Node.js guide

@thermal-label/marklife-node exposes:

• MarklifePrinter — the PrinterAdapter, over any Transport from @thermal-label/transport/node.
• MarklifeDiscovery — opens an OS-paired Bluetooth SPP port by deviceKey.
• discovery — the default MarklifeDiscovery, exported for thermal-label-cli's driver auto-detection.

Bluetooth SPP

Every chassis but the X2 BLE entry speaks Classic Bluetooth SPP. Pair at the OS and the channel surfaces as a serial port; RFCOMM carries no identity, so deviceKey is required.

import { MarklifeDiscovery, MEDIA } from '@thermal-label/marklife-node';

const printer = await new MarklifeDiscovery().openBluetoothSpp({
  serialPath: '/dev/rfcomm0',
  deviceKey: 'S8',
});
await printer.print(image, MEDIA.GAP_50X30);
await printer.close();

Linux

bluetoothctl
> scan bredr
> pair AA:BB:CC:DD:EE:FF                 # PIN 1234 on the P12 / P15; the S2 asks for none
> trust AA:BB:CC:DD:EE:FF
> exit
sudo rfcomm bind 0 AA:BB:CC:DD:EE:FF 1    # channel 1 is the SPP channel

The Classic address is not the BLE one: these chassis advertise a random LE address, so take the MAC from a bredr scan, where the name appears without the _BLE suffix.

macOS — after pairing in System Settings → Bluetooth the port is /dev/tty.<Name>-SPPDev.

Windows — pair in Settings → Bluetooth & devices; the outgoing COM port appears under Device Manager → Ports.

USB

The P12 (09c7:0011) and P15 (5958:0015) are USB Printer-class devices and print the same byte stream. MarklifeDiscovery does not open USB; construct the printer over UsbTransport:

import { UsbTransport } from '@thermal-label/transport/node';
import { DEVICES } from '@thermal-label/marklife-core';
import { MarklifePrinter, MEDIA } from '@thermal-label/marklife-node';

const transport = await UsbTransport.open(0x09c7, 0x0011);
const printer = new MarklifePrinter(DEVICES.P12, transport, 'usb');
await printer.print(image, MEDIA.CONTINUOUS_15MM);

@thermal-label/transport declares usb as an optional peer; install it in the application that opens USB.

BLE

MarklifeDiscovery.openBluetoothGatt throws — no Node BLE backend is wired. Build a Transport over the BLE library of your choice and pass it to new MarklifePrinter(entry, transport, 'bluetooth-gatt'). On Profile A the chassis gates writes on credits published on ff03; see the protocol index. The web package's MarklifeBleTransport is the reference implementation.

MarklifePrinter

class MarklifePrinter implements PrinterAdapter {
  constructor(device: DeviceEntry, transport: Transport, transportType: TransportType, options?: MarklifePrinterOptions);
  readonly family: 'marklife';
  readonly device: DeviceEntry;
  readonly transportType: TransportType;
  get model(): string;
  get connected(): boolean;
  print(image: RawImageData, media?: MediaDescriptor, options?: MarklifePrintOptions): Promise<void>;
  createPreview(image: RawImageData, options?: PreviewOptions): Promise<PreviewResult>;
  getStatus(): Promise<MarklifeStatus>;
  close(): Promise<void>;
}

interface MarklifePrinterOptions {
  threshold?: number;          // dither threshold, 0..255; per-engine default
  interChunkDelayMs?: number;  // pause between packets; registry default
}

• print() encodes the job for the entry's engine and feeds it to the transport in registry-sized packets with a pause between them — the pacing every chassis needs, on USB and SPP as much as on BLE. It throws MediaNotSpecifiedError without a media descriptor.
• getStatus() reports link state only. There is no onStatus; consumers that want a push shape poll getStatus().
• print() and getStatus() are serialised against each other.

Discovery semantics

• listPrinters() returns [] — RFCOMM ports carry no model identity and USB is not enumerated here.
• openPrinter({ serialPath, deviceKey }) delegates to openBluetoothSpp.
• openPrinter({ host }) and openPrinter({ vid, pid }) throw.