Clojurians Log v2

I’m working adding permissions to a websocket endpoint and I have a few questions. My goal is to filter messages based on permissions for each connection. Got that part figured out. However, so permissions don’t become stale I want to use an atom to cache permissions and on some interval refresh the cache for all current connections. So two questions, 1) is there anyway to inspect the subscribers to an event-bus? 2) if not, how can I detect a connection being closed so I don’t fetch permissions for said user when I do the cache refresh.