Circuit Breaker Pattern for OTP Services

OTP API outages cost you logins. A circuit breaker lets you fail fast and route to a fallback rather than queueing requests behind a slow upstream.

Why Circuit Breakers Matter for OTP

• OTP send is on the user critical path.
• Slow upstream = piled-up sessions.
• Fast failure + fallback > slow success.

Closed → Open → Half-Open

• Closed: normal traffic.
• Open: skip calls, fail fast or fallback for N seconds.
• Half-Open: probe with a small fraction; if probe succeeds, close.

Thresholds

• Trip on > 50% failure rate over 30s window with at least 20 requests.
• Open for 60s before half-open probe.
• Half-open probe: 5 requests, < 50% failure to close.

Fallback Strategy

• Voice OTP fallback.
• Secondary provider.
• Graceful degradation: queue with user-visible message.

Reference Implementation

import CircuitBreaker from 'opossum';

const breaker = new CircuitBreaker(callOtpApi, {
  errorThresholdPercentage: 50,
  resetTimeout: 60_000,
  rollingCountTimeout: 30_000,
  rollingCountBuckets: 10,
  volumeThreshold: 20,
});
breaker.fallback(() => callVoiceOtpFallback(phone));

FAQ

Combine with multi-region failover for a complete resilience story.