drawio-skill is a comprehensive AI agent skill for generating, editing, synchronizing, inspecting, testing, and publishing editable draw.io diagrams from natural language, codebases, infrastructure-as-code, and data schemas. It provides a unified CLI (`diagramctl.py`) orchestrating a pipeline of 39+ specialized scripts covering importers (Python, JS/TS, Go, Rust, Terraform, K8s, Docker, SQL DDL, OpenAPI, CI pipelines), auto-layout (Graphviz, ELK, deterministic sequence/C4/tube-map), shape search (10k+ official icons), AI/LLM brand logos (321 brands), style presets, diagram diff, time-lapse, heat maps, and export (PNG, SVG, PPTX, Mermaid, HTML viewer). The architecture is centered on a versioned Diagram IR (JSON Schema) that separates meaning, provenance, and geometry, enabling incremental sync preserving manual layout, multi-view projection, architecture contract testing (Diagram-as-Test), what-if failure simulation, and accessible Story Mode. It integrates with agent platforms via a SKILL.md and an optional MCP server (`diagramctl_mcp.py`) exposing nine tools over stdio, and supports CI integration through GitHub Actions for PR diff and architecture test gates. The project is actively maintained with semantic versioning, 174 unit tests, and a changelog tracking releases through v3.2.0.