OTP & Transactional
OTP & Transactional APIs
Mission-critical authentication and alerts on infrastructure built for uptime — with automatic SMS → WhatsApp → Voice fallback so no OTP goes undelivered.
Key features
What you get with OTP & Transactional
Sub-second OTP delivery with multi-channel fallback
- Sub-second OTP delivery on high-priority transactional routes
- Automatic fallback chain: SMS → WhatsApp → Voice
- 99.9% uptime SLA with multi-operator redundancy
- Built-in OTP generation, verification and expiry handling
- Rate limiting and fraud/abuse protection per number
- Simple REST APIs with cURL, PHP, Python, Node.js and Java samples
- Delivery webhooks with signed payloads
- Sandbox environment and detailed developer docs
OTP & Transactional
verified business
- CRSOTP482913 is your verification code. Valid for 10 minutes. Do not share.
- SMS undelivered → WhatsApp attempted → delivered in 0.8s
- CRSOTPRs.12,499 debited from A/c XX4412 towards ORDER48219.
Sample messages rendered as your customers see them.
How it works
From onboarding to first campaign
A dedicated account manager runs each step with your team.
- 1
Grab an API key
Create a project in the console and issue scoped API keys.
- 2
Call the send endpoint
One POST request sends the OTP and returns a request ID.
- 3
Verify the code
Post the user's input to /verify — we handle expiry and retries.
- 4
Listen to webhooks
Receive delivery and fallback events on your endpoint in real time.
Use cases
Where OTP & Transactional earns its keep
- Login and signup verification for apps and portals
- Payment and high-value transaction confirmation
- Password reset and profile change alerts
- Delivery-agent OTP handover at the doorstep
- KYC and onboarding verification flows
FAQ
Questions we get asked
Explore more
Pair it with another channel
Start your first campaign today — get 100 free credits
No setup fee, no commitment. Our team configures your DLT headers and templates while you test delivery on live routes.