Not supported yet. Full pubsub was on the plate at one point, but has yet to be supported either.
If you do implement PEP, we would love it if you would consider contributing it back to the source.
There are plenty of extension examples in the source code, you can look at them for reference on how to begin implementation.
Let me know if you have any specific questions.
Great - thanks for the help. First off, since PEP relies on CAPS, I'm implementing CAPS first. My first question regarding CAPS is what is the best way for my extension to listen for incoming IQ events. I couldn't find an example in the existing extensions. In the case of CAPS, it wouldn't be through registering a callback, since it's not purely request/response. That is, a CAPS request could come in as an IQ event:
So, what is the recommended way to listen for such an event.