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`:

```Python hl_lines="8"
{!../../../docs_src/events/tutorial001.py!}
```

```

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

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

    repo = g.get_repo(settings.github_repository)
    if not settings.github_event_path.is_file():
        raise RuntimeError(
            f"No github event file available at: {settings.github_event_path}"
        )
    contents = settings.github_event_path.read_text()
    github_event = PartialGitHubEvent.parse_raw(contents)

    # Avoid race conditions with multiple labels

from fastapi import FastAPI

app = FastAPI()


@app.on_event("shutdown")
def shutdown_event():
    with open("log.txt", mode="a") as log:
        log.write("Application shutdown")


@app.get("/items/")
async def read_items():

                    var content = document.createTextNode(event.data)
                    message.appendChild(content)
                    messages.appendChild(message)
                };
                event.preventDefault()
            }
            function sendMessage(event) {
                var input = document.getElementById("messageText")
                ws.send(input.value)

href="https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop" class="external-link" target="_blank">MongoDBs MotorClient</a>), dann denken Sie daran, Objekte zu instanziieren, die einen Event Loop nur innerhalb asynchroner Funktionen benötigen, z. B. einen `@app.on_event("startup")`-Callback....

    body: Subscription, token: Annotated[str, Security(bearer_scheme)]
):
    """
    When a new user subscribes to your service we'll send you a POST request with this
    data to the URL that you register for the event `new-subscription` in the dashboard.
    """


client = TestClient(app)


def test_dummy_webhook():
    # Just for coverage
    new_subscription(body={}, token="Bearer 123")

                    var content = document.createTextNode(event.data)
                    message.appendChild(content)
                    messages.appendChild(message)
                };
                event.preventDefault()
            }
            function sendMessage(event) {
                var input = document.getElementById("messageText")
                ws.send(input.value)

# Testing Events: startup - shutdown

When you need your event handlers (`startup` and `shutdown`) to run in your tests, you can use the `TestClient` with a `with` statement:

```Python hl_lines="9-12  20-24"
{!../../../docs_src/app_testing/tutorial003.py!}

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN