For simplicity, I think you could change "…/" + user_id in most URLs with "…/me".
That would eliminate some parameters and also lines of code like this in room.mark_channel_as_read because server is used for nothing else:
server = wee_matter.server.get_server_from_buffer(buffer)
Great idea. I really got no incentive to do it now but it is nice to keep in mind for future developments.