É apenas uma função padrão que pode receber parâmetros.

Pode ser uma função `async def` ou `def` normal, o **FastAPI** saberá como lidar com isso corretamente.

Nesse caso, a função de tarefa gravará em um arquivo (simulando o envio de um e-mail).

E como a operação de gravação não usa `async` e `await`, definimos a função com `def` normal:

```Python hl_lines="6-9"
{!../../docs_src/background_tasks/tutorial001.py!}
```

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Add the background task

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_main():

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def root():

def get_name_with_age(name: str, age: int):
    name_with_age = name + " is this old: " + str(age)

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/{item_id}")
async def read_item(item_id: int):

def say_hi(name: str | None = None):
    if name is not None:
        print(f"Hey {name}!")
    else:

def get_full_name(first_name: str, last_name: str):
    full_name = first_name.title() + " " + last_name.title()
    return full_name

from typing_extensions import Annotated


def say_hello(name: Annotated[str, "this is just metadata"]) -> str:

from typing import Annotated


def say_hello(name: Annotated[str, "this is just metadata"]) -> str: