Build a Shipping Rates Plugin

app.post("/actions/shipping/get-rates", (req, res) => {
  verifyThreeUSignature(req);
  const { origin, destination, weight } = req.body;
  res.json({
    success: true,
    rates: [
      { id: "standard", name: "Standard",
        price: calculateRate(weight, destination),
        currency: "QAR", estimated_days: { min: 3, max: 7 } },
      { id: "express", name: "Express",
        price: calculateExpressRate(weight, destination),
        currency: "QAR", estimated_days: { min: 1, max: 2 } }
    ]
  });
});

app.post("/actions/shipping/create-shipment", (req, res) => {
  verifyThreeUSignature(req);
  const { order_id, rate_id, origin, destination } = req.body;
  const shipment = createWithCarrier({ rate_id, origin, destination });
  res.json({
    success: true,
    shipment: {
      id: shipment.id,
      tracking_number: shipment.tracking_number,
      tracking_url: shipment.tracking_url,
      label_url: shipment.label_url
    }
  });
});