vadimdemedes/ink

Ink is a library that lets you build interactive command-line applications using React, the same JavaScript framework normally used for building web user interfaces. The core insight is that a terminal's output is just text laid out in a grid, which is not so different from a web page. Ink maps React's component model onto the terminal so you can write CLI tools using familiar patterns: components, props, state, hooks like useState and useEffect, and the same declarative rendering approach you would use in a browser app. Under the hood, Ink uses Yoga, Facebook's implementation of the Flexbox layout algorithm, to position elements in the terminal. This means you can use CSS-like properties such as padding, margins, and flex direction to arrange text and boxes in your CLI output. It supports all standard React features including context, refs, suspense, and concurrent rendering. When state changes, Ink re-renders only the parts of the terminal output that changed rather than clearing and rewriting everything. You would use Ink when building a CLI tool that needs dynamic, interactive output, for example, a spinner showing download progress, a multi-step configuration wizard, a live dashboard updating in real time, or an interactive prompt. It is a particularly good fit if you already know React and want to apply that knowledge to terminal interfaces. The README notes it is used by several well-known tools including Claude Code, Gemini CLI, GitHub Copilot CLI, Cloudflare's Wrangler, Shopify CLI, and Prisma. The library is written in TypeScript, runs on Node.js, and is installed via npm.