Node.js

@thermal-label/labelmanager-node is the production package for server or desktop Node.js applications that need direct USB access to DYMO LabelManager printers.

Install

pnpm add @thermal-label/labelmanager-node

Quick example

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

const printer = await openPrinter();
await printer.printText('Warehouse A-12');
printer.close();

---

Printing text

Text is rendered using the built-in bitmap font pipeline from @mbtech-nl/bitmap.

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

const printer = await openPrinter();
await printer.printText('Fragile', {
  tapeWidth: 12, // mm — 6, 9, 12, or 19
  density: 'high',
  copies: 2,
  invert: false, // white-on-black
});
printer.close();

Text options

Option	Type	Default	Description
tapeWidth	6 | 9 | 12 | 19	12	Tape width in mm
density	"normal" | "high"	"normal"	Print density
copies	number	1	Number of copies to print
invert	boolean	false	White-on-black rendering

---

Printing images

printImage accepts file paths, image buffers, or pre-decoded raw image data. File path and buffer decoding requires optional @napi-rs/canvas.

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

const printer = await openPrinter();
await printer.printImage('./logo.png', {
  tapeWidth: 12,
  dither: true,
  threshold: 140,
  density: 'normal',
});
printer.close();

If @napi-rs/canvas is not installed, pass pre-decoded raw image data directly:

await printer.printImage({
  width: 200,
  height: 64,
  data: rawRgbaBuffer, // Uint8ClampedArray, RGBA
});

Image options

Option	Type	Default	Description
tapeWidth	6 | 9 | 12 | 19	12	Tape width in mm
density	"normal" | "high"	"normal"	Print density
copies	number	1	Number of copies
dither	boolean	false	Floyd-Steinberg dithering
threshold	number	128	Binarization threshold (0–255)

---

Multi-printer setups

Use serialNumber in openPrinter when multiple DYMO devices are connected.

Discover serial numbers

import { listPrinters } from '@thermal-label/labelmanager-node';

const printers = await listPrinters();
console.log(printers);
// [{ serialNumber: 'ABC12345', name: 'LabelManager PnP', ... }, ...]

Target a specific printer

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

const printer = await openPrinter({ serialNumber: 'ABC12345' });
await printer.printText('Station 3');
printer.close();

Targeting by serial number avoids race conditions in production systems with shared USB hubs.

---

Status checks

const status = await printer.getStatus();
console.log(status.ready); // false if printer is busy
console.log(status.tapeInserted); // false if no tape loaded
console.log(status.labelLow); // true when tape is almost out

---

API summary

Function / Method	Description
listPrinters()	List all connected compatible devices
openPrinter(opts?)	Connect and return a DymoPrinter
printer.printText(text, opts?)	Print a text label
printer.printImage(src, opts?)	Print an image label
printer.getStatus()	Read status flags
printer.close()	Close the USB device
generateUdevRules()	Return udev rule strings for Linux