carrier API token lifetime
OAuth Token Lifetimes Across 7 Carrier APIs
We measured OAuth access-token lifetimes for FedEx, UPS, DHL, and USPS carrier APIs — from 28 minutes to 8 hours — with sources and dates.
Sophie Martin
Integration engineer turned product manager. Built carrier adapters for parcel and freight across EU. Loves test harnesses and logs.
InPost API integration
InPost API Setup: From Sandbox Token to First Label
Step-by-step InPost API integration: get an OAuth 2.1 sandbox token, query locker locations, create a shipment, and generate your first label.
MercuryGate vs Descartes API
MercuryGate vs Descartes: Carrier API Access Compared
We test how MercuryGate and Descartes expose carrier connectivity to integrators — docs, auth, protocols — and say which fits direct API builds.
carrier API SDK
SDK Coverage Measured Across 12 Carrier APIs
We audited official SDK languages, maintenance activity, and open issues across 12 carrier APIs as of Sept 2026, with sources for every figure.
DPD return label API
DPD Return Labels via API: A Step-by-Step Guide
How to generate DPD return labels via API using the -RETURN parcel_type field, bearer-token auth, and rate limits — with a working failure case.
EasyPost vs Shippo
EasyPost vs Shippo for EU Cross-Border Labels
EasyPost vs Shippo tested for EU cross-border shipping: carrier coverage, customs docs, sandbox behavior, and 2026 pricing, with a scoped verdict.
carrier webhook retry policy
Webhook Retry Windows Across 7 Carrier APIs
We audited published webhook retry policies for FedEx, DHL, EasyPost, Shippo, ShipEngine, and Sendcloud, with intervals, attempt counts, and sources.
GLS API sandbox
Setting Up the GLS API Sandbox: First Label
Step-by-step guide to GLS parcel API sandbox setup: get MyGLS credentials, call CreateLabel, and generate your first test label.
AfterShip vs ClickPost
AfterShip vs ClickPost: Tracking API for EU Carriers
AfterShip vs ClickPost compared on EU carrier coverage, webhook retry design, and pricing transparency, with a verdict for European integration teams.
carrier API rate limits
Carrier API Rate Limits Across 9 Providers, 2026
Published carrier API rate limits for FedEx, DHL, UPS, ShipEngine, Shippo, Easyship and EasyPost, sourced from vendor docs as of August 2026.
carrier webhook signature verification
How to Verify Carrier API Webhook Signatures
Verify webhook signatures from EasyPost, Shippo, and DHL step by step, with HMAC code, exact header names, and the raw-body bug that breaks it.
EasyPost vs ShipEngine
EasyPost vs ShipEngine for EU Carrier Contracts
EasyPost vs ShipEngine compared on connecting your own GLS, DPD, and DHL contracts: rate limits, sandbox fidelity, webhooks, and pricing.