escpos-js

A pure JavaScript (ESModules) library for printing ESC/POS receipts, barcodes, and QR codes in Node.js.
✅ Works on macOS, Linux, and Windows using system print commands like lp and print.

🚀 Features

✅ ESC/POS command generation
✅ Formatted text (bold, underline, alignment, sizes)
✅ QR codes and barcodes
✅ Mock printer for unit testing
✅ No dependencies, no native bindings
✅ Fully cross-platform

📦 Installation

npm install escpos-js

📄 Usage Example

import {
  POSPrinter,
  POSReceiptBuilder,
  POSTextBuilder,
  POSPrintStyle,
  POSTextAlignment,
  POSBarcodeBuilder,
  POSBarcodeType,
  POSQRCodeBuilder,
  POSQRCodeSize,
  POSQRCodeErrorCorrection
} from "../lib/index.js";

const printer = new POSPrinter("Your_Printer_Name"); // See below to find the name

const receipt = new POSReceiptBuilder()
  .setTitle("ESC/POS DEMO")
  .addFeed()
  .addComponent(new POSTextBuilder("Left").setAlignment(POSTextAlignment.LEFT).build())
  .addComponent(new POSTextBuilder("Center").setAlignment(POSTextAlignment.CENTER).build())
  .addComponent(new POSTextBuilder("Right").setAlignment(POSTextAlignment.RIGHT).build())
  .addComponent(new POSTextBuilder("Bold").setStyle(POSPrintStyle.BOLD).build())
  .addItem("Item A", 3.5)
  .addItem("Item B", 5.0)
  .addComponent(
    new POSBarcodeBuilder("123456789012")
      .setType(POSBarcodeType.JAN13_EAN13)
      .build()
  )
  .addComponent(
    new POSQRCodeBuilder("https://example.com")
      .setSize(POSQRCodeSize.LARGE)
      .setErrorCorrection(POSQRCodeErrorCorrection.MEDIUM)
      .build()
  )
  .setFooter("Thank you!")
  .build();

printer.print(receipt);

🖨️ How to Find Your Printer Name

On macOS / Linux

lpstat -p

On Windows

Get-Printer | Select Name

🧪 Testing (Mock Printer)

import { POSPrinterMock, POSReceiptBuilder, POSTextBuilder } from "../lib/index.js";

const mock = new POSPrinterMock();
const receipt = new POSReceiptBuilder()
  .setTitle("Test")
  .addComponent(new POSTextBuilder("Line 1").build())
  .build();

mock.print(receipt);

console.log("Captured buffers:", mock.getPrintedData().length);

🛠 Notes

• Uses Node.js Buffer, fs, and child_process
• Output is written as a .bin file and printed using native system tools
• You must ensure your printer accepts ESC/POS and is installed correctly

📜 License

MIT