Game reconnaissance
Scan installations, identify engines and versions, find loaders and saves, then rank possible modding routes.
OPEN SOURCE AI GAME MODDING
Universal Modder:
Mod Any PC Game with AI
Turn Claude Code, Codex, Cursor and other coding agents into game-modding assistants. Universal Modder helps an agent inspect a game, choose a route, build assets, test the result, and document what it learns.
CLAUDE CODE / INSTALL
$ /plugin marketplace add rehan-remade/universal-modder
$ /plugin install universal-modder@universal-modderWORKS WITHClaude CodeOpenAI CodexCursorGemini CLIGitHub CopilotOpenCode
AGENT SESSION um · scan
01$ um scan ~/Games/Terraria
02✓ Game found · Terraria 1.4.4
03✓ Engine · XNA / tModLoader
04✓ Route · tModLoader API
↳MODDING_PLAN.mdREADY
Build one working slice, verify in game, record the route.
✣SPRITE
♫ASSET
▶IN GAME
RECON BUILD VERIFY
Independent guide to the open-source Universal Modder project. Source repository
01 / THE TOOLKIT
What is Universal Modder?
Instead of starting from zero on every game, an AI coding agent can follow a repeatable process to investigate the engine, inspect the project, and select a practical modding route.
Reverse-engineering workflows
Use established tools and repeatable methods to inspect code, formats, and behavior.
AI asset pipeline
Create sprites, textures, 3D assets, audio, and supporting media with fal-powered workflows.
Real-game verification
Launch the game, exercise a mod in context, capture evidence, and record what worked.
02 / THE PROCESS
From an idea to a working game mod
One deliberate loop helps the agent move from investigation to a testable result. Start small, verify in the real game, then keep the useful findings.
01
Search knowledge
Start with field notes from earlier work.
02
Scan the game
Find the install and collect technical clues.
03
Detect engine
Identify engine, version, loaders, and constraints.
04
Choose a route
Write a plan that fits this game.
05
Build a slice
Get one small feature working first.
06
Generate assets
Make and adapt art, 3D, or audio.
07
Test in game
Check behavior in the actual running game.
08
Package and record
Prepare the mod and preserve useful findings.
COMPATIBLE AGENTS
Use the coding agent you already have
Universal Modder uses Agent Skills and compatible instruction and configuration formats to share a modding method across coding agents.
⌘Claude Code↗
◈OpenAI Codex↗
◉Cursor↗
✳Gemini CLI↗
◆GitHub Copilot↗
⌬OpenCode↗
03 / ENGINE COVERAGE
Built for more than one game engine
Playbooks span commercial engines, game-specific ecosystems, and indie frameworks. Actual support depends on the title and its modding constraints.
01Unity
02Unreal Engine
03.NET / XNA / FNA
04Godot
05Source 1 / Source 2
06Bethesda
07Minecraft
08Age of Empires / Genie
09RE Engine
10FromSoftware games
11GTA / RAGE
12Cyberpunk / REDengine
13Baldur’s Gate 3
14Native C++
15GameMaker
16RPG Maker
17Ren’Py
18Paradox
19Doom
20HTML5 games
21LÖVE
22Java games
NOTE Modding support depends on the individual game, engine, loader ecosystem, and technical restrictions.
04 / BUILT WITH THE TOOLKIT
Examples from the repository
These are documented project examples, not guarantees that the same result is available for every game or setup.
TERRARIA / TML✦01
Terraria
A tModLoader example with weapons, enemies, a boss, and generated sprites.
Explore exampleAOE II / DE⌖02
Age of Empires II
A custom civilization, units, a wonder, and a reverse-engineered sprite writer.
Explore exampleGTA V × MINECRAFT▧03
GTA V + Minecraft
A story-mode passthrough experiment connecting game visuals and events.
Explore example+
And your own ideas
Items, mechanics, characters, textures, sounds, maps, and gameplay experiments—subject to what each game allows.
05 / QUICK START
Install Universal Modder
Pick an agent to see the repository’s documented setup command.
CLAUDE CODE / SETUP
$ /plugin marketplace add rehan-remade/universal-modder
$ /plugin install universal-modder@universal-modder
Add the project marketplace, then install its plugin.
REQUIREMENTS
Python 3.10+ffmpegfal API key for generated assetsBlender for 3D-to-sprite workflowsWindows or WSL for Windows game automation06 / TRY A REAL PROMPT
Start with one sentence
Describe a concrete mod idea and let your coding agent turn it into an investigation plan. You stay in control of choices that affect files, saves, and the running game.
Read the project workflow EXAMPLE PROMPT
“Mod Terraria: add a homing missile launcher and a tactical nuke that craters the world. Make the sprites with fal.”
01Prompt
02Game Recon
03Modding Plan
04Code + Assets
05In-Game Test
06Working Mod
⌘ SHARED KNOWLEDGE BASE
knowledge/games/terraria/tmodloader-weapons.md
# Field note
Engine: XNA / tModLoader
Versions: 1.4.4 · verified locally
Route: ModItem + ModProjectile
Test: launch game, inspect behavior
Gotcha: sync projectile state$ um kb search "grand theft auto"
07 / REUSABLE FIELD NOTES
A knowledge base written for the next agent
Completed work can leave notes for the next coding agent, so it can start with proven discoveries instead of repeating the same reverse-engineering work.
- Exact game and tool versions
- Engine and modding route
- Technical discoveries and verification
- Problems, fixes, and gotchas
!
PROJECT SAFETY RULES
Designed for legitimate game modding
This guide focuses on single-player and offline modding for games you own. The project rules prohibit bypassing DRM, ownership checks, or anti-cheat, and prohibit cheats against other players. Do not redistribute game files or decompiled proprietary code.
08 / FAQ
Universal Modder questions
Quick answers about installation, supported agents, AI game modding, and the limits of automated workflows.
What is Universal Modder?
Universal Modder is an open-source toolkit that gives compatible AI coding agents game-recon, modding, asset, testing, and knowledge-base workflows for PC games. It is a toolkit for coding agents, not a one-click browser generator.
Is Universal Modder free?
The repository is MIT licensed. Some asset-generation workflows use fal and require a fal API key; check the provider for current pricing and terms.
Is Universal Modder open source?
Yes. The project repository identifies its license as MIT. Review the repository and license for the current source and terms.
Can Universal Modder mod any PC game?
No tool can guarantee support for every game. The usable route depends on the game, engine, version, loaders, technical restrictions, and what the agent can inspect.
Does Universal Modder work with Claude Code?
Yes. The repository documents a Claude Code marketplace installation and provides Agent Skills, tools, and a shared knowledge base.
Does Universal Modder work with OpenAI Codex?
Yes. The repository documents a Codex plugin marketplace installation.
Does Universal Modder work with Cursor?
The repository lists Cursor support through its marketplace or a repository clone, with project instructions and MCP configuration.
Which game engines does Universal Modder support?
Its playbooks cover Unity, Unreal, Godot, .NET/XNA/FNA, Source, Bethesda, Minecraft, Age of Empires/Genie, RE Engine, FromSoftware, GTA/RAGE, Cyberpunk/REDengine, Baldur’s Gate 3, native C++, and several indie and legacy engines. Individual games still vary.
Can AI create game mods automatically?
An agent can use the toolkit to investigate a game, choose a modding route, implement a small working slice, create assets, and test it. The process still depends on the game and may require user decisions or manual work.
How do I install Universal Modder?
Choose the instructions for your coding agent in the Install section. Claude Code and Codex use plugin marketplace commands; Gemini CLI uses an extension install command; skills-only users can use npx skills add.
Does Universal Modder require coding knowledge?
A coding agent can handle many implementation steps, but users still need to describe the goal, review changes, provide required tools or credentials, and make decisions when the game or workflow needs them.
Can Universal Modder generate game assets?
Its fal-powered workflows cover image, sprite, texture, 3D, audio, and video tasks. Generated assets may need conversion or adjustment to fit a specific game.
Is Universal Modder safe to use?
The project documents safeguards against anti-cheat evasion, DRM or ownership-check bypasses, and multiplayer cheats. Back up saves and review changes; do not redistribute game files or decompiled proprietary code.
Where is the Universal Modder GitHub repository?
The source repository is github.com/rehan-remade/universal-modder.
MAKE THE FIRST SLICE WORK
Turn your next game mod idea into a working prototype
Give your coding agent a game, an idea, and the Universal Modder toolkit.