React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.
Applies Vercel's performance optimization guidelines for React and Next.js code.
npx claudepluginhub secondsky/claude-skillsThis skill inherits all available tools. When active, it can use any tool Claude has access to.
AGENTS.mdREADME.mdmetadata.jsonrules/_sections.mdrules/_template.mdrules/advanced-event-handler-refs.mdrules/advanced-init-once.mdrules/advanced-use-latest.mdrules/async-api-routes.mdrules/async-defer-await.mdrules/async-dependencies.mdrules/async-parallel.mdrules/async-suspense-boundaries.mdrules/bundle-barrel-imports.mdrules/bundle-conditional.mdrules/bundle-defer-third-party.mdrules/bundle-dynamic-imports.mdrules/bundle-preload.mdrules/client-event-listeners.mdrules/client-localstorage-schema.mdComprehensive performance optimization guide for React and Next.js applications, maintained by Vercel. Contains 57 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation.
Reference these guidelines when:
| Priority | Category | Impact | Prefix |
|---|---|---|---|
| 1 | Eliminating Waterfalls | CRITICAL | async- |
| 2 | Bundle Size Optimization | CRITICAL | bundle- |
| 3 | Server-Side Performance | HIGH | server- |
| 4 | Client-Side Data Fetching | MEDIUM-HIGH | client- |
| 5 | Re-render Optimization | MEDIUM | rerender- |
| 6 | Rendering Performance | MEDIUM | rendering- |
| 7 | JavaScript Performance | LOW-MEDIUM | js- |
| 8 | Advanced Patterns | LOW | advanced- |
async-defer-await - Move await into branches where actually usedasync-parallel - Use Promise.all() for independent operationsasync-dependencies - Use better-all for partial dependenciesasync-api-routes - Start promises early, await late in API routesasync-suspense-boundaries - Use Suspense to stream contentbundle-barrel-imports - Import directly, avoid barrel filesbundle-dynamic-imports - Use next/dynamic for heavy componentsbundle-defer-third-party - Load analytics/logging after hydrationbundle-conditional - Load modules only when feature is activatedbundle-preload - Preload on hover/focus for perceived speedserver-cache-react - Use React.cache() for per-request deduplicationserver-cache-lru - Use LRU cache for cross-request cachingserver-serialization - Minimize data passed to client componentsserver-parallel-fetching - Restructure components to parallelize fetchesserver-after-nonblocking - Use after() for non-blocking operationsserver-auth-actions - Authenticate server actions like API routesserver-dedup-props - Avoid duplicate serialization in RSC propsclient-swr-dedup - Use SWR for automatic request deduplicationclient-event-listeners - Deduplicate global event listenersrerender-defer-reads - Don't subscribe to state only used in callbacksrerender-memo - Extract expensive work into memoized componentsrerender-dependencies - Use primitive dependencies in effectsrerender-derived-state - Subscribe to derived booleans, not raw valuesrerender-functional-setstate - Use functional setState for stable callbacksrerender-lazy-state-init - Pass function to useState for expensive valuesrerender-transitions - Use startTransition for non-urgent updatesrerender-memo-with-default-value - Hoist default non-primitive propsrerender-derived-state-no-effect - Derive state during render, not effectsrerender-simple-expression-in-memo - Avoid memo for simple primitivesrerender-move-effect-to-event - Put interaction logic in event handlersrerender-use-ref-transient-values - Use refs for transient frequent valuesrendering-animate-svg-wrapper - Animate div wrapper, not SVG elementrendering-content-visibility - Use content-visibility for long listsrendering-hoist-jsx - Extract static JSX outside componentsrendering-svg-precision - Reduce SVG coordinate precisionrendering-hydration-no-flicker - Use inline script for client-only datarendering-activity - Use Activity component for show/hiderendering-conditional-render - Use ternary, not && for conditionalsrendering-hydration-suppress-warning - Suppress expected mismatchesrendering-usetransition-loading - Prefer useTransition for loading statejs-batch-dom-css - Group CSS changes via classes or cssTextjs-index-maps - Build Map for repeated lookupsjs-cache-property-access - Cache object properties in loopsjs-cache-function-results - Cache function results in module-level Mapjs-cache-storage - Cache localStorage/sessionStorage readsjs-combine-iterations - Combine multiple filter/map into one loopjs-length-check-first - Check array length before expensive comparisonjs-early-exit - Return early from functionsjs-hoist-regexp - Hoist RegExp creation outside loopsjs-min-max-loop - Use loop for min/max instead of sortjs-set-map-lookups - Use Set/Map for O(1) lookupsjs-tosorted-immutable - Use toSorted() for immutabilityadvanced-event-handler-refs - Store event handlers in refsadvanced-use-latest - useLatest for stable callback refsadvanced-init-once - Initialize app once per app loadRead individual rule files for detailed explanations and code examples:
rules/async-parallel.md
rules/bundle-barrel-imports.md
rules/_sections.md
Each rule file contains:
For the complete guide with all rules expanded: AGENTS.md
Activates when the user asks about AI prompts, needs prompt templates, wants to search for prompts, or mentions prompts.chat. Use for discovering, retrieving, and improving prompts.
Search, retrieve, and install Agent Skills from the prompts.chat registry using MCP tools. Use when the user asks to find skills, browse skill catalogs, install a skill for Claude, or extend Claude's capabilities with reusable AI agent components.
This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.