DEDUPEDAuthorization notice. universal-modder is dual-use. Only use it on software, sites and systems you own or have explicit permission to test.
Who it is forTerraria player who wants a homing missile launcher and a custom boss but has never written a mod
The problemWriting a mod means learning the game's engine, code layout and asset formats before anything shows up on screen.
The outcomeA working mod with generated sprites, tested in the real game, plus a recorded showcase clip.
What you need first
- A coding agent such as Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot or OpenCode
- A PC game you own, run single-player or offline
- Git, Python 3.10+ and ffmpeg (uv recommended)
- A fal API key for generated art, 3D and audio (or a local ComfyUI server for images)
- Blender for 3D to sprite renders
- Windows games run natively or from WSL
Steps
- Install the plugin for your agent, for example
/plugin marketplace add rehan-remade/universal-modderthen/plugin install universal-modder@universal-modderin Claude Code. - Store your fal key with
um fal key setand start your agent with FAL_KEY set. - Tell the agent what to add, for example a homing missile launcher and a tactical nuke for Terraria, with sprites made by fal.
- Let it run the mod-any-game loop: recon, read the code, build one slice, generate assets, verify in game.
- Review the result and the showcase video it cuts.
Prompt for your agent
Use universal-modder to mod <game name> installed at <path to game folder>: add <new item or boss>. Generate the art with fal, test it in the running game, and tell me which route and engine you used.
Caveat. Targets games you own, single-player or offline only. The README says it refuses to bypass anti-cheat or write multiplayer cheats.
About universal-modder
Skills that let a coding agent mod almost any PC game you own. Part of this week's top 10 repos: ranked #7 on Repo Radar. View rehan-remade/universal-modder on GitHub.
More with universal-modder
- Turn a finished mod into a reusable field note Record the engine, route, versions and gotchas of your mod and open a pull request so the next agent starts ahead.
- Cut a showcase video of your finished mod Record the game window with only game audio, pick the best moments and edit a styled clip.
- Find a game's engine and see if it was modded before Point the agent at a game folder to get the engine, version, modding route and any existing field notes.
- Put one game's content inside another game Port characters, vehicles or mechanics from one game into a second, like Minecraft mobs in GTA V.
- Make sprites, 3D models and sound for a mod with fal Generate engine-ready sprites, 3D models, sound effects and music for a mod instead of drawing them by hand.
- Port an existing mod to a newer game version or loader Move a mod from an old Minecraft version or loader to a new one without behavior drifting.
- Reverse engineer an unknown game file format Have the agent decode a proprietary asset or save format and prove it with a round trip.
Disclaimer
Deduped lists open-source repositories that belong to other people. We do not own, maintain, audit, or vouch for any of them, and a repo appearing here is not an endorsement or a safety check. The use cases, steps, and prompts are written by AI and may be incomplete, outdated, or just wrong. Where a use case is marked "Seen in the wild", we link to public posts where someone described something similar, but we have not verified those posts and the use case itself is still our AI's own write-up. Use all of this at your own risk. Only run code, commands, or agents on systems and accounts you are authorized to use, and read the code and every command before you run it, especially anything that touches credentials, files, or the network. Nothing here is professional, security, legal, or financial advice. All trademarks and project names belong to their respective owners, and their use here does not imply affiliation. Content is provided as is, without warranties of any kind. Found a mistake, a safety problem, or something you want removed? Email [email protected] and we will look at it promptly. Full disclaimer page