universal-modder

Overview

universal-modder is a toolkit for pointing AI coding agents at PC games you own. It combines Agent Skills, a three-agent team, a Python um CLI, a shared field-note knowledge base, and the fal MCP so agents can perform recon, reverse engineering, asset generation, in-game testing, recording, packaging, and publishing. It supports Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, OpenCode, and skills-only setups.

Key Features

• Agent Skills bundle engine playbooks and workflows for recon, reverse engineering, asset generation, game automation, showcase video, publishing, porting, and sharing field notes.
• The um CLI scans Steam, Epic, and Xbox installs; fingerprints engine and version, .NET versus native, anti-cheat, loaders, save folders, and ranked modding routes.
• fal MCP and um fal generate sprites, images, textures, PBR maps, 3D models, rigs, sound effects, music, voice, and video, with local ComfyUI and separate Sprixen and Voidless integrations.
• A knowledge base stores field notes by agents for agents, covering exact working versions, chosen routes, engine behavior, verification, and gotchas, with commands to search, create, check, and open PRs.
• A three-agent team supports long mods: an orchestrator, a game worker that touches the running game, and an offline worker that studies data and writes generators and patches.
• Safety rules back up saves before changes, avoid anti-cheat and online cheating, never ship game files or decompiled code, and ask before input control, loader installation, or publishing.

Use Cases

• Add new weapons, enemies, bosses, civilizations, units, sprites, or textures to games such as Terraria and Age of Empires II DE.
• Port content between games, such as Halo weapons and vehicles into Minecraft or real Minecraft inside GTA V story mode.
• Investigate an unknown game install to identify its engine, prior modding work, and a viable modding route.
• Generate and pipeline images, 3D models, audio, and showcase videos into engine-ready assets.

Getting Started

• Install the plugin or extension for Claude Code, Codex, Gemini CLI, VS Code/Copilot, Cursor, or OpenCode; alternatively use the skills-only installer or clone the repository and start an agent inside it.
• For assets, create a fal API key and store it with um fal key set, or set FAL_KEY in the environment before starting the agent.
• If the agent install does not put um on PATH, install it once with uv tool install or pipx from the repository.
• Start with the mod-any-game skill; the agent searches the knowledge base, performs recon, backs up saves, reads code, builds a working slice, generates assets, verifies in-game, records, packages, and writes a field note.

Deployment & Requirements

• Git, Python 3.10+, and ffmpeg; uv is recommended. Blender is needed for 3D-to-sprite renders.
• Windows games are driven natively or from WSL.
• A fal API key powers the fal MCP server and um fal; without a key, fal OAuth browser sign-in can be used, and um comfy can make images on a local ComfyUI server.
• Sprixen and Voidless are separate paid services with their own API keys for certain 2D sprite workflows.

Before You Adopt

• License: MIT. Review its terms before using, modifying, or distributing the project.
• The tool requires Git, Python 3.10+, and ffmpeg.
• Blender is required for 3D-to-sprite renders.
• Voidless 2D sprite workflows use a separate paid service with its own API key.