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Background tasks

This page describes how to start background tasks in request handlers, and how to configure background tasks that run periodically during the application's lifetime.

How to handle a request in background

The following example shows how to handle a web request in background, which is the use case for the HTTP 202 Accepted response status code.

import asyncio
from blacksheep import Application, Response, accepted

app = Application(show_error_details=True)
get = app.router.get

async def background_work():
    # simulate a delay...
    await asyncio.sleep(1)

def home() -> Response:
    # start a task in background

    # note: the server returns a response immediately, so before the conclusion
    # of the background task
    return accepted("Operation accepted")

How to configure background tasks

The following example shows how to configure a background tasks, including the activation of a service resolved by the DI container, running periodically once every second:

import asyncio
from datetime import datetime

from blacksheep import Application

app = Application()

def home():
    return f"Hello, World! {datetime.utcnow().isoformat()}"

def get_current_timestamp():
    return datetime.utcnow().isoformat()

class Foo:
    def __init__(self) -> None:

async def task_example(app: Application) -> None:
    # example background task, running once every second,
    # this example also shows how to activate a service using the CI container
    while True:

        my_foo = app.service_provider.get(Foo)
        assert isinstance(my_foo, Foo)
        print("Foo id: ", id(my_foo))

        await asyncio.sleep(1)

async def configure_background_tasks(app):

app.on_start += configure_background_tasks

Last modified on: 2022-02-16 07:52:42