OTP & Transactional
Priority routing to the fastest carrier, automatic retry and failover, idempotency keys that stop double-sends, and WhatsApp fallback when SMS is slow.
5 articles
Setting up the OTP API
One endpoint to send, one to verify. The API handles code generation, expiry, attempt limits, and resend cooldowns automatically. Most teams go live in under 30 minutes.
4 min readUpdated 11 Mar 2026How OTP priority routing works
We route each OTP through the fastest live carrier path for that specific destination at that specific moment.
4 min readUpdated 12 Mar 2026OTP retry and failover logic
If the primary route fails, we fail over to the next-fastest one before your user even sees a delay.
3 min readUpdated 13 Mar 2026Idempotency keys for OTP sends
Prevent duplicate OTPs when your app retries. Pass a UUIDv4 Idempotency-Key header on /v2/otp/send and we return the original response without triggering a new send.
2 min readUpdated 14 Mar 2026Using WhatsApp as a fallback for SMS OTP
If SMS is slow or fails, the same OTP is automatically delivered over WhatsApp — usually in under a second. You pay only for the channel that successfully delivers the code.
3 min readUpdated 15 Mar 2026
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