ShadowBox runs autonomous AI coding agents (Claude Code, Cursor, Aider, OpenHands) inside an ephemeral copy-on-write scratchpad on macOS and Linux. It strips secret credentials before the agent process spawns, isolates file mutations on an APFS zero-copy layer, and lets you review or discard changes before anything touches your real repository.

Quick Start

Run immediately with zero prior installation:

npx shadowbox-cli claude

Or install globally:

npm install -g shadowbox-cli
shadowbox aider

Requires macOS (APFS) or Linux.

Interactive Session

shadowbox session — zero-trust copy-on-write runtime

2 file(s) modified in sandbox:
  ● [A] src/auth/jwt.ts (+38 lines)
  ● [M] package.json (+1 line)

SECRETS BLOCKED (3)
  ● AWS_SECRET_ACCESS_KEY — stripped from process env
  ● GITHUB_TOKEN          — stripped from process env
  ● .env                  — masked with [SHADOWBOX_REDACTED]

HOST REPOSITORY
  ● 100% untouched, 0 unapproved writes

CONTROLS
  [c] Commit approved changes to host
  [q] Discard sandbox and leave host untouched
  [Tab] Toggle diff viewer

Key Features

• Zero-Copy CoW. Uses APFS clonefile() on macOS. Clones a 50,000-file project in ~14ms with 0 bytes additional disk usage. Real files remain untouched until you commit.
• SecretShield. Strips sensitive env vars (AWS_*, SSH_*, GITHUB_TOKEN, DATABASE_URL) from the agent's process environment and cloaks .env files with harmless mocks.
• One-key rollback. Interactive dual-pane TUI or headless mode. Commit with [c], abort and wipe with [q].

Links & Documentation

• GitHub Repository
• Architecture & Design Spec
• Implementation Plan
• Release Binaries (macOS & Linux)