API Integration

API (Application Programming Interface) integration allows shipping software to communicate directly with carrier systems in real-time. This enables automated rate quotes, label creation, tracking updates, and more without manual data entry.

How Shipping APIs Work

Basic Flow

1. Your software sends request (e.g., “get rates for this package”)
2. Request travels to carrier’s API server
3. Carrier processes and responds
4. Response contains rates, labels, tracking, etc.
5. Your software displays/uses the information

Example: Creating a Shipment

Your System → Carrier API:
"Ship 5 lb box from NYC to LA"

Carrier API → Your System:
"Label URL, tracking #123456, cost $15.50"

Common Shipping API Functions

Rating

• Get shipping rates
• Compare services
• Calculate delivery dates
• Apply discounts

Shipping

• Create shipments
• Generate labels (PDF, ZPL, PNG)
• Schedule pickups
• Void/cancel shipments

Tracking

• Get current status
• Receive status webhooks
• Proof of delivery
• Exception notifications

Other Functions

• Address validation
• Service availability
• Pickup requests
• Customs documentation

Major Carrier APIs

UPS

• UPS Developer Kit
• Comprehensive functionality
• Account required
• Good documentation

FedEx

• FedEx Web Services
• REST and SOAP options
• Wide feature coverage
• Developer sandbox

USPS

• Web Tools APIs
• Free to use
• Requires registration
• Some limitations

DHL

• DHL Express APIs
• International focus
• Multiple services
• Account required

Multi-Carrier Shipping APIs

Instead of integrating each carrier separately, aggregator APIs provide single integration:

Don’t need an API? If you just want to compare rates and ship packages without building integrations, I’d Ship That provides instant multi-carrier comparison through a simple web interface—no coding required.

Benefits of Aggregators

• Single integration point
• Consistent data format
• Multi-carrier rate shopping
• Unified tracking
• Easier maintenance

API Integration Benefits

Automation

• No manual label creation
• Automatic tracking updates
• Rate shopping without research
• Batch processing capability

Accuracy

• Addresses validated
• Rates always current
• Fewer manual errors
• Consistent formatting

Speed

• Real-time responses
• Instant label generation
• Immediate tracking
• Fast checkout experience

Scalability

• Handle high volumes
• Add carriers easily
• Grow without manual bottlenecks
• Multiple channels supported

Building API Integrations

Direct Carrier Integration

Pros:

• No middleman fees
• Full feature access
• Direct relationship

Cons:

• Multiple integrations needed
• Maintenance burden
• Different formats per carrier

Using Aggregators

Pros:

• Single integration
• Faster implementation
• Carrier switching easy

Cons:

• Per-transaction fees
• May lack some features
• Additional dependency

API Integration Checklist

Technical Requirements

• API credentials (keys, tokens)
• Development environment
• Testing sandbox access
• Error handling setup
• Rate limiting compliance

Business Setup

• Carrier account(s)
• Shipping origins configured
• Default services selected
• Pricing/margins configured
• Label printer setup

Testing

• Rate requests work
• Labels generate correctly
• Tracking updates receive
• Error scenarios handled
• Production credentials secure

Common API Challenges

Rate Limiting

• APIs limit requests per second/minute
• Implement retry logic
• Cache where appropriate
• Batch requests when possible

Error Handling

• API downtime happens
• Have fallback plans
• Log errors for debugging
• Alert on critical failures

Versioning

• APIs update over time
• Monitor deprecation notices
• Test updates before production
• Plan migration time

API Security Best Practices

1. Secure credentials - Don’t expose API keys in code
2. Use HTTPS - Always encrypted connections
3. Implement authentication - OAuth, API keys properly
4. Validate responses - Don’t trust input blindly
5. Monitor usage - Detect unusual patterns
6. Rotate keys - Regular credential updates