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. Includes React 19 AP

The TypeScript framework for MCP servers: typed tools with Zod, dependency injection, auth, testing, agents and jobs, and builds for Node, Vercel, AWS Lambda and Cloudflare Workers.