Write your logic. Deploy one binary. Every client syncs in real-time.
No app server. No pub/sub. No glue code.
Your business logic executes where your data lives. No API layer, no serialization overhead, no cold starts.
Changes propagate to every connected client in milliseconds. No message broker, no fanout service, no polling.
Tables, indexes, and row-level security defined in code. Deploy and your schema is live. No migration files.
One $5/mo VPS. One process. Zero ops.
Figma-style multiplayer. Every cursor, every keystroke syncs instantly. Incremental subscriptions mean zero wasted bandwidth.
Server-authoritative game state. Players see only what RLS allows. Reducer logic runs inside the database — no separate game server.
Typing indicators to message history. All from SQL subscriptions. No WebSocket plumbing, no Redis pub/sub.
Aggregate queries update incrementally. No polling, no timers. Your dashboard reacts to every database change in real time.
#[table(name = "messages", public)]
pub struct Message {
#[primary_key] #[auto_inc]
pub id: u64,
pub sender: Identity,
pub text: String,
}#[reducer]
fn send(text: String) {
let sender = caller_identity();
db::insert(Message { sender, text });
}const db = new Cosmictron("my-app");
db.subscribe("SELECT * FROM messages");
db.on("messages", ({ inserts }) => {
inserts.forEach(m => render(m));
});DBSP circuits compute only what changed. Not the full query — just the delta. Join 3 tables with an aggregate? Only the affected rows recompute. Your users feel instant because it is instant.
Row-level security policies are SQL predicates, auto-injected into every query and every subscription. It's not opt-in — it's structural. You literally cannot serve data a user shouldn't see.
MIT and Apache 2.0. Not BSL, not SSPL, not 'source-available.' Self-host on your $5 VPS or your enterprise cluster. No egress fees. No surprise bills. Your data never touches our servers.
Full V8 runtime — not TypeScript compiled to WASM. Use any npm package. Write async code. Call external APIs. The TypeScript you already know, running inside your database.
Benchmarked on a single node. No caching tricks. Reproducible.
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