Secure Printing

Data Border's Print API completes the secure label workflow. After generating a label via the Label Proxy, use the Print API to send the unredacted label directly to a printer—bypassing your WMS entirely.

The Complete Flow

sequenceDiagram
    participant WMS
    participant ADB
    participant S3 as S3 Storage
    participant DeviceHub as Device Hub
    participant Printer

    Note over WMS: Step 1: Generate label
    WMS->>ADB: POST /api/label-proxy/forward
    ADB->>WMS: {shipment_id, documents: [{uuid}]}
    
    Note over WMS: Step 2: Request print
    WMS->>ADB: POST /api/print/send<br/>{shipment_id, label_uuids}
    ADB->>ADB: Lookup shipment
    ADB->>S3: Fetch unredacted labels
    S3->>ADB: Return label PDFs
    ADB->>DeviceHub: POST print job
    DeviceHub->>Printer: Print label
    Printer->>DeviceHub: Acknowledge
    DeviceHub->>ADB: Job complete
    ADB->>ADB: Increment print count
    ADB->>WMS: {status: "sent", is_reprint: false}

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Notice that your WMS never touches the actual label file—it only references it by UUID.

Setting Up Device Hub

Device Hub is a local print server that runs in your warehouse. Data Border sends print jobs to it over HTTPS.

Device Hub Configuration

Each tenant in Data Border can have a Device Hub URL configured:

Tenant Configuration:
- deviceHubHost: https://devicehub.warehouse.local:8443

Contact your Data Border administrator to configure your Device Hub URL.

Network Requirements

Device Hub must be accessible from Data Border:

HTTPS - TLS encryption required
Authentication - Device Hub should authenticate Data Border requests
Firewall - Allow inbound from Data Border's IP ranges

Sending Print Jobs

Request Format

curl -X POST https://adb.example.com/api/print/send \
  -H "Content-Type: application/json" \
  -H "x-seller-access-token: YOUR_SELLER_TOKEN" \
  -H "x-amazon-token-secret: YOUR_TOKEN_SECRET" \
  -d '{
    "shipment_id": "ship_abc123def456",
    "printer_type": "label",
    "printer_id": "warehouse-1-zebra",
    "label_uuids": ["550e8400-e29b-41d4-a716-446655440000"]
  }'

Request Fields

Field	Type	Description
`shipment_id`	string	Data Border shipment ID from label generation
`printer_type`	string	`"label"` (thermal) or `"laser"`
`printer_id`	string	Target printer identifier in Device Hub
`label_uuids`	array	UUIDs of documents to print

Response

First Print:

{
  "success": true,
  "data": {
    "status": "sent",
    "shipment_id": "ship_abc123def456",
    "documents_sent": 1,
    "print_count": 1,
    "is_reprint": false
  }
}

Reprint:

{
  "success": true,
  "data": {
    "status": "sent",
    "shipment_id": "ship_abc123def456",
    "documents_sent": 1,
    "print_count": 2,
    "is_reprint": true,
    "warning": "Reprint detected. First printed: 2024-01-15T10:30:00.000Z"
  }
}

Reprint Detection

Data Border tracks how many times each shipment's labels have been printed:

First print: print_count: 1, is_reprint: false
Subsequent prints: print_count: N, is_reprint: true, includes warning

This creates an audit trail for reprints, which can indicate:

Legitimate reprints (printer jammed, label damaged)
Potential fraud (duplicate labels)
Process issues (labels being wasted)

Your WMS can use is_reprint to:

Show warnings to warehouse staff
Require supervisor approval for reprints
Log reprint reasons in your system

Error Handling

Shipment Not Found

{
  "is_adb_error": true,
  "success": false,
  "error": {
    "message": "Shipment not found",
    "details": "No shipment found with id ship_abc123def456"
  }
}

Device Hub Not Configured

{
  "is_adb_error": true,
  "success": false,
  "error": {
    "message": "Device Hub not configured for this tenant",
    "details": "Contact your administrator to configure the Device Hub host"
  }
}

Invalid Label UUIDs

{
  "is_adb_error": true,
  "success": false,
  "error": {
    "message": "Invalid label UUIDs",
    "details": "The following UUIDs are not part of this shipment: 550e8400-..."
  }
}

Device Hub Unreachable

{
  "is_adb_error": true,
  "success": false,
  "error": {
    "message": "Device Hub communication failed",
    "details": "Connection timeout after 30000ms"
  }
}

Printer Types

Label Printers (`"label"`)

Thermal printers like Zebra, DYMO, or Brother:

Typically 4x6" or 4x8" labels
ZPL or EPL format
Direct thermal or thermal transfer

Laser Printers (`"laser"`)

Standard office printers:

Letter or A4 paper
PDF format
For packing slips, invoices, customs forms

Best Practices

Validate UUIDs Before Printing

Store the documents array from label generation and validate before print requests:

// After label generation
const labelResponse = await generateLabel(orderData);
const shipmentId = labelResponse.shipment_id;
const documentUUIDs = labelResponse.documents.map(d => d.uuid);

// Store in your database
await saveShipment({
  orderId: orderData.orderId,
  shipmentId,
  documentUUIDs
});

// Before printing
const shipment = await getShipment(orderId);
const validUUIDs = documentUUIDs.filter(
  uuid => shipment.documentUUIDs.includes(uuid)
);

Handle Reprints Appropriately

const printResponse = await sendPrintJob(shipmentId, uuids);

if (printResponse.is_reprint) {
  logger.warn({
    type: 'print',
    shipmentId,
    printCount: printResponse.print_count,
    firstPrinted: printResponse.warning
  }, 'Label reprint detected');
  
  // Optionally require confirmation
  if (printResponse.print_count > 2) {
    await requireSupervisorApproval(shipmentId);
  }
}

Configure Timeouts

The default Device Hub timeout is 30 seconds. For large print jobs or slow networks, consider:

Printing labels individually rather than in batches
Implementing retry logic with exponential backoff
Monitoring Device Hub response times

End-to-End Example

Here's the complete workflow for shipping an Amazon order:

// 1. Generate label with placeholders
const labelResponse = await fetch('/api/label-proxy/forward', {
  method: 'POST',
  headers: {
    'x-seller-access-token': sellerToken,
    'x-amazon-token-secret': tokenSecret,
    'x-original-url': 'https://api.easypost.com/v2/shipments',
    'x-amazon-order-id': amazonOrderId,
    'x-unique-shipment-id': `${orderId}-${Date.now()}`
  },
  body: JSON.stringify({
    shipment: {
      to_address: {
        name: '{{ship_to_name}}',
        street1: '{{ship_to_address1}}',
        city: '{{ship_to_city}}',
        state: '{{ship_to_state}}',
        zip: '{{ship_to_zip}}',
        country: '{{ship_to_country}}'
      },
      from_address: warehouseAddress,
      parcel: packageDimensions
    }
  })
});

const { shipment_id, documents } = await labelResponse.json();

// 2. Store shipment info in your WMS
await saveShipment({
  orderId,
  amazonOrderId,
  shipmentId: shipment_id,
  trackingNumber: scrubbed_response.tracking_code,
  documentUUIDs: documents.map(d => d.uuid)
});

// 3. Print the label
const printResponse = await fetch('/api/print/send', {
  method: 'POST',
  headers: {
    'x-seller-access-token': sellerToken,
    'x-amazon-token-secret': tokenSecret
  },
  body: JSON.stringify({
    shipment_id: shipment_id,
    printer_type: 'label',
    printer_id: workstationPrinter,
    label_uuids: documents.map(d => d.uuid)
  })
});

// 4. Label prints at workstation
// Your WMS never saw the customer address!

Next Steps

Audit & Compliance

Understand the complete audit trail.

API Reference

Complete Print API documentation.