rehan-remade/universal-modder

What it claims

The repository packages one workflow, a skill named mod-any-game, plus a Python CLI (um) and a git-hosted knowledge base. It runs the same ten-step loop for any game:

1. search the knowledge base
2. recon, then pick a route
3. set up a safe lab with saves backed up
4. read the actual code
5. build one working slice
6. generate assets
7. verify in the real game
8. record
9. package
10. write a field note

The README says the loop was built from real agent sessions on Terraria, Age of Empires II and GTA V × Minecraft. The engine playbooks also draw on a "September 2026 wave of AI-built mods". The project is MIT licensed. A "mod hub" for publishing and remixing mods is announced but not yet shipped.

How it works

Where each agent finds things. In a clone, each agent looks in its own place, and all of these are copies of skills/:

• .agents/skills serves Codex, Gemini CLI, Copilot, Cursor and OpenCode.
• .claude/skills serves Claude Code.
• Instructions live in AGENTS.md. CLAUDE.md and GEMINI.md point to it.
• MCP config is duplicated per tool: .mcp.json, .codex/config.toml, .cursor/mcp.json, .vscode/mcp.json and opencode.json.

Field notes. Each note in knowledge/ records:

• the exact versions that worked
• the chosen route and why
• what the engine really does
• how the mod was verified
• gotchas, written as symptom → cause → fix

Bundled Windows tools. Two no-build tools ship in um/ps1/, both PowerShell with embedded C#:

• WinDrive, for input
• ProcLoopback, for game-only audio capture

Worked examples. The examples go beyond the summary in a few places:

• The AoE2 civ includes a reverse-engineered .sld sprite writer. Its units were rendered from fal image-to-3D models at AoE2's camera angle.
• The GTA V passthrough pairs a Fabric mod with a ScriptHookV + ReShade add-on. The two exchange camera, ground and events over a local WebSocket. Minecraft's colour and depth are depth-composited into GTA's frame.
• Community notes cover a Portal 2 passthrough, Halo 3 assets ported into Minecraft, Bloons TD 6 run as a headless sim, and an Elden Ring conversion written as a native Rust DLL.

How to use it

Plugin installs and clones put um on PATH. Anywhere else:

uv tool install git+https://github.com/rehan-remade/universal-modder     # or: pipx install git+...
export FAL_KEY=...

Requirements:

• Git, Python 3.10+ and ffmpeg. uv is recommended.
• Blender, for 3D → sprite renders.
• Windows games are driven natively or from WSL.
• Asset generation goes through fal (GPT Image 2, Nano Banana 2, FLUX, Trellis 2, ElevenLabs are listed), so it costs fal API usage.
• um comfy uses a local ComfyUI server for images without a key.

Knowledge-base workflow:

um kb search "grand theft auto"                 # before you start: prior art (works outside the repo too)
um kb new --game "Hades II" --title "A new boon god" --from-scan hades --agent "Codex (gpt-6)"
um kb check knowledge/games/hades-ii/a-new-boon-god.md
um kb pr knowledge/games/hades-ii/a-new-boon-god.md --yes    # after your human says OK: branch, push, PR

Every um command has --help with examples. The index is knowledge/INDEX.md.

Limits

Refusals built into the skill. It will not:

• inject into online games with anti-cheat
• write cheats against other players
• bypass anti-cheat, DRM or ownership checks

Scope. It targets games you own: single-player, multiplayer, or servers you host.

Output rules. It never ships game files or decompiled code. Mods ship only as code, your own assets, patches or converters. CONTRIBUTING.md applies the same rules to PRs and also requires an honest status and verification.

Confirmations. It asks before:

• driving your mouse and keyboard
• installing loaders into game folders
• publishing anything, including PRs

Process safety. It backs up saves first and kills processes by PID only. The full rationale is in skills/mod-any-game/references/safety.md.

Evidence quality. The page gives no success rates or failure accounts. Its evidence is the three shipped examples and community notes. Field notes are contributed by agents, so their reliability depends on the stated verification in each note.