Quick Start¶

1. Start a broker¶

Valkey/Redis:

docker run -d -p 6379:6379 valkey/valkey:8

Or RabbitMQ:

docker run -d -p 5672:5672 -p 15672:15672 rabbitmq:4-management

2. Create your app¶

# celeryapp.py
from celery import Celery

app = Celery("myapp")
app.config_from_object({
    "broker_url": "redis://localhost:6379/0",
    "result_backend": "redis://localhost:6379/1",
    "include": ["tasks"],
})

3. Define tasks¶

# tasks.py
import asyncio
from celeryapp import app

@app.task
def add(x, y):
    return x + y

@app.task
async def slow_add(x, y):
    await asyncio.sleep(1)
    return x + y

Sync tasks (add) run in a thread pool. Async tasks (slow_add) run directly on the asyncio event loop.

4. Start the worker¶

PYTHONPATH=. celery -A celeryapp worker --loglevel=info -E

The -E flag enables events for monitoring with Flower.

5. Send tasks¶

from tasks import add, slow_add

# Fire and forget
add.delay(2, 3)

# With options
add.apply_async(args=(2, 3), countdown=10)

# Async task
slow_add.delay(10, 20)

6. Monitor with Flower (optional)¶

pip install flower
celery -A celeryapp flower

Open http://localhost:5555 to see workers, tasks, and live graphs.

Using RabbitMQ¶

Same setup, just change the broker URL:

app.config_from_object({
    "broker_url": "amqp://guest:guest@localhost:5672//",
    "result_backend": "redis://localhost:6379/1",
    "include": ["tasks"],
})

The AMQP transport uses aio-pika under the hood. Install it with:

uv add aio-pika