation.

You declare the "shape" of the data as classes with attributes.

And each attribute has a type.

This is very useful when you need to:

* Have shared logic (the same code logic again and again).
* Share database connections.
* Enforce security, authentication, role requirements, etc.
* And many other things...

All these, while minimizing code repetition.

## First Steps

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## Create a Pull Request

You can [contribute](contributing.md){.internal-link target=_blank} to the source code with Pull Requests, for example:

* To fix a typo you found on the documentation.
* To share an article, video, or podcast you created or found about FastAPI by <a href="https://github.com/tiangolo/fastapi/edit/master/docs/en/data/external_links.yml" class="external-link" target="_blank">editing this file</a>.

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