SMS API Guide 2026: Send SMS Programmatically with DLT Support

If your product needs OTP, alerts, or transactional updates, an SMS API is the fastest way to automate delivery from your backend.

This guide from SMSGatewayCenter explains the full integration path:

Create account and generate API key

Configure sender ID

Send POST request to the send endpoint

Track delivery with transactionId and DLR

Built for India? The guide also covers DLT Entity ID, DLT Template ID, and common production mistakes that block delivery.