Production OAuth Monitoring for Carrier APIs: Building Authentication Alerts That Actually Work When UPS Changes Token Flows and FedEx Tightens Rate Limits
UPS migrated to OAuth 2.0 in August 2025. By February 3rd, 73% of integration teams reported production authentication failures. USPS followed with Web Tools API retirement in January 2026. January 2026: USPS is switching off the last of its Web Tools APIs (Version 3). Meanwhile, 52% of API breaches