Getting started

Node.js

Install

npm install @thermal-label/labelwriter-node

Print text over USB

import { openPrinter } from '@thermal-label/labelwriter-node';

const printer = await openPrinter();
try {
  await printer.printText('Hello, world!');
} finally {
  await printer.close();
}

Print over TCP (wireless models)

import { openPrinterTcp } from '@thermal-label/labelwriter-node';

const printer = await openPrinterTcp('192.168.1.100');
try {
  await printer.printText('Shipped!', { density: 'high' });
} finally {
  await printer.close();
}

Linux udev rule

On Linux, USB access requires a udev rule. Create /etc/udev/rules.d/99-labelwriter.rules:

SUBSYSTEM=="usb", ATTR{idVendor}=="0922", GROUP="plugdev", MODE="0664"

Then reload rules and add your user to the plugdev group:

sudo udevadm control --reload-rules
sudo usermod -aG plugdev $USER

Log out and back in for the group change to take effect.

CLI

Install globally

npm install -g @thermal-label/labelwriter-cli

Quick examples

# List connected printers
labelwriter list

# Print a text label
labelwriter print text "Hello, world!"

# Print with options
labelwriter print text "Fragile" --density high --copies 3

# Check printer status
labelwriter status

# Print image
labelwriter print image ./label.png --threshold 128

See the CLI reference for all commands and flags.

Web (browser)

Install

npm install @thermal-label/labelwriter-web

Requires Chrome or Edge (WebUSB is not supported in Firefox or Safari). Must be served over HTTPS or localhost (secure context requirement).

Quick start

import { requestPrinter } from '@thermal-label/labelwriter-web';

// Triggers browser's USB device picker
const printer = await requestPrinter();
await printer.printText('Hello from the browser!');
await printer.disconnect();

NFC label lock

What is it?

The Dymo LabelWriter 550 series (550, 550 Turbo, 5XL, and related models) includes hardware-level NFC validation. Before printing, the printer reads an NFC chip embedded in the label roll. If the chip is absent or not recognised as a genuine Dymo label, the printer reports a paper-out error and refuses to print.

Which models are affected?

All protocol: '550' devices — see Hardware for the full list. The 450 series and older models do not have this restriction.

Can it be bypassed?

No. The NFC check is performed entirely within the printer's own firmware, independent of the host software. There is no command or sequence that disables it. Using genuine Dymo-certified label rolls is the only solution.

What does the error look like?

getStatus() will return { ready: false, paperOut: true, errors: ['Paper out'] }. The printer will also show a blinking orange LED.