KIP-42 — Add Producer and Consumer Interceptors

Accepted Client

Introduces ProducerInterceptor and ConsumerInterceptor plugin interfaces that are invoked before send and after poll respectively, enabling cross-cutting concerns (tracing, monitoring, header injection) to be applied without modifying application code. Before this, end-to-end message-level observability required modifying every application individually, which was impractical for shared infrastructure.

Details