Ele tem:

* Performance seriamente impressionante.
* Suporte a WebSocket.
* Suporte a GraphQL.
* Tarefas de processamento interno por trás dos panos.
* Eventos de inicialização e encerramento.
* Cliente de testes construído com HTTPX.
* Respostas CORS, GZip, Arquivos Estáticos, Streaming.
* Suporte para Sessão e Cookie.
* 100% coberto por testes.

Tiene:

* Un rendimiento seriamente impresionante.
* Soporte para WebSocket.
* Tareas en segundo plano dentro del proceso.
* Eventos de inicio y apagado.
* Cliente de pruebas basado en HTTPX.
* CORS, GZip, Archivos estáticos, Responses en streaming.
* Soporte para sesiones y cookies.
* Cobertura de tests del 100%.
* Base de código 100% tipada.

```Dockerfile
# ⛔️ No hagas esto
CMD fastapi run app/main.py --port 80
```

Asegúrate de siempre usar la **forma exec** para garantizar que FastAPI pueda cerrarse de manera adecuada y que [los eventos de lifespan](../advanced/events.md){.internal-link target=_blank} sean disparados.

 *
 * <p>To post an event, simply provide the event object to the {@link #post(Object)} method. The
 * EventBus instance will determine the type of event and route it to all registered listeners.
 *
 * <p>Events are routed based on their type &mdash; an event will be delivered to any subscriber for
 * any type to which the event is assignable. This includes implemented interfaces, all

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event { #shutdown-event }

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

        // Create different implementations
        SearchLogEvent event1 = new TestSearchLogEvent("id1", 1L, "type1");
        SearchLogEvent event2 = new NullSearchLogEvent();
        SearchLogEvent event3 = new EmptySearchLogEvent();

        // Test polymorphic behavior
        SearchLogEvent[] events = { event1, event2, event3 };

        for (SearchLogEvent event : events) {
            // All methods should be callable without exceptions

![Events Diagram](../assets/images/events@2x.png)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java

Diese Funktionen können mit `async def` oder normalem `def` deklariert werden.

### `startup`-Event

Um eine Funktion hinzuzufügen, die vor dem Start der Anwendung ausgeführt werden soll, deklarieren Sie diese mit dem Event `startup`:

{* ../../docs_src/events/tutorial001.py hl[8] *}

events@2x.png...

# Testing Events: lifespan and startup - shutdown { #testing-events-lifespan-and-startup-shutdown }

When you need `lifespan` to run in your tests, you can use the `TestClient` with a `with` statement:

{* ../../docs_src/app_testing/tutorial004.py hl[9:15,18,27:28,30:32,41:43] *}


You can read more details about the ["Running lifespan in tests in the official Starlette documentation site."](https://www.starlette.io/lifespan/#running-lifespan-in-tests)