Store

The Store module manages reactive proxies for objects and arrays. It depends on Core signals and batching, but not DOM, JSX, or Async.

APIs

createStore

Create a shallow store. Only first-level properties are proxied.

JavaScript
import { createEffect, createStore } from 'vanilla-signal';const state = createStore({ count: 0, nested: { value: 1 } });createEffect(() => {  console.log(state.count);});state.count++;

createDeepStore

Create a deep store. Nested objects and arrays are lazily proxied when read.

JavaScript
import { createDeepStore } from 'vanilla-signal';const state = createDeepStore({  user: { name: 'Ada' },  items: [],});state.user.name = 'Grace';state.items.push({ id: 1 });

createReadonly

Create a deeply readonly store. Reads remain trackable, while writes, deletes, and array mutations are blocked.

JavaScript
const readonlyState = createReadonly(state);

In default mode, readonly violations print a warning and ignore the write. Strict mode throws a TypeError directly:

JavaScript
const readonlyState = createReadonly(state, { strictReadonly: true });

produce

Run mutable updates inside batch.

JavaScript
produce(state, (draft) => {  draft.user.name = 'Grace';  draft.items.push({ id: 2 });});

unwrap / snapshot

Convert store proxies into plain snapshots.

JavaScript
const data = snapshot(state);const raw = unwrap(state);

Boundaries:

• Only plain objects and arrays are processed.
• Enumerable string keys and enumerable symbol keys are copied.
• Non-enumerable keys are not included in snapshots.
• Non-proxied objects such as Date, Map, Set, and class instances are preserved as-is.
• Circular references are preserved as circular structures and do not cause recursive stack overflow.

isStore / isReadonlyStore

Check whether a value is a store proxy created by this runtime.

JavaScript
isStore(state);isReadonlyStore(readonlyState);

raw

Return the original object behind a store proxy.

JavaScript
const source = raw(state);

Mutating the raw object directly does not trigger reactive updates. raw() prints a warning once by default. If it is only used for readonly inspection, disable the warning:

JavaScript
const source = raw(state, { warn: false });

storeVersion

Read the whole-store version. When read inside an effect/memo, any field write, delete, or array-structure change will trigger a re-run.

JavaScript
createEffect(() => {  console.log(storeVersion(state));});

Proxy Boundaries

• Plain objects and arrays are proxied.
• Date, Map, Set, and class instances are not proxied.
• Writes that bypass the proxy through original object references do not trigger reactive updates.
• __raw, __isStore, and __version__ are no longer public contracts. Use raw, isStore, and storeVersion instead.