Seems like it requires a datomic pro subscription to run it. Interesting they opted for a paid datastore as a backend to this, so you get the cons of having to subscribe to this but then also run redis and the UI yourself. Could be interesting to see a data store you could run yourself to back this up in the roadmap but seems they're focussing on the UI/UX.

Since the UI/UX is the biggest innovation here, I somewhat understand the decision but I'm sure it'll limit adoption by the majority of people that want to host their own chat platform.