Excalidraw Skill

Programmatic control over Excalidraw canvases with proper iterative refinement built in. Works via MCP tools or a REST fallback, letting agents create diagrams, check their own work with screenshots, and fix spacing or overlap issues before moving on. The mandatory quality gate is the real value here: it forces you to verify text isn't truncated, arrows don't cross randomly, and elements have actual breathing room. Ships with coordinate planning guides and arrow routing patterns. You'll need the canvas server running locally, but once it's up you can script architecture diagrams, export to PNG or SVG, and manage snapshots. Best for agents that need to draw and iterate, not just dump JSON and hope.