@rob-brown said in Is there any way to use this with an existing userbase?:
If I simply implement the other side of it (i.e. make my app "pretend to be wordpress") should that do the trick? Any major gotchas I'm not thinking of?
YES! If you can get your app to act the same as WordPress here, then NodeBB could talk to it without any further ado. That would be a great approach.