@thermal-label/letratag-web

Web Bluetooth driver for DYMO LetraTag LT-200B — connect and print labels directly from a Chromium-class browser via GATT.

Install

pnpm add @thermal-label/letratag-web

Quick start

import { requestPrinter } from '@thermal-label/letratag-web';
import { renderText } from '@thermal-label/letratag-core';

// Must be called from a user gesture (click handler).
const printer = await requestPrinter();
try {
  const bitmap = renderText('Hello LetraTag', { headDots: 32 });
  await printer.print(bitmap);
} finally {
  await printer.close();
}

Browser support

Web Bluetooth is required. Tested:

| Platform | Chrome | Edge | Firefox | Safari | | -------- | :----: | :--: | :-----: | :----: | | Linux | ✓ | ✓ | ✗ | n/a | | Windows | ✓ | ✓ | ✗ | n/a | | macOS | ✓ | ✓ | ✗ | ✗ | | Android | ✓ | ✓ | ✗ | n/a |

Firefox does not implement Web Bluetooth. Safari does not support it on macOS. iOS Safari has no Web Bluetooth — pair through a third-party app like Bluefy if you need iOS coverage.

Passive cassette / battery scanning

LT-200B continuously broadcasts cassette, battery, and error state in its BLE advertising packets. The web package can read this without a paired connection:

import { scanAdvertising } from '@thermal-label/letratag-web';

const stop = await scanAdvertising(status => {
  console.log('cassette loaded:', status.cassetteLoaded);
  console.log('battery level:', status.batteryLevel, '/ 3');
});
// Later:
stop();

Documentation

Full guide + TypeDoc reference: thermal-label.github.io/letratag/web.

For the hardware harness (verification flow): thermal-label.github.io/harness/letratag (bench-only today; hosted bundle pending).

1 devices — 1 verified · 0 partial · 0 broken · 0 untested

| Model | Key | USB PID | Transports | Status | | --- | --- | --- | --- | --- | | LetraTag LT-200B | LT_200B | — | BT LE | ✅ verified |

Click any model to open its detail page on the docs site, where engines, supported media, and verification reports live. The same data backs the interactive cross-driver table.