Introduction
This document provides a practical map to nShift’s API portfolio, helping you quickly identify the right integration path for ecommerce, shipping, or returns workflows. Whether you're embedding dynamic carrier options into your checkout, automating shipment creation and labelling, or onboarding new carriers and managing returns, each section links directly to official product documentation for your next step.
Designed for developers and operations teams, this signpost highlights core use cases, authentication methods, and guides you through seamless integration across nShift’s platform.
Picking the right API
- Use Checkout API for enriching an existing checkout experience, with multiple carriers, testing functionality and bespoke labelling. Also available as a widget / embedded service.
- Use Delivery API if you have an existing Delivery tenant.
- Use the headless Go API for platforms or marketplaces with complete customization.
- Use Returns API for full returns workflow where you want to customize the returns experience. Also available as a widget / embedded service.
- Use Ship API for enterprise shipping labels and full booking flows.
- Use Track API for post-purchase tracking and analytics with normalized carrier events where you want to customize the tracking experience. Also available as a widget / embedded service.
- Use Transsmart API for Transsmart multi-step booking and printing.
Checkout APl
Use this API to display rich carrier options, prices, pickup points, and delivery promises dynamically during your ecommerce checkout.
Get started here: Checkout API.
Delivery API
Manage shipments, manifests, prices, printing, alerts, and histories via REST endpoints. Suitable for tenants using api.unifaun.com for integrated shipment management.
Get started here: Delivery API.
Go API
A headless service designed for developers to build and integrate delivery functionality into platforms and marketplaces.
Get started here: Go API.
Returns API
Push order data, pull return orders and summaries, and manage refunds and customer UX integration.
Get started here: Returns API.
Ship API
Automate high-volume shipment creation, rate selection via Shipping Rules, label generation, EDI/manifests, and printing with this API. Ideal for enterprise shipping label management.
Get started here: Ship API.
Track API
Retrieve normalized tracking events, proof of delivery (POD), and shipment data across carriers.
Get started here: Track API.
Transsmart API
Use this API for creating, booking, and printing shipments within the Transsmart platform. Supports multi-step flows, SmartPrint printing, and shipment tracking.
Get started here: Transsmart Developer Center.
Authentication & environments (at a glance)
- Checkout API uses OAuth2 client credentials through the nShift Portal. See: Checkout Getting started, ShipmentData API
- Ship API supports API keys and OAuth2. See: Ship - Getting started, Find your API key
- Delivery API uses API keys and developer ID on api.unifaun.com. See: Delivery - Introduction
- Transsmart API uses Basic auth → JWT → Bearer token. See: Transsmart Developer Docs
- Returns API uses Basic auth with organization username/password. See: Push API, Pull API
- Go uses OAuth (clientId/secret + accountId). See: Go - Getting started.
Things that save you time
- Use Developer Tools in the Portal for live JSON requests/responses with Ship. See: Shipment Server integration guide
- Reference normalized tracking events across carriers: Normalized status names
- Use Transsmart BOOK/PRINT patterns when explicit control is needed: Transsmart Postman patterns
Notes for production hygiene
- Log request IDs and status transitions; build retries around immutable events, not assumptions
- Keep authentication scoped per API; rotate credentials via Portal policies
- Use test, beta, and acceptance environments before pushing production traffic