I've been exploring Chatto as a self-hosted chat UI in my homelab for interfacing with durable agents and it works pretty well so far, although the API is (by the author's own admission) not fully stable yet.
Yes I am running it now, it is pretty nice though custom, not related to the original developer, mobile application, have few annoying problems. I.e. it does not allow you to connect to your own server right away. It does not have notifications working on stable version. I had to ask an agent to do some changes first before it was usable.
On the other hand Strafe does not have it at all, so it is not really a competition.