Shipping Labels Example

Quick answer

Purchase a carrier label once, preserve the original returned artifact, and print it through a profile matching its format, size, resolution, and printer language. A reprint reuses the artifact; it must not purchase a second shipment.

type ShippingLabel = {
  shipmentId: string;
  carrierLabelId: string;
  format: "pdf" | "png" | "zpl";
  media: "4x6in";
  sha256: string;
  artifactUrl: string;
};

function printJob(label: ShippingLabel, printerId: string) {
  return {
    id: `${label.carrierLabelId}:${label.sha256}:${printerId}`,
    printerId,
    format: label.format,
    source: label.artifactUrl
  };
}

Validate remote URLs server-side or download through an authorized service; do not let arbitrary browser input make a local runtime fetch internal resources. Preserve the carrier artifact and checksum for audit.

Portix’s supported formats, URL policy, and submit call aren’t documented yet.

Verify

• Printed dimensions are exactly 4 × 6 inches where required.
• Barcode scans and human-readable tracking match.
• Retry does not repurchase postage.
• Void and reprint are distinct audited actions.
• PDF scaling is disabled when appropriate.