# Background Tasks - `BackgroundTasks`

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```

## `BackgroundTasks` verwenden

Importieren Sie zunächst `BackgroundTasks` und definieren Sie einen Parameter in Ihrer *Pfadoperation-Funktion* mit der Typdeklaration `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

**FastAPI** erstellt für Sie das Objekt vom Typ `BackgroundTasks` und übergibt es als diesen Parameter.

from typing import Annotated

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: str | None = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q

## Usando `BackgroundTasks`

Primeiro, importe `BackgroundTasks` e defina um parâmetro em sua _função de operação de caminho_ com uma declaração de tipo de `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

O **FastAPI** criará o objeto do tipo `BackgroundTasks` para você e o passará como esse parâmetro.

## Using `BackgroundTasks`

First, import `BackgroundTasks` and define a parameter in your *path operation function* with a type declaration of `BackgroundTasks`:

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** will create the object of type `BackgroundTasks` for you and pass it as that parameter.

## Create a task function

from typing import Any, Callable

from starlette.background import BackgroundTasks as StarletteBackgroundTasks
from typing_extensions import Annotated, Doc, ParamSpec

P = ParamSpec("P")


class BackgroundTasks(StarletteBackgroundTasks):
    """
    A collection of background tasks that will be called after a response has been
    sent to the client.

    Read more about it in the

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: str | None = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q


@app.post("/send-notification/{email}")

## Использование класса `BackgroundTasks`

Сначала импортируйте `BackgroundTasks`, потом добавьте в функцию параметр с типом `BackgroundTasks`:

```Python hl_lines="1  13"
{!../../docs_src/background_tasks/tutorial001.py!}
```

**FastAPI** создаст объект класса `BackgroundTasks` для вас и запишет его в параметр.

## Создание функции для фоновой задачи

## Utiliser `BackgroundTasks`

Pour commencer, importez `BackgroundTasks` et définissez un paramètre dans votre *fonction de chemin* avec `BackgroundTasks` comme type déclaré.

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** créera l'objet de type `BackgroundTasks` pour vous et le passera comme paramètre.

## Créer une fonction de tâche

from typing import Union

from fastapi import BackgroundTasks, Depends, FastAPI

app = FastAPI()


def write_log(message: str):
    with open("log.txt", mode="a") as log:
        log.write(message)


def get_query(background_tasks: BackgroundTasks, q: Union[str, None] = None):
    if q:
        message = f"found query: {q}\n"
        background_tasks.add_task(write_log, message)
    return q