SMS verification endpoints are a prime target for attackers who drain credits or spam users. A recent Chinese engineering post outlines a four-phase defense: emergency shutdown, layered protection, business logic hardening, and post-incident review. The core technical stack includes Redis+Lua for distributed token bucket rate limiting, Bloom filters to pre-reject known risky phone numbers, and AOP annotations for per-user and per-IP limits. The article also covers edge-level controls at Nginx and gateway layers, plus circuit breakers using in-memory sliding windows. Key operational concerns like proxy IP pools and Redis failover are addressed, making this a realistic blueprint for production systems. For teams building or operating SMS services, this pattern is directly applicable and can be adapted to other high-cost API endpoints.
A practical guide to stopping SMS API abuse using layered defenses: Redis+Lua token buckets, Bloom filters, and AOP annotations across Nginx, gateway, and app tiers.