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name: React State Management description: Standards for managing local, global, and server state. metadata: labels: [react, state, redux, zustand, context] triggers: files: ['/*.tsx', '/*.jsx'] keywords: [state, useReducer, context, store, props]

React State Management

Priority: P0 (CRITICAL)

Choosing the right tool for state scope.

Implementation Guidelines

• Local: useState. useReducer if complex (state machine).
• Derived: const fullName = first + last. No state sync.
• Context: DI, Theming, Auth. Not for high-freq data.
• Global: Zustand/Redux for app-wide complex flow.
• Server Cache: Use React.cache (RSC) to dedupe requests per render.
• Server State: React Query / SWR / Apollo. Cache != UI State.
• URL: Store filter/sort params in URL (Source of Truth).
• Immutability: Never mutate. Use spread or Immer.

Anti-Patterns

• No Prop Drilling > 2: Use Context/Composition.
• No Mirroring Refs: Don't copy props to state.
• No Multi-Source: Single Source of Truth.
• No Context Abuse: Context causes full-tree re-render.

Reference & Examples

For Zustand, Redux Toolkit, and TanStack Query patterns: See references/REFERENCE.md.

Related Topics

hooks | component-patterns | performance