Is there any way to get access to the underlying Headers object when using the stream library? I want to grap some values from the headers so I can use them in my logging context. I guess process! could be used?

Think that's only available using the processor API (i.e. via transform etc). However does look like something they want to expose to the DSL eventually. Probably won't hit jackdaw for a while though https://stackoverflow.com/a/46738514

Here's the issue to follow. Once this gets done, it would be possible (and relatively easy really) to add support in jackdaw. https://issues.apache.org/jira/browse/KAFKA-4125