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.

For detailed installation and setup instructions, see the Device Hub documentation. You can also download the Device Hub client applications from devices.shipstream.io/downloads.

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.