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Channels for communication

Why you need it​

Flows need durable messages from the outside world and between concurrent Steps.

Code examples​

Choose an SDK (preference is sticky in this browser; default Python).

unblock = Channel("unblock", str)

def wait_for(self, context, input):
    return Wait.any_of(self.unblock.for_one())

Define Channels on the Flow; wait with channel.for_one() / for_n; publish from RPC or another Step.

How Dex implements it​

Channel messages are persisted. Waiting Steps subscribe via Conditions; PublishToChannel completes matching waits.

Traditional workarounds​

Workarounds: Kafka topics + consumer offsets + correlation IDs, or DB outboxes polled by workers.