Multiple brokers

[pabloillumina]

Hi I am interested in consuming from one broker and publishing to a different one.

Here is what i'd like to do:

import asyncio

from faststream.rabbit import RabbitBroker
from faststream.kafka import KafkaBroker
from faststream import FastStream, Logger

input_broker = KafkaBroker("localhost:9092")
output_broker = RabbitBroker("amqp://localhost:5672")

@output_broker.publisher("output_data")
@input_broker.subscriber("input_data")
async def on_input_data(msg, logger: Logger):
    logger.info(msg)
    return msg

async def main():
    app = FastStream(input_broker)
    await app.run()

if __name__ == "__main__":
    asyncio.run(main())

However, the above code fails with AssertionError: Please, connect() the broker first. from .venv/lib/python3.13/site-packages/faststream/rabbit/publisher/usecase.py", line 258, in publish

By changing the body of the function to:

@input_broker.subscriber("input_data")
async def on_input_data(msg, logger: Logger):
    logger.info(msg)
    async with output_broker:
        await output_broker.publish(msg)

it works, but looks less smooth than the first implementation.

Will FastStream allow multiple brokers? e.g. app = FastStream([input_broker, output_broker])

[Lancetnik]

@pabloillumina not yet, but it is in roadmap – #526

In 0.6 version multiple brokers in the same runtime should works fine, but we didn't test all cases

[Lancetnik]

At this point I can suggest u to just start additional broker in application lifespan

[pabloillumina]

Thank you :)