About this project

Pattern MCP is a tool that assists coding agents in making UI component decisions before building. It evaluates components from libraries like shadcn/ui, 21st.dev, and ReUI against a requirements checklist, then recommends either using an existing component or building a custom one with references from Mobbin and Figma Community. It includes core tools (recommend_component, extract_requirements, record_component_decision) and advanced tools for design system registration, cost tracking, and ledger management. It supports enforcement via hooks and CI gates, and offers cost controls like prompt caching and ensemble checks for boundary cases.