OpenTUI Core Development

Expert assistance for building terminal user interfaces with OpenTUI's imperative API.

Quick Start

# Install dependencies
bun install @opentui/core

# Zig is required for native modules
# Install from: https://ziglang.org/download/

Core Components

Basic Pattern

import { createCliRenderer } from "@opentui/core"
import { BoxRenderable, TextRenderable } from "@opentui/core"

async function main() {
  const renderer = await createCliRenderer()

  const box = new BoxRenderable()
  const text = new TextRenderable("Hello, OpenTUI!")
  box.add(text)

  renderer.getRoot().add(box)
  renderer.start()

  // Handle Ctrl+C to exit
  renderer.on("key", (key) => {
    if (key.name === "c" && key.ctrl) {
      renderer.destroy()
      process.exit(0)
    }
  })
}

main()

Layout with Yoga (CSS Flexbox)

import { Yoga } from "@opentui/core"

const group = new GroupRenderable()
group.setStyle({
  flexDirection: "column",
  justifyContent: "center",
  alignItems: "center",
  width: 80,
  height: 24,
})

See LAYOUT.md for all Yoga properties.

Input Handling

Keyboard Events

renderer.on("key", (key: KeyEvent) => {
  if (key.name === "escape") process.exit(0)
  if (key.name === "c" && key.ctrl) process.exit(0)
})

Component Input Events

const input = new InputRenderable()
input.on("submit", (value: string) => {
  console.log("Submitted:", value)
})
input.on("change", (value: string) => {
  console.log("Changed:", value)
})

See INPUT.md for complete event handling patterns.

Styling & Colors

import { Color, parseColor } from "@opentui/core"

// Create colors
const red = new Color(255, 0, 0)        // RGB integers
const blue = Color.fromInts(0, 0, 255) // Static method
const green = parseColor("#00FF00")     // Parse hex

// Apply styles
box.setStyle({
  backgroundColor: red,
  foregroundColor: blue,
  borderStyle: "double",
  paddingLeft: 2,
  paddingRight: 2,
})

See STYLING.md for color system and style properties.

Animations

import { Timeline } from "@opentui/core"

const box = new BoxRenderable()
const timeline = new Timeline({
  duration: 1000,
  easing: (t) => t * (2 - t), // easeOutQuad
})

timeline.to(box, {
  backgroundColor: new Color(255, 0, 0),
}, {
  onUpdate: () => renderer.render()
})

timeline.play()

See ANIMATION.md for animation patterns.

Debugging

// Enable console overlay
import { consoleOverlay } from "@opentui/core"
renderer.attach(consoleOverlay())

// Now console.log() appears in terminal overlay
console.log("Debug: initialized")

When to Use This Skill

Use /opentui for:

• Building TUIs with vanilla TypeScript/JavaScript
• Creating custom OpenTUI components
• Understanding core OpenTUI architecture
• Performance optimization
• Low-level debugging

For React-specific development, use /opentui-react For SolidJS-specific development, use /opentui-solid For project scaffolding and examples, use /opentui-projects

Common Tasks

• Create a form: Use BoxRenderable + InputRenderable components with Yoga layout
• Handle keyboard shortcuts: Listen to renderer "key" events
• Make scrollable lists: Use ScrollBoxRenderable with dynamic content
• Display code: Use CodeRenderable for syntax highlighting
• Add borders: Use BoxRenderable with borderStyle property

Resources

• Component API - Complete component reference
• Layout Guide - Yoga flexbox properties
• Event Handling - Keyboard, mouse, clipboard
• Styling - Colors, borders, spacing
• Animations - Timeline and easing
• Testing - Testing utilities

Key Knowledge Sources

• OpenTUI GitHub: https://github.com/sst/opentui
• Context7: /sst/opentui (168 code snippets, High reputation)
• Research: .search-data/research/opentui/