LabelStudio JS Client

Small JavaScript client for your custom LabelStudio service.

Install

npm i labelstudio-js-client

Quick Start

import LabelStudio from 'labelstudio-js-client';

await LabelStudio.configure({
  baseUrl: 'http://localhost:3966',
  preferredPrinters: ['DYMO LabelWriter 450', 'DYMO']
}).init();

const printers = await LabelStudio.getPrinters();
LabelStudio.setPrinter(printers[0]);
LabelStudio.setLabel('dymo.address.30252');

const label = new LabelStudio.Label();
label
  .addText('Order #100045', {
    left: 60,
    top: 70,
    width: 500,
    height: 80,
    fontSize: 40,
    textAlign: 'left',
    autoFit: false
  }).done()
  .addText('Property of SecureErase, LLC', {
    left: 150,
    top: 220,
    width: 540,
    height: 70
  }).align('center').autoFit(true, { width: 540, height: 70 }).done()
  .addBarcode('0192-XY-445901').dimensions(780, 190).at(55, 130).done()
  .addQrCode('https://example.com/track/INV-100045').size(240).at(40, 20).done();

await LabelStudio.print(label, { copies: 2 });

API

• LabelStudio.configure(options)
• LabelStudio.init()
• LabelStudio.getPrinters()
• LabelStudio.getLabels()
• LabelStudio.setPrinter(name)
• LabelStudio.setLabel(labelId)
• LabelStudio.print(labelOrDesign, options?)
• LabelStudio.printBulk(labelsOrDesigns, options?)
• LabelStudio.renderTemplate(template, data)
• LabelStudio.convertJsonToJs(payload, options?)
• new LabelStudio.Label()

new LabelStudio.Lable() is also supported as an alias.

Builder Methods

Element builder methods work for text/barcode/qr/image and return to label with .done():

• .at(left, top)
• .size(value)
• .dimensions(width, height)
• .scale(x, y?)
• .color(fill)
• .font(family)
• .weight(fontWeight)
• .align('left' | 'center' | 'right')
• .autoFit(enabled, { width?, height? })
• .options(object)

Label methods:

• addText(text, options?)
• addBarcode(data, options?)
• addQrCode(data, options?)
• addImage(src, options?)
• addObject(object)
• toJSON()

JSON to JS Converter

Convert a JSON payload into builder-style JavaScript:

const payload = {
  printer: 'DYMO LabelWriter 450',
  label: 'dymo.address.30252',
  objects: [
    {
      type: 'textbox',
      text: 'Order #100045',
      left: 60,
      top: 70,
      width: 500,
      height: 80,
      fontSize: 40,
      textAlign: 'left',
      autoFit: false
    },
    { type: 'barcode', barcodeType: 'code128', barcodeData: '0192-XY-445901', left: 55, top: 130 }
  ]
};

const code = LabelStudio.convertJsonToJs(payload, { includePrintCall: true });
console.log(code);

Error Handling

Common failure cases now throw explicit errors:

• ServiceUnavailableError: backend service is not reachable.
• DiscoveryError with code NO_PRINTERS: no printers discovered.
• DiscoveryError with code NO_LABELS: no labels discovered.