Zag is an AI review agent platform for teams shipping iOS, iPadOS, and macOS apps. You describe review agents in TypeScript or Swift that actually build, test, and run your app on every PR, catching bugs and security issues before they reach a human reviewer. Under the hood, Zag runs on dedicated Apple Silicon in real macOS environments with Xcode, simulators, and your full toolchain. Zag offers at-cost macOS compute at $0.015/min - 5× cheaper than any other macOS runner on the market.