Pick one small change
Start with an item, a number, or one simple mechanic. Compare your setup with a documented example.
YOUR GAME. YOUR NEXT IDEA.
Universal Modder.Start small. Make it yours.
Turn “what if this game had…” into a clear first step. Explore the Universal Modder AI workflow, check the examples, and take a starter prompt to your local coding agent.
Free browser tool · No account · No game uploads
A GOOD MOD STARTS WITH A BRIEF
Minecraft Java / 1.21.1
One new tool. One small adventure.
“I want a pickaxe with a small light effect.”
- Match your game + loader version
- Back up a separate test world
- Ask your agent for a minimal plan
ILLUSTRATIVE PROJECT BRIEF / NOT A GENERATED MOD
Independent guide. Built for curious PC players.Original GitHub project
Prepare your first mod project
Choose your setup and describe one small change. Get a checklist and a prompt for your local coding agent.
Runs in your browser. Inputs are not uploaded, saved, or sent to an AI service.
FROM IDEA TO YOUR OWN COMPUTER
A little preparation goes a long way.
Get your tools ready
Install a local coding agent and the original project. Your game and its loader determine what else you need.
Build, test, and learn
Review the plan, work in a backup, and test the change in your own game. Keep a way to undo it.
FOLLOW THE EVIDENCE
Real notes. Specific versions.
These are reports from the original project, not tests performed by this website. An example is a starting point, not a compatibility guarantee.
01 / UPSTREAM
Terraria
A small arsenal for Terraria
An upstream weapon-and-enemy project using the tModLoader API. A useful example of working within a game’s mod loader.
- Recorded game version
- 1.4.4.9
- Tool route
- tModLoader 2026.07 GitHub build (Steam)
Upstream reports working
Not tested by this site · Source reviewed 2026-10-05
Read the upstream case02 / UPSTREAM
Minecraft Java
A new dimension, a new tool tier
A Minecraft Java example tied to NeoForge, covering a custom dimension and a tool tier.
- Recorded game version
- 1.21.1
- Tool route
- NeoForge 21.1.252 · JDK 21 (Oracle 21.0.11)
Upstream reports working
Not tested by this site · Source reviewed 2026-10-05
Read the upstream case03 / UPSTREAM
GTA V Legacy
Minecraft inside a GTA V scene
An advanced passthrough experiment combining two running games in GTA V Legacy story mode. It is not a ready-to-play download.
- Recorded game version
- Legacy 3889
- Tool route
- Steam build 3889 · ScriptHookV 3889.0 · ReShade 6.8.0
Upstream reports working
Not tested by this site · Source reviewed 2026-10-05
Read the upstream caseWhat is Universal Modder?
Universal Modder is an open-source collection of skills, a CLI and game-modding knowledge for coding agents. The work happens with tools on your computer. This independent website helps you prepare; it does not host a mod-generation service.
Is Universal Modder free?
The upstream project is MIT-licensed, and this guide and planner are free. Games, coding-agent subscriptions, API usage and optional asset-generation services can have their own costs. Check the provider before using a paid route.
Do I have to use Claude Code?
No. The upstream README documents several agent entry points, including Codex. Our setup guide starts with Claude Code. Choosing another agent in the planner changes the handoff text; it does not mean that combination has been tested.
Will it work with my game or version?
A documented example only covers its recorded setup. Unknown games, different versions and other operating systems need verification. Even an exact version match is not a guarantee that your idea will work.
Where is the download? Can I use my phone?
Get the original project through its GitHub installation instructions. There is no Universal Modder EXE or APK download offered here. You can read and prepare a prompt on your phone; game modding needs the appropriate local PC tools.
Do I need to know how to code?
An agent can help with code, but you still need to install tools, review changes and test your game. Begin with a small, reversible change in a separate single-player save. Do not treat generated code as automatically safe or working.