Help - Not Receiving Acknowledgment When Publishing to NATS JetStream’s Subject in FastStream

[Atanusaha143]

I am working with FastStream and trying to publish messages to a NATS JetStream, but I’m not seeing any acknowledgment data returned when I attempt to publish. Below is the code snippet I’m using:

class TestPublisher(ABCPublisher):
    def __init__(self, logger: Logger = Depends(Logger)):
        self._logger = logger
        self._broker = NatsBroker("nats://localhost:4222")

    async def publish(self, stream: str, subject: str, message: dict):
        async with self._broker:
            try:
                ack = await self._broker.publish(stream=stream, subject=subject, message=message)
                print(ack)  # This prints 'None'
            except Exception as e:
                self._logger.error(f"Failed to publish message: {e}")

I expected ack to contain some acknowledgment details (e.g., a confirmation that the message was successfully stored in the stream). However, the output is None, which makes it unclear if the message was acknowledged or stored.

Questions:

1. Is there a way to retrieve acknowledgment details (like sequence ID or confirmation status) after publishing a message to a NATS JetStream subject?
2. Does FastStream provide this capability for NATS JetStream, or do I need additional configuration to enable it?

Any insights or suggestions would be greatly appreciated. Thank you!

[Lancetnik]

@Atanusaha143 sorry, now we have a some architecture mistakes and we lost this functional - https://github.com/airtai/faststream/blob/main/faststream/nats/publisher/producer.py#L80

The problem related to publish(..., rpc=True) option and we just can't return something from publish method due it could return RPC response later. On 0.6.0 we removed old rpc functional to prior to request usage and we can return confirmation frame from publish method, there is no problem

[Atanusaha143]

@Lancetnik So, we are getting this functionality on an upcoming version. Right?

[Lancetnik]

@Lancetnik So, we are getting this functionality on an upcoming version. Right?

Yes

[Lancetnik]

Should be merged with #1779 - it is already in the branch