Cowback — AI skill for Claude Code

[中文文档](./README_CN.md)

🐄 Cowback

**The missing Ctrl+Z for AI Agents.**

Cowback uses OS-native Copy-on-Write to create **near-instant, zero-cost snapshots** of your project before every AI agent operation. Break things freely. Restore in milliseconds.


Your AI agent just mass-deleted your source files. Now what? With Cowback: `cowback undo`. That's it.

Why this exists

I wrote some auto-update code for an Electron app I maintain. Routine stuff — clean up stale install artifacts before installing the new bundle. In production, the cleanup path resolved correctly: `app.getAppPath()` returned the bundled resources directory, two levels up was the right folder to clean.

In dev mode, on my machine, that same path computation resolved to `~/Desktop`. Then `rm -rf` ran on it.

I watched it happen. Icons on my desktop disappearing one by one — months of files, in-progress work, screenshots, notes — gone in a single `await fs.rm(...)`. No backup. By my own code. On my own machine. Three commits after I'd reviewed and tested the change. I've been writing code for ten years. I'd called out exactly this class of bug in other people's PRs. I wrote it anyway.

**This is what AI coding agents now do, all day, in production.** They write file operations. They run bash commands. They `rm -rf` paths they computed from variables. They edit configs in place. They mostly get it right — and every once in a while, they don't.

You can review their diffs. You can sandbox them. You can pray. Or you can have a `Ctrl+Z`.

That's what cowback is. Read [the full story](./STORY.md) if you want the gory details.

Why

AI coding agents (Claude Code, Cursor, OpenClaw, Codex, etc.) can modify files, run destructive bash commands, and break your project. Existing undo tools create full file copies to back up your project — **slow and wasteful.**

Cowback uses the same technology behind APFS and Time Machine: **Copy-on-Write file cloning.** Instead of