Mermaid Diagrams

This gives Claude the full Mermaid syntax reference for creating text-based diagrams directly in your conversation. It covers the main types you'd actually use: class diagrams for domain modeling, sequence diagrams for API flows, flowcharts for processes, ERDs for database schemas, and C4 diagrams for architecture. The skill includes detailed syntax for relationships, cardinality, styling, and configuration options. What I like is that it's comprehensive enough to handle complex diagrams without needing to leave your workflow. The reference files break down each diagram type with concrete examples, so you can go from "I need to model this API interaction" to a proper sequence diagram without hunting through documentation.