What it does
Universal Modder is a set of skills, tools and a shared knowledge base that let AI coding agents help modify PC games you own. The agent studies the game, reads its code and builds a mod.
It can also create art, 3D models and sound for mods using an outside creative service, test the mod in the running game, and record a showcase video.
It works with several AI coding agents, including Claude Code, Codex, Gemini and others.
Who it's for
Players and hobbyists who use an AI coding agent and want help making game mods.
Can I use it without coding?
With some setup. You install it into an AI coding agent and set up extra tools; it is aimed at fairly technical users. New to this? Start here.
Can I run it?
- Cost
- Free, but needs an AI accountThe software is free, but it uses an online AI service (like OpenAI or Anthropic), which usually charges for use.
- Runs on
- Mac, Windows, Linux
- Computer
- An ordinary computer is fine
- Privacy
- Sends what you give it to an online service
- API key
- Needed. An API key is a password-like code from an online AI service. What's that?
Try it
- Install the add-on into your chosen AI coding agent.
- Set up a key for the creative asset service if you want generated art.
- Point the agent at a game you own and describe the mod you want.
Using Claude Code, Cursor or another AI coding assistant? Paste the prompt and it will walk you through the setup.New to this?
Before you install
- Only download from the official GitHub page. Copies with similar names exist for many popular projects.
- License (MIT): Very permissive: free to use, change and share, including for business.
- Keep your API key private. Never paste it into websites or share it, and set a spending limit with the AI service.
- What you type or upload is sent to an online service. Avoid sharing private or sensitive information.
- More on staying safe