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