Astah Pro MCP Brings AI Agents to UML Modeling

Summary

Astah Pro MCP is an experimental local Model Context Protocol server that runs as a plugin for Astah Professional, a UML modeling tool. It lets AI agents design systems as UML models, explain existing models, generate source code from them, convert source code back into models, and create diagrams from hand-drawn sketches. The project includes an experimental programmatic tool-calling mode on port 8888 that exposes 83 tools, while a direct mode on port 18888 exposes 398 tools. Claude Code, Codex CLI, Grok Build, Antigravity, Cursor, and Kiro are listed as tested clients, and Astah Professional 12.0 or later is required. Supported work includes class, sequence, activity, state machine, use case, mind map, requirement, composite structure, communication, and ER diagrams, although some types are query-only or have limitations. The server connects only to agents running on the same machine as Astah. The documentation says AI-agent use requires a valid Astah license for the user’s own use and prohibits unlicensed third-party operation. Installation consists of installing Astah, dropping the plugin JAR into it, restarting the application, and configuring the agent to use the local MCP endpoint. Users must confirm each new connection, and the project recommends backups because agents can edit model elements and diagrams. The authors warn that the project is experimental and may introduce breaking changes; confidential project data and logs may be shared with the agent, some model properties remain inaccessible through the tools, and AI-generated changes may contain mistakes. The plugin also does not optimize token usage, so the documentation recommends flat-rate AI plans. It is released under MIT-0 for the project’s own code, with separate attribution and licensing conditions for quoted UML, SysML, IDEF1X, and diagram-consistency material.