zustand-patterns

SKILL.md

Zustand Patterns

Modern state management with Zustand 5.x - lightweight, TypeScript-first, no boilerplate.

Overview

Global state without Redux complexity

Shared state across components without prop drilling

Persisted state with localStorage/sessionStorage

Computed/derived state with selectors

State that needs middleware (logging, devtools, persistence)

Core Patterns

Covers basic stores, slices, Immer, persist, selectors, async actions, and devtools.

Load Read("${CLAUDE_SKILL_DIR}/references/core-patterns.md") for full code examples of all 7 core patterns.

Quick Reference
// ✅ Create typed store with double-call pattern
const useStore = create<State>()((set, get) => ({ ... }));

// ✅ Use selectors for all state access
const count = useStore((s) => s.count);

// ✅ Use useShallow for multiple values (Zustand 5.x)
const { a, b } = useStore(useShallow((s) => ({ a: s.a, b: s.b })));

// ✅ Middleware order: immer → subscribeWithSelector → devtools → persist
create(persist(devtools(immer((set) => ({ ... })))))

// ❌ Never destructure entire store
const store = useStore(); // Re-renders on ANY change

// ❌ Never store server state (use TanStack Query instead)
const useStore = create((set) => ({ users: [], fetchUsers: async () => ... }));

Key Decisions

Decision
Option A
Option B
Recommendation

State structure
Single store
Multiple stores
Slices in single store - easier cross-slice access

Nested updates
Spread operator
Immer middleware
Immer for deeply nested state (3+ levels)

Persistence
Manual localStorage
persist middleware
persist middleware with partialize

Multiple values
Multiple selectors
useShallow
useShallow for 2-5 related values

Server state
Zustand
TanStack Query
TanStack Query - Zustand for client-only state

DevTools
Always on
Conditional
Conditional - enabled: process.env.NODE_ENV === 'development'

Anti-Patterns & Integration

Forbidden patterns (store destructuring, derived state, server state, direct mutation) and React Query integration guidance.

Load Read("${CLAUDE_SKILL_DIR}/references/anti-patterns-and-integration.md") for anti-pattern examples and TanStack Query separation patterns.

Related Skills

tanstack-query-advanced - Server state management (use with Zustand for client state)

form-state-patterns - Form state (React Hook Form vs Zustand for forms)

react-server-components-framework - RSC hydration considerations with Zustand

Capability Details

store-creation

Keywords: zustand, create, store, typescript, state
Solves: Setting up type-safe Zustand stores with proper TypeScript inference

slices-pattern

Keywords: slices, modular, split, combine, StateCreator
Solves: Organizing large stores into maintainable, domain-specific slices

middleware-stack

Keywords: immer, persist, devtools, middleware, compose
Solves: Combining middleware in correct order for immutability, persistence, and debugging

selector-optimization

Keywords: selector, useShallow, re-render, performance, memoization
Solves: Preventing unnecessary re-renders with proper selector patterns

persistence-migration

Keywords: persist, localStorage, sessionStorage, migrate, version
Solves: Persisting state with schema migrations between versions

References

Load on demand with Read("${CLAUDE_SKILL_DIR}/references/<file>"):

File
Content

core-patterns.md
Basic store, slices, Immer, persist, selectors, async, devtools

anti-patterns-and-integration.md
Forbidden patterns and React Query integration

middleware-composition.md
Combining multiple middleware in correct order

Other resources:

Load: Read("${CLAUDE_SKILL_DIR}/scripts/store-template.ts") - Production-ready store template

Load: Read("${CLAUDE_SKILL_DIR}/checklists/zustand-checklist.md") - Implementation checklist