MSG91 API Integration
High-deliverability transactional SMS and OTP for Indian numbers with DLT support.
What MSG91 API integration does
MSG91 is built for Indian transactional messaging, and the reason to choose it over a global provider is deliverability on domestic numbers plus native handling of DLT — the TRAI-mandated registration regime that governs commercial SMS in India.
DLT is where most SMS integrations run into trouble. Sender headers and message templates must be registered before they will deliver, template content must match what was registered, and an unregistered variant fails silently rather than raising an obvious error. Our integration maps your registered DLT templates explicitly and validates outbound messages against them before sending, so a mismatch is caught at integration time rather than showing up as an unexplained drop in OTP delivery.
What teams build with it
High-volume OTP
Deliver verification codes to Indian numbers with the deliverability that login and checkout completion depend on.
Transactional SMS
Send order, payment and account notifications against registered DLT templates.
Bulk campaigns
Run promotional campaigns within DLT rules with delivery reporting.
Multi-provider fallback
Use MSG91 as the domestic primary with automatic failover to another provider.
Endpoints included
POST/msg91/v5/otpGenerates and sends an OTP to a mobile number.
Try it in the sandbox
https://sandbox.aeologic.io/msg91/v5/otp{
"mobile": "919928174455",
"template_id": "65f2a...",
"otp_length": 4
}What you need before we start
- An MSG91 account with API credentials
- DLT entity registration with approved sender headers
- DLT-approved templates for every message type you intend to send
- A webhook endpoint for delivery receipts
How we deliver it
- DLT template mapping and outbound validation
- Sandbox integration with delivery-receipt normalisation
- Failover configuration to a secondary provider
- Production rollout with delivery-rate monitoring per template
Related Communication integrations
MSG91 API integration — FAQs
Do you handle DLT registration?
We handle integration and template mapping against your registered headers and templates, and advise on the registration process. The DLT entity registration must be in your name as the sender.
What happens if a message does not match a registered template?
It fails to deliver, often silently. Our connector validates outbound content against the mapped template before sending so the mismatch is caught in development.
Can we combine MSG91 with WhatsApp?
Yes, and it is the common configuration — WhatsApp as primary with SMS fallback, or the reverse, through one send interface.
Ship MSG91 in days
Tell us your stack and we'll wire up MSG91 API integration for your team.
Talk to Aeologic