Blessed.js Terminal UI Library Cheat Sheet

Blessed is a high-level terminal interface library for Node.js, bringing ncurses-like rich widget capability to modern JavaScript.

Screen Initialization

const blessed = require('blessed');

const screen = blessed.screen({
  smartCSR: true,       // optimize terminal redraw flickering
  autoPadding: true,
  title: 'My Dashboard'
});

screen.append(element);
screen.render();

// Handle global keyboard exits
screen.key(['escape', 'q', 'C-c'], (ch, key) => {
  return process.exit(0);
});

---

UI Elements (Box Widget)

const box = blessed.box({
  top: 'center',
  left: 'center',
  width: '50%',
  height: '50%',
  content: '{bold}Hello{/bold} Blessed!',
  tags: true, // enable inline formatting tags
  border: {
    type: 'line' // 'line' or 'bg'
  },
  style: {
    fg: 'white',
    bg: 'magenta',
    border: {
      fg: '#f0f0f0'
    },
    hover: {
      bg: 'green'
    }
  }
});

screen.append(box);

---

Formatting Tags

When tags: true is configured, elements parse inline formatting:

• {bold}...{/bold}: Bold text
• {underline}...{/underline}: Underlined text
• {center}...{/center}: Centered content
• {right}...{/right}: Right-aligned text
• {|}: Left/right horizontal alignment separator
• {#c0ff33-fg}...{/}: Custom hex foreground color

Escape tags in raw strings using blessed.escape(str).