Ink

Ink brings the React component model to the terminal, letting developers build interactive CLI applications using the same JSX syntax, hooks, and component patterns they already know from web development. It uses Facebook's Yoga engine to support Flexbox layouts in the terminal, making CSS-like properties available for positioning and sizing. Since Ink is a full React renderer, all React features — including hooks, context, Suspense, and concurrent mode — work out of the box. It is used in production by tools like Claude Code, GitHub Copilot CLI, Cloudflare Wrangler, Gatsby, Prisma, and Shopify CLI.

• React-based UI — Write CLI UIs using JSX components like <Text>, <Box>, <Static>, and <Transform> with familiar React patterns.
• Flexbox layouts — Use CSS-like Flexbox properties (flexDirection, alignItems, justifyContent, gap, padding, margin) powered by the Yoga layout engine.
• Rich hooks API — Built-in hooks including useInput, usePaste, useApp, useStdin, useStdout, useWindowSize, useFocus, useFocusManager, and useCursor.
• Screen reader support — ARIA props (aria-role, aria-label, aria-state, aria-hidden) enable accessible CLI output for screen reader users.
• Concurrent & Suspense support — Enable React Concurrent Rendering mode for async data fetching, useTransition, and useDeferredValue.
• Incremental rendering — Optional incremental rendering mode updates only changed lines, reducing flicker for frequently updating UIs.
• Alternate screen buffer — Render apps in the terminal's alternate screen (like vim/htop) with automatic restoration on exit.
• Kitty keyboard protocol — Optional support for enhanced keyboard input including modifier keys, key event types (press/repeat/release), and key disambiguation.
• Testing support — Use ink-testing-library and renderToString() to unit-test CLI components without a live terminal.
• React Devtools integration — Inspect and modify component trees live using React Devtools by running with DEV=true.
• CI-aware rendering — Automatically adapts output for CI environments, writing only the final frame instead of continuously updating the terminal.
• Scaffolding tool — Bootstrap new projects instantly with npx create-ink-app supporting both JavaScript and TypeScript.