Migrating from Ink

Rezi includes @rezi-ui/ink-compat, a drop-in compatibility layer that lets you run existing Ink applications on Rezi's native rendering engine with minimal code changes.

Why migrate?

	Ink	Rezi (via ink-compat)	Rezi (native)
Render speed	~17ms/frame	~0.06ms/frame	~0.025ms/frame
Throughput	60 ops/s	17,000 ops/s	38,900 ops/s
Memory (1000 items)	360MB RSS	251MB RSS	188MB RSS
Architecture	React + Yoga + ANSI	React + Rezi VNodes	createApp → diff → drawlist
Bundle	ink + yoga-wasm	react + @rezi-ui/*	@rezi-ui/core + @rezi-ui/node

Quick start

1. Install:

   npm install @rezi-ui/ink-compat @rezi-ui/core @rezi-ui/node react
   

2. Change your imports:

   - import { render, Box, Text, useInput, useApp } from "ink";
   + import { render, Box, Text, useInput, useApp } from "@rezi-ui/ink-compat";
   

3. That's it. Your app now runs on Rezi.

Supported components

All standard Ink components are supported:

Component	Status	Notes
<Box>	Supported	All flex props, borders, padding, margin, gap
<Text>	Supported	All style props (bold, dim, italic, color, etc.)
<Spacer>	Supported
<Newline>	Supported	Emulated via column layout
<Transform>	Supported	Text transformation
<Static>	Supported	Static output items

Supported hooks

Hook	Status	Notes
useInput()	Supported	Full key mapping including arrows, modifiers, special keys
useApp()	Supported	exit() with optional error
useFocus()	Supported	isFocused, focus(), autoFocus, id
useFocusManager()	Supported	focusNext(), focusPrevious(), focus(), enableFocus(), disableFocus()
useStdin()	Supported
useStdout()	Supported
useStderr()	Supported

render() options

const instance = render(element, {
  stdout: process.stdout,
  stdin: process.stdin,
  stderr: process.stderr,
  exitOnCtrlC: true,       // default
  patchConsole: true,       // default — captures console.log into app view
  debug: false,             // default
});

instance.rerender(newElement);
instance.unmount();
instance.clear();
await instance.waitUntilExit();

Known differences

• Rendering engine: Ink uses Yoga for layout + ANSI escape codes. Rezi uses its own layout engine + the Zireael C engine for terminal output. Visual output may differ slightly in edge cases.
• <Newline>: Emulated via column layout splitting (Ink uses literal \n).
• Console patching: Best-effort capture. In test environments (--test flag), console patching is automatically disabled.
• Throttling: Ink throttles renders at 32ms. Rezi renders on every state change (up to the FPS cap, default 60).

Gradual migration to native API

Once your app is running on ink-compat, you can gradually migrate components to the native Rezi API for maximum performance:

// Before (ink-compat React):
import { Box, Text } from "@rezi-ui/ink-compat";
const MyComponent = () => <Box><Text bold>Hello</Text></Box>;

// After (native Rezi):
import { ui } from "@rezi-ui/core";
const myWidget = ui.box({}, [ui.text("Hello", { style: { bold: true } })]);