@pogly/spacetimedb-predict

Optimistic updates and client-side prediction for SpacetimeDB clients (experimental). Call a reducer and the UI changes at once; the prediction is re-run on every server change until the reply comes back, then the real rows take over without a flicker. Refused or timed-out calls roll back.

npm install @pogly/spacetimedb-predict

import { predict } from '@pogly/spacetimedb-predict';

const p = predict({ task: { table: conn.db.task, key: (t) => t.id, autoInc: 'id' } });

await p.call(
  () => conn.reducers.toggleTask({ id }),
  (d) => {
    const t = d.task.find(id);
    if (t) d.task.update({ ...t, done: !t.done });
  }
);
p.subscribe(() => render(p.table('task').rows()));

• React: usePredicted(p, 'task') and usePredictedCall(p, send, prediction) from @pogly/spacetimedb-predict/react.
• Shared reducer logic (TypeScript modules): shimDb(draft, { task: { unique: ['id'] } }) from @pogly/spacetimedb-predict/shim gives the logic a ctx.db over the prediction.

The full README, a demo and the measurements are in the repository.