universal-modder

Universal Modder turns Claude Code (or Codex, Gemini CLI, Cursor and others) into a game-modding agent. It bundles skills for engine fingerprinting, reverse-engineering playbooks, asset generation, in-game testing and packaging, plus a Python CLI that scans your Steam, Epic and Xbox installs and ranks the routes for modding each game. MIT licensed.

Install it as a Claude Code plugin; you also need Git, Python 3.10+ and ffmpeg, plus Blender for 3D-to-sprite renders. Asset generation runs through fal's hosted models with a fal API key, or a local ComfyUI server for images without one. It asks before driving your mouse and keyboard, installing loaders into game folders, or publishing.

The plugin is free; the art isn't. fal bills per generation, about $0.08 per image on the default editing model, with 3D, sound and voice priced separately, and the skill tells the agent to warn you before running more than about 20 generations. Solo hobbyists modding games they own are the audience. The author works at fal, which the README doesn't mention.

The catch: the safety rules (no injecting into online games with anti-cheat, no cheats against other players, hands off DRM) are instructions to the agent, not enforcement. Its scope covers multiplayer games and servers you host, and the shared knowledge base already includes WoW private-server notes. It launched in late September 2026 with no versioned releases yet.