ink

React for CLIs. Build and test your CLI output using components.

Ink provides the same component-based UI building experience that React offers in the browser, but for command-line apps. It uses Yoga to build Flexbox layouts in the terminal, so most CSS-like props are available in Ink as well. If you are already familiar with React, you already know Ink.

Since Ink is a React renderer, it means that all features of React are supported. Head over to React website for documentation on how to use it. Only Ink's methods will be documented in this readme.

Note: This is documentation for Ink 4 and 5. If you're looking for docs on Ink 3, check out this release.

^{My open source work is supported by the community ❤️}

Install

npm install ink react

Usage

import React, {useState, useEffect} from 'react';
import {render, Text} from 'ink';

const Counter = () => {
	const [counter, setCounter] = useState(0);

	useEffect(() => {
		const timer = setInterval(() => {
			setCounter(previousCounter => previousCounter + 1);
		}, 100);

		return () => {
			clearInterval(timer);
		};
	}, []);

	return <Text color="green">{counter} tests passed</Text>;
};

render(<Counter />);

You can also check it out live on repl.it sandbox. Feel free to play around with the code and fork this repl at https://repl.it/@vadimdemedes/ink-counter-demo.

Who's Using Ink?

GitHub Copilot for CLI - Just say what you want the shell to do.
Cloudflare's Wrangler - The CLI for Cloudflare Workers.
Linear - Linear built an internal CLI for managing deployments, configs and other housekeeping tasks.
Gatsby - Gatsby is a modern web framework for blazing fast websites.
tap - A Test-Anything-Protocol library for JavaScript.
Terraform CDK - CDK (Cloud Development Kit) for HashiCorp Terraform.
Specify CLI - Automate the distribution of your design tokens.
Twilio's SIGNAL - CLI for Twilio's SIGNAL conference. Blog post.
Typewriter - Generates strongly-typed Segment analytics clients from arbitrary JSON Schema.
Prisma - The unified data layer for modern applications.
Blitz - The Fullstack React Framework.
New York Times - NYT uses Ink kyt - a toolkit that encapsulates and manages the configuration for web apps.
tink - Next-generation runtime and package manager.
Inkle - Wordle game.
loki - Visual regression testing for Storybook.
Bit - Build, distribute and collaborate on components.
Remirror - Your friendly, world-class editor toolkit.
Prime - Open source GraphQL CMS.
Splash - Observe the splash zone of a change across the Shopify's Polaris component library.
emoj - Find relevant emojis.
emma - Find and install npm packages.
npm-check-extras - Check for outdated and unused dependencies, and run update/delete action over selected ones.
swiff - Multi-environment command line tools for time-saving web developers.
share - Quickly share files.
Kubelive - CLI for Kubernetes to provide live data about the cluster and its resources.
changelog-view - View changelogs.
cfpush - An interactive Cloud Foundry tutorial.
startd - Turn your React component into a web app.
wiki-cli - Search Wikipedia and read summaries.
garson - Build interactive config-based command-line interfaces.
git-contrib-calendar - Display a contributions calendar for any git repository.
gitgud - An interactive command-line GUI for Git.
Autarky - Find and delete old node_modules directories in order to free up disk space.
fast-cli - Test your download and upload speed.
tasuku - Minimal task runner.
mnswpr - Minesweeper game.
lrn - Learning by repetition.
turdle - Wordle game.
Shopify CLI - Build apps, themes, and storefronts for Shopify.
ToDesktop CLI - An all-in-one platform for building Electron apps.
Walle - Full-featured crypto wallet for EVM networks.
Sudoku - Sudoku game.

Getting Started
Components
Hooks
API
Testing
Using React Devtools
Useful Components
Useful Hooks
Examples

Getting Started

Use create-ink-app to quickly scaffold a new Ink-based CLI.

npx create-ink-app my-ink-cli

Alternatively, create a TypeScript project:

npx create-ink-app --typescript my-ink-cli

Manual JavaScript setup

Ink requires the same Babel setup as you would do for regular React-based apps in the browser.

Set up Babel with a React preset to ensure all examples in this readme work as expected. After installing Babel, install @babel/preset-react and insert the following configuration in babel.config.json:

npm install --save-dev @babel/preset-react

{
	"presets": ["@babel/preset-react"]
}

Next, create a file source.js, where you'll type code that uses Ink:

import React from 'react';
import {render, Text} from 'ink';

const Demo = () => <Text>Hello World</Text>;

render(<Demo />);

Then, transpile this file with Babel:

npx babel source.js -o cli.js

Now you can run cli.js with Node.js:

node cli

If you don't like transpiling files during development, you can use import-jsx or @esbuild-kit/esm-loader to import a JSX file and transpile it on the fly.

Ink uses Yoga - a Flexbox layout engine to build great user interfaces for your CLIs using familiar CSS-like props you've used when building apps for the browser. It's important to remember that each element is a Flexbox container. Think of it as if each <div> in the browser had display: flex. See <Box> built-in component below for documentation on how to use Flexbox layouts in Ink. Note that all text must be wrapped in a <Text> component.

Components

`<Text>`

This component can display text, and change its style to make it bold, underline, italic or strikethrough.

import {render, Text} from 'ink';

const Example = () => (
	<>
		<Text color="green">I am green</Text>
		<Text color="black" backgroundColor="white">
			I am black on white
		</Text>
		<Text color="#ffffff">I am white</Text>
		<Text bold>I am bold</Text>
		<Text italic>I am italic</Text>
		<Text underline>I am underline</Text>
		<Text strikethrough>I am strikethrough</Text>
		<Text inverse>I am inversed</Text>
	</>
);

render(<Example />);

Note: <Text> allows only text nodes and nested <Text> components inside of it. For example, <Box> component can't be used inside <Text>.

color

Type: string

Change text color. Ink uses chalk under the hood, so all its functionality is supported.

<Text color="green">Green</Text>
<Text color="#005cc5">Blue</Text>
<Text color="rgb(232, 131, 136)">Red</Text>

backgroundColor

Type: string

Same as color above, but for background.

<Text backgroundColor="green" color="white">Green</Text>
<Text backgroundColor="#005cc5" color="white">Blue</Text>
<Text backgroundColor="rgb(232, 131, 136)" color="white">Red</Text>