@vielzeug/ledger

Serialized reversible command history with cancellation ownership and atomic reactive state.

Features

• Reversible commands — every recorded command has apply() and revert()
• Atomic state — one Readable<LedgerState> for queue and history observation
• Composition — compose() combines reversible commands into one history entry
• Cancellation — queued cancelled work never starts; active work receives AbortSignal
• Idle ownership — whenIdle() waits for queued and active work to settle
• History cap — non-negative safe-integer retained depth

Install

pnpm add @vielzeug/ledger

Quick Start

Submit reversible state transitions and dispose the owner at teardown.

import { createLedger } from '@vielzeug/ledger';

let value = 'before';
const ledger = createLedger();

await ledger.do({
  apply: () => { value = 'after'; },
  label: 'Rename value',
  revert: () => { value = 'before'; },
});

await ledger.undo();
console.log(ledger.state.value.undo.length); // 0
ledger.dispose();

Keep irreversible side effects outside Ledger commands. Catch operation failures at your application boundary.

Full documentation