TanStack Store
Overview
TanStack Store is a lightweight, framework-agnostic reactive state management library with type-safe updates, derived computations, batched mutations, and effect management. It powers the core of TanStack libraries internally and can be used as a standalone state solution. Framework adapters are available for React, Vue, Solid, Angular, and Svelte.
Core primitives:
- Store — reactive container with
setState, subscriptions, and lifecycle hooks - Derived — lazily computed values that track Store/Derived dependencies
- Effect — side-effect runner triggered by dependency changes
- batch — groups multiple updates so subscribers fire once
When to use: Shared reactive state across components, derived/computed values from multiple stores, batched state updates, framework-agnostic state logic reusable across React/Vue/Solid/Angular/Svelte, lightweight alternative to Redux/Zustand/MobX.
When NOT to use: Server state and caching (TanStack Query), complex normalized state with middleware (Redux Toolkit), form state management (TanStack Form), simple component-local state (useState/useSignal).
Key characteristics:
- Tiny bundle size with zero dependencies
- Immutable update model (always return new references from
setState) - Lazy evaluation for Derived values (recompute only when accessed after change)
- Explicit mount/unmount lifecycle for Derived and Effect (no automatic cleanup)
Installation
| Package | Use Case |
|---|---|
@tanstack/store | Framework-agnostic core |
@tanstack/react-store | React adapter (re-exports core) |
@tanstack/vue-store | Vue adapter |
@tanstack/solid-store | Solid adapter |
@tanstack/angular-store | Angular adapter |
@tanstack/svelte-store | Svelte adapter |
Framework packages re-export the core Store, Derived, Effect, and batch — install only the framework package, not both.
Quick Reference
| Pattern | API | Key Points |
|---|---|---|
| Create store | new Store(initialState, options?) | Generic over TState and TUpdater |
| Read state | store.state | Synchronous property access |
| Previous state | store.prevState | Value before last setState call |
| Update state | store.setState((prev) => newState) | Accepts updater function or direct value |
| Subscribe | store.subscribe(listener) | Returns unsubscribe function |
| Derived value | new Derived({deps, fn}) | Lazily recomputes when dependencies change |
| Mount derived | derived.mount() | Required to activate dependency tracking |
| Derived from derived | Nest Derived in another deps | Forms a computation graph |
| Batch updates | batch(() => {...}) | Subscribers notified once after all updates |
| Side effects | new Effect({deps, fn, eager?}) | Runs fn when dependencies change |
| Mount effect | effect.mount() | Required to start listening |
| React binding | useStore(store, selector?) | Re-renders only when selected value changes |
| Shallow compare | useStore(store, selector, shallow) | Prevents re-renders for structurally equal objects |
| Lifecycle: subscribe | onSubscribe option | Fires on first subscriber, cleanup on last |
| Lifecycle: update | onUpdate option | Fires after every state change |
| Custom updater | updateFn option | Replace default setState behavior |
| Previous deps | fn: ({prevDepVals}) | Compare current vs previous dependency values |
| Dep vals access | fn: ({currDepVals}) | Array ordered by deps declaration order |
Common Mistakes
| Mistake | Correct Pattern |
|---|---|
Reading derived.state without mounting | Call derived.mount() before accessing state |
| Forgetting to unmount derived/effect | Store the cleanup function and call it on teardown |
Multiple setState calls without batching | Wrap related updates in batch() to avoid intermediate recomputation |
Selecting objects in useStore without shallow | Pass shallow as third argument to prevent unnecessary re-renders |
| Mutating state object directly | Always return a new object from setState updater |
| Subscribing inside render without cleanup | Use useStore hook in React instead of manual subscribe |
| Creating stores inside React components | Instantiate stores outside components or in a ref/useState |
| Not including all deps in Derived | List every Store/Derived dependency in the deps array |
| Mounting Derived deps after the parent | Mount leaf dependencies before parent Derived values |
Using @tanstack/store with React directly | Install @tanstack/react-store which re-exports core |
Delegation
- Server state and caching: Delegate to the
tanstack-queryskill if available. Otherwise, recommend:npx skills add oakoss/agent-skills --skill tanstack-query - React component patterns: Delegate to framework-specific skills for component architecture
- Form state management: Delegate to the
tanstack-formskill if available. Otherwise, recommend:npx skills add oakoss/agent-skills --skill tanstack-form - Query pattern discovery: Use
Exploreagent to find examples in the codebase - Code review: Delegate to
code-revieweragent for store architecture review