Infinite undo for AI coding agents.

SafeSandbox is a local-first developer tool that automatically creates snapshots and checkpoints while AI coding agents (Cursor, Claude Code, Codex, Aider, etc.) modify your repository.

What it does

• Automatic snapshots — detects bursts of file changes and creates restore points
• Rollback — restore your codebase to any previous snapshot in seconds
• Timeline — view a human-readable history of what changed
• Protection from destructive AI edits — never lose working code again

What it is NOT

• Not a cloud service — everything stays on your machine
• Not a remote IDE
• Not a Docker container
• Not an AI model
• Not a code editor

What it IS

• A local CLI tool
• A filesystem watcher (via chokidar)
• A git-based snapshot manager

Installation

npm install -g safesandbox
# or
pnpm add -g safesandbox

Or run without installing:

npx safesandbox init

Quick Start

# 1. Initialize SafeSandbox in your repo
cd my-project
safesandbox init

# 2. Start watching for changes
safesandbox watch

# 3. Let your AI agent work...
# SafeSandbox auto-creates snapshots when it detects bursts of edits

# 4. View timeline
safesandbox timeline

# 5. Roll back if something goes wrong
safesandbox rollback 12

Commands

safesandbox init

Sets up SafeSandbox in the current repository. Creates:

• .safesandbox/ directory with metadata storage
• A hidden snapshot branch for internal commits
• Config file with default thresholds

safesandbox watch

Starts filesystem monitoring. Detects:

• Multiple rapid file changes
• Deleted files
• package.json changes
• Lockfile changes (package-lock.json, pnpm-lock.yaml, yarn.lock, bun.lockb)

Snapshots are batched — not every single file write triggers one. You will see output like:

[SafeSandbox]
Snapshot #12 created
Reason: 24 files changed in 8 seconds

safesandbox timeline

Shows snapshot history:

#14 — 24 files changed
#13 — package.json modified
#12 — deleted docker-compose.yml

safesandbox rollback <id>

Restores the repository to the state at snapshot <id>. Asks for confirmation before destructive changes.

How it works

SafeSandbox uses git internally for snapshots:

• A hidden branch stores internal commits
• Metadata maps snapshot IDs to commit hashes
• Rollback uses git checkout + git restore for safe, precise restoration

No Docker. No overlayfs. No cloud. Just your local git repo + a smart watcher.

Configuration

After init, a config file lives at .safesandbox/config.json:

{
  "thresholdFiles": 5,
  "thresholdSeconds": 10,
  "ignoredPaths": ["node_modules", ".git", "dist", "build", ".safesandbox"]
}

• thresholdFiles — minimum files changed to trigger a snapshot
• thresholdSeconds — time window for batching changes

Example session

$ cd my-cursor-project

$ safesandbox init
[SafeSandbox] Initialized in /Users/me/my-cursor-project

$ safesandbox watch
[SafeSandbox] Watching for changes...

# ... you prompt Cursor to "add auth" ...

[SafeSandbox]
Snapshot #1 created
Reason: 12 files changed in 6 seconds

# ... you prompt again, it deletes something important ...

[SafeSandbox]
Snapshot #2 created
Reason: 3 files changed in 4 seconds

$ safesandbox timeline
#2 — 3 files changed
#1 — 12 files changed (auth feature)

$ safesandbox rollback 1
[SafeSandbox] This will restore 12 files to the state at snapshot #1.
Are you sure? (y/N) y
[SafeSandbox] Rolled back to snapshot #1.

Requirements

• Node.js >= 20
• Git repository (run git init first if needed)

License

MIT