Development

Modern TypeScript/JavaScript testing with Vitest. Fast unit and integration tests, native ESM support, Vite-powered HMR, and comprehensive mocking. Use for testing TS/JS projects.

Ultracite multi-provider linting/formatting (Biome, ESLint, Oxlint). Use for v6/v7 setup, provider selection, Git hooks, MCP integration, AI hooks, migrations, or encountering configuration, type-aware linting, monorepo errors.

Turborepo monorepo build system guidance. Triggers on: turbo.json, task pipelines, dependsOn, caching, remote cache, the "turbo" CLI, --filter, --affected, CI optimization, environment variables, internal packages, monorepo structure/best practices, and boundaries. Use when user: configures tasks/workflows/pipelines, creates packages, sets up monorepo, shares code between apps, runs changed/affected packages, debugs cache, or has apps/packages directories.

AI-powered generative UI with Thesys - create React components from natural language.

Detect test smells, overmocking, flaky tests, and coverage issues. Analyze test effectiveness, maintainability, and reliability. Use when reviewing tests or improving test quality.

TanStack Table v8 headless data tables with server-side features for Cloudflare Workers + D1. Use for pagination, filtering, sorting, virtualization, or encountering state management, TanStack Query coordination, URL sync errors.

TanStack Start (RC) full-stack React with server functions, SSR, Cloudflare Workers. Use for Next.js migration, edge rendering, or encountering hydration, auth, data pattern errors.

TanStack Router type-safe file-based routing for React. Use for SPAs, TanStack Query integration, Cloudflare Workers, or encountering devtools, type safety, loader, Vite bundling errors.

TanStack Query v5 (React Query) server state management. Use for data fetching, caching, mutations, or encountering v4 migration, stale data, invalidation errors.

TanStack AI (alpha) provider-agnostic type-safe chat with streaming for OpenAI, Anthropic, Gemini, Ollama. Use for chat APIs, React/Solid frontends with useChat/ChatClient, isomorphic tools, tool approval flows, agent loops, multimodal inputs, or troubleshooting streaming and tool definitions.

Four-phase debugging framework that ensures root cause investigation before attempting fixes. Never jump to solutions. Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

shadcn-vue for Vue/Nuxt with Reka UI components and Tailwind. Use for accessible UI, Auto Form, data tables, charts, or encountering component imports, dark mode, Reka UI errors.

Implements secure session management with JWT tokens, Redis storage, refresh flows, and proper cookie configuration. Use when building authentication systems, managing user sessions, or implementing secure logout functionality.

SEO optimization with keyword analysis, readability assessment, technical validation, content quality. Use for search rankings, blog posts, content audits, or encountering keyword density, readability scores, meta tags, schema markup errors.

Configures HTTP security headers to protect against XSS, clickjacking, and MIME sniffing attacks. Use when hardening web applications, passing security audits, or implementing Content Security Policy.

Designs RESTful APIs with proper resource naming, HTTP methods, status codes, and response formats. Use when building new APIs, establishing API conventions, or designing developer-friendly interfaces.

Builds adaptive web interfaces using Flexbox, CSS Grid, and media queries with a mobile-first approach. Use when creating multi-device layouts, implementing flexible UI systems, or ensuring cross-browser compatibility.

Build recommendation systems with collaborative filtering, matrix factorization, hybrid approaches. Use for product recommendations, personalization, or encountering cold start, sparsity, quality evaluation issues.

React Native and Expo best practices for building performant mobile apps. Use when building React Native components, optimizing list performance, implementing animations, or working with native modules. Triggers on tasks involving React Native, Expo, mobile performance, or native platform APIs.

Type-safe React forms with React Hook Form and Zod validation. Use for form schemas, field arrays, multi-step forms, or encountering validation errors, resolver issues, nested field problems.

React composition patterns that scale. Use when refactoring components with boolean prop proliferation, building flexible component libraries, or designing reusable APIs. Triggers on tasks involving compound components, render props, context providers, or component architecture.

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.

Implements push notifications across iOS, Android, and web using Firebase Cloud Messaging and native services. Use when adding notification capabilities, handling background messages, or setting up notification channels.

Progressive Web Apps with service workers, web manifest, offline support, installation prompts. Use for installable web apps, offline functionality, push notifications, or encountering service worker registration, cache strategy, manifest configuration errors.