cranebeaker / coop-anything

Co-op Anything 
 Any single-player game. Your friends. Your agent does the work. 
 Quick start ·
 How it works ·
 What you can co-op ·
 Games so far ·
 Contribute ·
 FAQ ·
 Docs 
Want to play a single-player game with your friends? Point your AI coding agent at this
repo. It researches what exists, reverse engineers the game and its engine if it has to,
builds or fixes the co-op, **tests it with bots inside the game**, and packages it so your
friends install it in one click and join over Steam without port forwarding.
The sky is the limit. Every game that runs on your PC is a candidate.
Games being made co-op right now: **Deus Ex** (released) ·
**Fallout: New Vegas** · **Zelda: Ocarina of Time** (fully synced) ·
**Dungeon Keeper** · **S.T.A.L.K.E.R. Shadow of Chernobyl**
From the community: **Mega Man X** and
**Mega Man X4** (native PC with co-op netplay) ·
**Pilotwings 64** (split-screen) ·
**Crab Champions** · **Stacklands** ·
**Half Sword** · **Enter the Gungeon** ·
**Clive Barker's Jericho** · **Poppy Playtime** ·
**Divinity II** (split-screen) · **Command & Conquer 3** (campaign co-op) ·
**Far Cry 2** · **Gothic 3** · **Fear & Hunger** · yours next?
## Quick start
Tell your agent (Claude Code, Codex, Gemini CLI, Cursor, OpenCode, ...):
 [code] 
The agent follows AGENTS.md and the skills in `.agents/skills`
(also in `.claude/skills` for Claude Code).
### Add the MCP server
The **Co-op Anything MCP** lets any agent search the co-op directory, detect a game's engine
from its install folder, read the playbook and skills, and validate contributions.
Claude Code picks it up from this repo's `.mcp.json`; for other agents:
 [code] 
Codex, Gemini CLI and Cursor setup: playbook/mcp.md. For the binary work,
pair it with a reverse-engineering MCP such as REA
(`npx rea-agents setup`): Co-op Anything knows what to do, REA looks inside the game.
## How it works
Your agent takes one of two paths.
| | Path 1: finish what exists | Path 2: build it from zero |
|---|---|---|
| When | A co-op mod exists but is buggy, stalled or abandoned. Most loved games are here. | Nothing usable exists. |
| How | Find the last build, mine its bug reports (issues, forums, Discord), audit the code, fix it as a separate package, test, ship. | Reverse engineer the game and engine, hook in, show the second player, sync enemies, world and story, handle level changes and saves, test, ship. |
| Skills | `coop-research`, `coop-revive`, `coop-qa` | `coop-reverse-engineer`, `coop-build-from-zero`, `coop-networking`, `coop-sync-testing`, `coop-qa` |
| Guide | Reviving abandoned mods | How co-op mods work |
Both paths end the same way: automated tests with real game clients
(QA), easy install, Steam relay networking
(networking), and a pull request back here.
### Sync test tools
Ready-made, game-agnostic tools for building and testing co-op sync, in `tools/`.
Each has tests, mutation twins and one command that prints `ALL OK`
(`python -I tools/test_all.py` runs them all).
| Tool | What it