Dual Authentication Patterns for Carrier Integration Middleware: Supporting SOAP and OAuth 2.0 During the 2026 Migration Wave
The 2026 carrier API migration wave is creating authentication chaos for multi-tenant carrier integration middleware. FedEx's final SOAP retirement deadline hits March 31, 2026, after which shipping with legacy web services ends worldwide. Meanwhile, USPS Web Tools APIs shut down on January 25, 2026. UPS already completed their