Hi, is there a way to know which topic a message came from when building a topology with multiple inputs?

Only if you break out of the DSL and use the processor API. That gives you access to all the record metadata like topic-name, timestamp, partition etc.

Okay, thanks

Would it be possible for the record metadata to be obtained from Kafka, and added as Clojure metadata to the message? I don't have enough (actually any) experience with Kafka or jackdaw to know if that is a bad/infeasible idea.