electron-pos-printer

A powerful thermal POS printer library for Electron applications. Supports 58mm and 80mm thermal printers with raw ESC/POS commands.

Features

• Cross-platform: Works on Windows, macOS, and Linux
• Raw ESC/POS printing: Direct thermal printer control
• Support for 58mm and 80mm thermal printers
• Fluent API for building receipts
• Barcode and QR code support
• Table formatting with automatic column widths
• Full TypeScript support
• Works with Electron 28+

Installation

npm install electron-pos-printer

Quick Start

1. Main Process (main.ts)

import { app, BrowserWindow, ipcMain } from 'electron';
import { buildESCPOSData, printRawData } from 'electron-pos-printer';

// IPC handler for getting printers
ipcMain.handle('get-printers', async (event) => {
  return await event.sender.getPrintersAsync();
});

// IPC handler for printing
ipcMain.handle('print', async (event, contents, printerName, paperWidth) => {
  const escposData = buildESCPOSData(contents, paperWidth);
  return await printRawData(escposData, printerName);
});

2. Preload Script (preload.ts)

import { contextBridge, ipcRenderer } from 'electron';

contextBridge.exposeInMainWorld('printer', {
  getPrinters: () => ipcRenderer.invoke('get-printers'),
  print: (contents, printerName, paperWidth) =>
    ipcRenderer.invoke('print', contents, printerName, paperWidth),
});

3. Renderer Process (renderer.ts)

// Get available printers
const printers = await window.printer.getPrinters();

// Build and print a receipt
const contents = [
  { type: 'text', value: 'MY STORE', style: { align: 'center', bold: true, size: 'double' } },
  { type: 'text', value: '123 Main Street', style: { align: 'center' } },
  { type: 'line' },
  { type: 'table', rows: [
    [{ text: 'Item', bold: true }, { text: 'Price', align: 'right', bold: true }],
    [{ text: 'Coffee' }, { text: '$4.50', align: 'right' }],
    [{ text: 'Sandwich' }, { text: '$8.99', align: 'right' }],
  ]},
  { type: 'line' },
  { type: 'table', rows: [
    [{ text: 'TOTAL:', bold: true }, { text: '$13.49', align: 'right', bold: true }],
  ]},
  { type: 'feed', lines: 1 },
  { type: 'qrcode', value: 'https://mystore.com/receipt/123' },
  { type: 'feed', lines: 3 },
  { type: 'cut' },
];

const result = await window.printer.print(contents, 'POS-80', 80);
console.log(result.success ? 'Printed!' : result.error);

Using ReceiptBuilder (Fluent API)

import { createReceipt, buildESCPOSData, printRawData } from 'electron-pos-printer';

const receipt = createReceipt(80) // 80mm paper
  .setCurrency({ symbol: '$', symbolPosition: 'before' })
  .title('MY STORE')
  .textCenter('123 Main Street')
  .textCenter('Tel: (555) 123-4567')
  .line()
  .tableRow([
    { text: 'Item', width: '60%', bold: true },
    { text: 'Price', width: '40%', align: 'right', bold: true },
  ])
  .dashedLine()
  .row('Coffee', '$4.50')
  .row('Sandwich', '$8.99')
  .doubleLine()
  .totalRow('TOTAL:', 13.49)
  .feed(2)
  .qrcode('https://receipt.example.com/123')
  .feed(3)
  .cut();

const escposData = buildESCPOSData(receipt.getContents(), 80);
await printRawData(escposData, 'POS-80');

API Reference

Content Types

| Type | Description | Properties | |------|-------------|------------| | text | Text content | value, style | | line | Line separator | character | | table | Table rows | rows | | feed | Paper feed | lines | | cut | Cut paper | partial | | barcode | Barcode | value, options | | qrcode | QR Code | value, options |

Text Styles

interface TextStyle {
  bold?: boolean;
  underline?: boolean;
  align?: 'left' | 'center' | 'right';
  size?: 'normal' | 'double-height' | 'double-width' | 'double';
  invert?: boolean;
}

ReceiptBuilder Methods

| Method | Description | |--------|-------------| | text(value, style?) | Add text | | textCenter(value) | Add centered text | | textBold(value) | Add bold text | | title(value) | Large centered bold text | | line(char?) | Line separator | | dashedLine() | Dashed line | | doubleLine() | Double line (===) | | feed(lines?) | Feed paper | | cut(partial?) | Cut paper | | tableRow(columns) | Add table row | | row(label, value) | Two-column row | | totalRow(label, amount) | Bold total row | | barcode(value, options?) | Add barcode | | qrcode(value, options?) | Add QR code |

Platform Support

| Platform | Method | Requirements | |----------|--------|--------------| | Linux | CUPS (lp command) | CUPS installed, printer configured | | macOS | CUPS (lp command) | Printer in System Preferences | | Windows | Print Spooler | Printer installed, PowerShell |

Paper Width

| Width | Characters per Line | |-------|---------------------| | 58mm | 32 | | 80mm | 48 |

Requirements

• Node.js >= 18.0.0
• Electron >= 28.0.0

License

MIT