Multi-Tenant Rate Limiting Coordination for Carrier Integration: Preventing Cross-Tenant Cascade Failures During the 2026 API Migration Crisis
USPS's new APIs enforce strict rate limits of approximately 60 requests per hour, down from roughly 6,000 requests per minute without throttling in the legacy system. USPS Web Tools shut down on January 25, 2026, and FedEx SOAP endpoints retire on June 1, 2026. For enterprise teams