Universal Modder
Skills, tools and a fal MCP that let Claude Code mod PC games you own: recon, reverse engineering, generated assets, in-game testing.
- GitHub stars
- 8,569 (GitHub stars as of 2026-10-21)
- License
- MIT
- Last commit
- 2026/10/21
- By
- rehan-remade
Listed from the author's README. GameSkill has not run this end to end yet. Agent support and install steps are as documented by the author.
Install
/plugin marketplace add rehan-remade/universal-modder
/plugin install universal-modder@universal-moddercodex plugin marketplace add rehan-remade/universal-modder
codex plugin add universal-modder@universal-moddergemini extensions install https://github.com/rehan-remade/universal-moddernpx skills add https://github.com/rehan-remade/universal-modderCommands are copied from the project's README. Check the repository before running anything on your machine.
Install for a specific agent
| Agents | -a | Folder |
|---|---|---|
| Claude Code | claude-code | .claude/skills/ |
| Codex | codex | .agents/skills/ |
| Cursor | cursor | .agents/skills/ |
| Gemini CLI | gemini-cli | .agents/skills/ |
| GitHub Copilot | github-copilot | .agents/skills/ |
| OpenCode | opencode | .agents/skills/ |
| Windsurf | windsurf | .windsurf/skills/ |
Add -a <flag> to the command. These are project folders; add -g to install for your user account instead.
What you get
- Recon and reverse-engineering skills for existing games
- The fal MCP server for generated art, 3D models and audio
- The `um` command-line tool
- In-game testing and showcase-video workflows
Good fit
- Single-player modding of games you own
- Learning how an existing game is put together
Not for
- Online or multiplayer games: modding them can break the game's terms of service or trigger anti-cheat bans
Overview
Universal Modder is the fastest-growing repository in this directory: it was created on 30 September 2026 and passed 8,000 stars within three weeks. It packages a modding workflow as Agent Skills, plus the fal MCP server and a small um CLI. You point the agent at a game, it finds out how the game is built, and it then writes and tests mods.
Each agent gets the same skills. Inside a clone they are mirrored into .agents/skills and .claude/skills, and the MCP config is already provided for Claude Code, Codex, Cursor, VS Code and OpenCode.
Before you start
Modding rules differ from game to game. Stick to single-player games you own, and read the game's EULA before you share anything you make.
Requirements
- A PC game you own
- A fal account for generated art, 3D and audio
FAQ
Similar skills
Scenario Skills
Production-ready images, video, audio and 3D from any agent through the Scenario MCP, plus expert teams for Blender, Unreal and Unity.
Create Game Assets
Plan, generate, source, normalize, and validate cohesive visual game assets.
Shader Programming
Write game shaders from cross-engine fundamentals — the vertex→fragment pipeline, coordinate spaces, UV math, and common 2D/3D effects (tint, UV scroll, dissolve, outline, fresnel rim, vignette) in GLSL with HLSL equivalents.
Playtest Report (Claude Code Game Studios)
Structured playtest report template, or turn existing playtest notes into structured feedback.