SpacetimeDB 2.0 makes the database your game server.

You run game logic “inside” the DB, model world state as tables, and expose moves/damage/spawns as reducers. Clients (like Three.js) subscribe over WebSockets and get fine‑grained diffs instead of polling, so the server stays authoritative and the client just renders and interpolates. Generous free tier, paid starts at $25/month.

https://discourse.threejs.org/t/spacetimedb-threejs-support-...