API Documentation

Build faster, smarter workflows with our robust APIs—designed to connect your end-to-end  shipping process, from order to doorstep.

ShipStation API

High-performing, standalone API that allows you to integrate once to access 200+ carriers, automate fulfillment, manage returns, and grow with confidence.

View Endicia API (Legacy) Documentation
API Status
Libraries & SDKs
Setup Carriers
Calculate Costs

ShipStation Companion API

Consolidate orders, print discounted labels, track shipments, and sync inventory in real time–all while plugging directly into your shipping UI.

Over 100,000 marketplaces, ERPs, and fulfillment systems rely on the Companion API to connect seamlessly with ShipStation and power their shipping.

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