NimbleJS

Small, framework-agnostic signals and state management for TypeScript apps.

Live website · GitHub repository

NimbleJS provides signals, computed values, effects, batched updates, stores, and optional history/persistence plugins. It has no renderer and no DOM dependency in its core, so it can support vanilla JavaScript, Web Components, workers, and framework adapters.

Status: pre-1.0 and suitable for experiments. API compatibility and performance guarantees are not yet stable.

Install

npm install @onuracar-dev/nimblejs

Signals, computed values, and cleanup

import { computed, effect, signal } from '@onuracar-dev/nimblejs';

const count = signal(0);
const doubled = computed(() => count.value * 2);

const stop = effect(() => {
  console.log(`count=${count.value}, doubled=${doubled.value}`);
  return () => console.log('cleanup before the next run');
});

count.value = 2;
stop();
doubled.dispose();

Effects subscribe only to values read in their latest run. Stopping an effect removes its dependencies and executes its final cleanup once.

Batching and scheduling

batch delays notifications until its outermost callback completes and runs each affected effect once.

import { batch, effect, signal } from '@onuracar-dev/nimblejs';

const first = signal('Ada');
const last = signal('Lovelace');
effect(() => console.log(`${first.value} ${last.value}`));

batch(() => {
  first.value = 'Grace';
  last.value = 'Hopper';
});

Effects also accept a scheduler for integration with microtask, animation-frame, or host-framework queues:

effect(render, { scheduler: (run) => queueMicrotask(run) });

The scheduler owns de-duplication outside a NimbleJS batch.

Stores, persistence, and history

import { createStore, persist, withHistory } from '@onuracar-dev/nimblejs';

const settings = createStore('settings', { theme: 'dark', sidebarOpen: true });
persist(settings, { storage: globalThis.localStorage });
const history = withHistory(settings, { maxHistory: 25 });

settings.setRawState({ theme: 'light', sidebarOpen: false });
history.undo();
history.dispose();

Persistence uses JSON and application-provided Storage. It does not encrypt, validate, migrate, or synchronize state. History also uses JSON snapshots, so circular and non-serializable values are outside its supported scope.

API

| Export | Purpose | | --- | --- | | signal | Mutable reactive value with Object.is equality | | computed | Derived value with explicit dispose() | | effect | Dependency-tracked side effect with cleanup and optional scheduler | | batch | Coalesce notifications across nested synchronous writes | | createStore | Named collection of signals and batched raw-state updates | | persist | Hydrate/save a store through a Storage adapter | | withHistory | Bounded JSON-snapshot undo/redo controller |

Development

npm ci
npm test
npm run build
npm run pack:check

The architectural boundary with FluxDOM is recorded in docs/adr/0001-fluxdom-and-nimblejs-boundary.md: the projects share tested semantics but do not depend on one another.

License

MIT. Copyright 2026 Onur Acar.