Expo previews Exact, an app framework built for coding agents

• on the web, one ES module over a runtime of about 20 KB that drives the browser's real DOM and CSS
• on macOS and iOS, a Rust runner draws with the platform's own AppKit and UIKit controls
• on Linux, Exact paints the interface itself (GPU or CPU)

There is no webview and no JavaScript bridge in the UI. Layout follows CSS rules, which Cheever says makes it easier for agents to write because they already know CSS.

Why "agent native". The README says an agent can make an app, run it, look at it, operate it and prove it works without a person in the loop. It gives agents ten operations that work the same on every platform (tree, screenshot, tap, type, state, layout, logs, clock, prefer, perf). Agents control the app's clock instead of waiting on animations, and tests are scripts of those same operations that run unchanged on each platform. Compiler errors come back as machine-readable JSON.

Who it's for. Developers who already build apps with Claude Code, Codex or Cursor and want one codebase that ships as a native app on Apple platforms and a fast web app, with a loop the agent can check by itself.

The caveats.

• Very early. The README says Exact is pre-1.0 and "changes daily", with no API stability, no backwards compatibility and no migration guide, by design.
• Platform maturity varies. Cheever says iOS is the most mature; web and macOS are "pretty good"; Android, Windows and Linux work but are less mature. Per the README, Android delivery and store packaging don't exist yet, and there is no JSX/React layer.
• Heavy setup. You work from a source checkout (no packaged CLI yet). The README's quick start was run on an Apple Silicon Mac with Xcode, Rust, Bun and Chrome. In its own example, a fresh agent took about 57 minutes to build a todo app and pass tests on web, macOS and the iOS Simulator; about 25 of those minutes were first-time native builds.
• Not production-ready yet, by its author's estimate. Asked when it would be ready for production, Cheever replied it may be "2-3 months" before he could say he has confidence in it. TypeScript code also can't import code from npm packages yet.
• Speed claims in the launch thread (scrolling and startup comparisons against SwiftUI, UIKit and Shopify's app) are Cheever's own demos. MODEL has not checked them.

Disclosure: Not tested by MODEL. Not sponsored. No affiliate links.

MODEL Editors