Clojurians Log v2

I've made a conditions+restarts library for clojure, and I want to implement an interactive debugger like Common Lisp's. I have a basic one that just reads from stdin to get what it needs, but I know nREPL provides me with a way that I could do something better. Is there a good place to start in the documentation for writing some code that will ask the nrepl client for some forms to evaluate and to send the client some objects, like exceptions, so that I can make an emacs package to interact with it?

I'm guessing this would be a middleware