Core API

@thermal-label/marklife-core is the shared protocol layer under both runtime packages: six job encoders behind one dispatch, the device and media registries, the send-pacing table, the offline preview, and the @thermal-label/contracts base types re-exported for convenience. It has no transport code and no Node builtins, so it runs in a browser unchanged.

pnpm add @thermal-label/marklife-core

Looking for byte-level details?

The protocol reference documents every opcode and job stream — L11, YXQ, CPCL, JBIG, TSPL, ESC/POS.

Exports

Export	Description
DEVICES / REGISTRY_MARKLIFE / findDevice / findDeviceByName / findDeviceByUsbIds	Device registry and lookups. findDeviceByName matches an advertised or paired name by longest registry prefix (P12_ZA15B_BLE → P12).
MEDIA / ALL_MEDIA / DEFAULT_MEDIA / findMediaByDimensions	Media registry and lookups. DEFAULT_MEDIA backs the offline preview only; print() never assumes it.
encodeJobForEngine(engine, page) / isEngineDrivable(engine)	Dispatch on engine.protocol; the guard is false for marklife-jbig while its payload encoder is missing.
encodeL11Job / encodeYxqJob / encodeCpclJob / encodeJbigJob / encodeMarklifeTsplJob / encodeMarklifeEscposJob	The per-protocol encoders, with their is*Engine guards and byte builders.
pacingFor(device) / DEFAULT_PACKET_BYTES / DEFAULT_PACKET_DELAY_MS	Packet size and inter-packet pause for a chassis, from its registry entry.
yxqZlibCompress / yxqZlibDecompress / tsplZlibCompress	The two deflate paths — 1 KiB window for YXQ and CPCL, default window for TSPL.
parseYxqStatus / YXQ_QUERY_OPCODES	Structural decoder for a status reply no chassis has yet been seen to send.
createPreviewOffline(image, options?)	PreviewResult without a connection.
ROTATE_DIRECTION / pickRotation	The family's rotation direction and the contracts helper that applies it.
renderImage / renderText / rotateBitmap / padBitmap / scaleBitmap	Bitmap helpers re-exported from @mbtech-nl/bitmap.
MarklifeDevice, MarklifeEngine, MarklifeMedia, MarklifePrintOptions, MarklifeStatus, MarklifeProtocol, …	Driver types.
PrinterAdapter, MediaDescriptor, Transport, MediaNotSpecifiedError, UnsupportedOperationError, …	Re-exported from @thermal-label/contracts.

Key types

type MarklifeProtocol =
  | 'marklife-l11' | 'marklife-yxq' | 'marklife-cpcl'
  | 'marklife-jbig' | 'marklife-tspl' | 'marklife-escpos';

interface MarklifeEngineCapabilities {
  protocolId?: number;          // per-id variant inside marklife-yxq / -jbig
  compression?: 'zlib' | 'jbig' | 'lzo-mode-3' | 'none';
  bitPolarity?: '1=dark' | '0=dark';
  physicalSizeClass?: 0.5 | 2.0 | 3.0 | 4.0;
  headWidthMm?: number;
  realSeries?: string;          // base chassis of a whitelabel
  bleProfile?: 'A' | 'B' | 'C' | 'D' | null;
  redBlackDuplex?: boolean;
  interChunkDelayMs?: number;   // pause between packets; family default 30
}

interface MarklifeMedia extends MediaDescriptor {
  targetModels: readonly ('narrow-tape' | 'mobile-2in' | 'desktop-3in' | 'industrial-4in')[];
}

interface MarklifePrintOptions extends PrintOptions {
  densityLevel?: number;                    // wins over `density`
  rotate?: 'auto' | 0 | 90 | 180 | 270;
}

interface MarklifePage {
  bitmap: LabelBitmap;
  media: MarklifeMedia;
  options?: MarklifePrintOptions;
}

Usage

Encode a job

import { DEVICES, MEDIA, encodeJobForEngine, renderImage } from '@thermal-label/marklife-core';

const engine = DEVICES.S2.engines[0]!;
const bitmap = renderImage(image, { dither: true, threshold: 128 });
const bytes = encodeJobForEngine(engine, { bitmap, media: MEDIA.GAP_50X30 });

bytes is the whole job. Feed it to a transport in packets:

import { pacingFor } from '@thermal-label/marklife-core';

const { packetBytes, delayMs } = pacingFor(DEVICES.S2); // { 95, 30 }
for (let off = 0; off < bytes.length; off += packetBytes) {
  await transport.write(bytes.subarray(off, off + packetBytes));
  if (off + packetBytes < bytes.length) await new Promise(r => setTimeout(r, delayMs));
}

The runtime packages do exactly this inside print(); the loop is here for hosts that drive a transport themselves. Skipping it is the one way to make a chassis accept a job and print nothing.

Bitmap contract

Every encoder consumes LabelBitmap.data verbatim: ceil(width / 8) bytes per row, MSB first, 1 = dark. That is what renderImage produces, so there is no repacking step and no polarity flag to get wrong.