Co-op Anything
Point your coding agent at a single-player game and make it co-op: an MCP server, 13 agent skills and a playbook to research, reverse engineer, build, bot-test and ship co-op mods with Steam relay networking.
- GitHub stars
- 1,235 (GitHub stars as of 2026-10-25)
- License
- MIT
- Last commit
- 2026/10/22
- By
- cranebeaker
Listed from the author's README. GameSkill has not run this end to end yet. Agent support and install steps are as documented by the author.
Install
Read https://github.com/cranebeaker/coop-anything and follow AGENTS.md.
I want to play <game> in co-op with my friends.Paste this to your agent. Skills live in .agents/skills (and .claude/skills for Claude Code).
claude mcp add coop-anything -- python <clone>/tools/mcp/coop_mcp.pyClaude Code picks it up from the repo's .mcp.json automatically. Pair with a reverse-engineering MCP such as REA.
Commands are copied from the project's README. Check the repository before running anything on your machine.
What you get
- 13 skills: coop-research, -revive, -reverse-engineer, -build-from-zero, -networking, -sync-testing, -qa, -decomp-port, -console-emulator, -switch, -triage, -contribute, triage-contributions
- The Co-op Anything MCP: search the co-op directory, detect a game's engine, read the playbook, validate contributions
- Sync test tools: chaos (lag/loss relay), flight (desync recorder), fuzz, ownership (C++), bots, animcheck, hotreload, mutants
- Playbooks for Unity, Unreal, Bethesda, Source, decomps and console emulators
Good fit
- Finishing a buggy or abandoned co-op mod
- Building co-op from zero, tested with bots inside the game
- Shipping mods friends install in one click and join over Steam
Not for
- Online games with anti-cheat
- Quick results: closed binaries need full reverse engineering
Overview
Co-op Anything turns "I want to play this with friends" into an agent task. The agent first researches what already exists, then takes one of two paths: revive a stalled co-op mod by mining its bug reports, or reverse engineer the game and build co-op from zero. Either way it ends with automated tests in real game clients, a one-click installer and a pull request back to the directory.
The repo is more than prompts. It ships an MCP server for the co-op directory and engine detection, and a set of game-agnostic sync tools, each with tests, from a lossy UDP relay to a desync flight recorder. All of it comes from the author's Fallout: New Vegas co-op work.
Its 1,200+ stars came with 161 forks, outside contributors and community co-op mods for games like Stacklands and Gothic 3, so the traction looks real.
Related
- Universal Modder for general game mods.
- Underhood for reverse engineering games you own.
- Unreal Vibe Modding for live Lua in Unreal games.
Requirements
- A coding agent (Claude Code, Codex, Gemini CLI, Cursor, OpenCode…)
- Python for the MCP server and test tools
- Per game: mod loaders and RE tools (BepInEx, UE4SS, SKSE, Ghidra, REA…)
Topics
FAQ
Works well with
Skills the author points to as related or as the better fit for neighbouring tasks.
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