Resources
Short, practical notes — not a fake magazine with stock photos. For API shape, start at docs.
Principal entity, headers, templates, and PE-TM mapping — the checklist before you send OTP at scale.
How Meta’s conversation categories change cost and when to use authentication templates for OTP.
Rate limits, attempt caps, and channel fallback so Verify doesn’t become a billing incident.
When you need an API and routes — and when you only need WhatsApp CRM.
If you send SMS in India, TRAI DLT is not optional. Register the principal entity, get headers (sender IDs) approved, register content templates, and map your telemarketer (us) to the PE. OTP and other transactional traffic still needs matching templates. Promotional traffic has quieter hours and different headers. We help with this during onboarding — don’t go to production on a raw gateway and hope.
WhatsApp charges by conversation category. Utility covers post-purchase updates. Authentication is for OTP. Marketing is opt-in campaigns. Service windows behave differently once the user messages you. Mixing these up is how finance teams get surprise bills. Use authentication templates for Verify; don’t stuff OTPs into marketing templates.
Attackers will hit your signup endpoint to generate SMS to premium-rate or high-cost destinations. Cap attempts per phone and IP, shorten TTL, prefer WhatsApp or app-based factors where you can, and alert on sudden international spikes. Verify is designed for this pattern; a raw SMS send is not.
If three agents need to reply on WhatsApp, you want an inbox. If your backend needs to fire a million OTPs, delivery receipts, and retries, you want CPaaS. Converix is the latter, with chatbots as a layer on the channels — not a helpdesk that pretends to be a carrier.
