* There can be **multiple processes** of the **same program** running at the same time.

If you check out the "task manager" or "system monitor" (or similar tools) in your operating system, you will be able to see many of those processes running.

## Testing locally with Traefik

* Add note to docs: [Include the same router multiple times with different `prefix`](https://fastapi.tiangolo.com/tutorial/bigger-applications/#include-the-same-router-multiple-times-with-different-prefix). PR [#348](https://github.com/tiangolo/fastapi/pull/348).

* Fix OpenAPI/JSON Schema generation for two functions with the same name (in different modules) with the same composite bodies.

```Python hl_lines="9-13  36-53"
{!../../../docs_src/openapi_webhooks/tutorial001.py!}
```

The webhooks that you define will end up in the **OpenAPI** schema and the automatic **docs UI**.

!!! info

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

This also means that in many cases you can pass the same object you get from a request **directly to the database**, as everything is validated automatically.

The same applies the other way around, in many cases you can just pass the object you get from the database **directly to the client**.

<img src="/img/tutorial/websockets/image04.png">

And all of them will use the same WebSocket connection.

## Using `Depends` and others

In WebSocket endpoints you can import from `fastapi` and use:

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

They work the same way as for other FastAPI endpoints/*path operations*:

=== "Python 3.10+"

    return {"Hello": "World"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

**Nota**:

Se você não sabe, verifique a seção _"In a hurry?"_ sobre <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` e `await` nas docs</a>.

</details>

### Rode

Rode o servidor com:

## `fastapi-slim`

If you don't want the extra standard optional dependencies, install `fastapi-slim` instead.

When you install with:

```bash
pip install fastapi
```

...it includes the same code and dependencies as:

```bash
pip install "fastapi-slim[standard]"
```

The standard extra dependencies are the ones mentioned above.

## License