Exact is a new cross-platform UI framework by the Expo team that allows developers to write an app once and run it natively on the web, macOS, iOS, and Linux. A key feature is that an AI agent can build, run, and test the application across all these platforms without human intervention. The framework uses a declarative Contract language for the UI and TypeScript or Rust for data logic.
The Contract compiler generates a compact plan executed by a ~20 KB runtime on the web and a Rust runner on native platforms, utilizing native UI components like App Kit, UIKit, and a GPU painter, avoiding webviews and JavaScript bridges. The framework is designed for AI-native development, featuring a standardized set of ten operations for agents to drive the app on any host. While demonstrating capabilities with a TODO list app and a Softwear store showcase, Exact is currently pre-1.0, meaning there is no API stability, backwards compatibility, or migration guide.
The source code is available on GitHub, and initial setup requires a Mac with Xcode, Rust, Bun, and Chrome.
Source: Hacker News · Summarized by HeadlinesBriefing