Shippo

// Shippo creates shipping labels for UCP-initiated orders.
// Call after UCP checkout confirms to rate-shop and purchase a label.

import Shippo from 'shippo';
const shippo = new Shippo({ apiKeyHeader: process.env.SHIPPO_API_KEY });

// Get rates for the order
const shipment = await shippo.shipments.create({
  addressFrom: merchantAddress,
  addressTo: {
    name: consumerName,
    street1: shippingAddress.line1,
    city: shippingAddress.city,
    state: shippingAddress.state,
    zip: shippingAddress.zip,
    country: 'US',
  },
  parcels: [{ length: '10', width: '8', height: '4', distanceUnit: 'in',
               weight: '2', massUnit: 'lb' }],
  async: false,
});

// Select the cheapest rate and purchase the label
const cheapestRate = shipment.rates.sort((a, b) => a.amount - b.amount)[0];
const transaction = await shippo.transactions.create({
  rate: cheapestRate.objectId,
  labelFileType: 'PDF',
  async: false,
});