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Send and verify your first OTP →
Configure your delivery channel, keep an application key on your backend, and follow a complete send-and-verify example with explicit error handling.
DEVELOPER GUIDES
Build your first Sendrin integration.
Practical documentation for OTP verification, channel setup, notification requests, and delivery troubleshooting.
OTP channels, expiry, and resend limits
Learn the request fields for email, SMS, and WhatsApp, then handle verification attempts, expired codes, and resend cooldowns in your application.
Read the guide →Prepare a WhatsApp template integration
Review provider configuration, template parameters, and recipient consent before sending WhatsApp notifications through Meta Cloud API.
Read the guide →Configure your sending domain
Follow the domain setup guide to publish the required DNS records and configure a sender identity for your application.
Read the guide →Retry notification requests with idempotency
Use idempotency keys consistently when your backend retries a notification request, and understand what happens when the payload changes.
Read the guide →Investigate delivery attempts
Find a notification in delivery activity, inspect its processing history, and use the available tools to investigate failed sends.
Read the guide →Explore all guides and the full API reference. Head to the documentation ↗
INSTANT DEPLOYMENT
Choose a channel. Build your first integration.
One API, every channel, full delivery visibility. Start free, no credit card required.