Practical integration guides for Indian SMS and WhatsApp messaging, written by the team that runs the gateway. Each one uses the real AvanceZone API and covers the India-specific parts most tutorials skip: DLT templates, sender ID rules, Unicode segment maths and retries that never double-send.
All guides call the same REST API. Authenticate with Authorization: Bearer YOUR_API_KEY (or an X-API-Key header), send JSON, and read JSON back.
| Endpoint | Purpose | Key fields |
|---|---|---|
POST /api/v2/sms/send | Send one SMS | sender_id, recipient, message, optional route, dlt_template_id, unicode, schedule_at |
POST /api/v2/sms/send-bulk | Same message to many numbers | recipients array, up to 1,000 per call |
GET /api/v2/sms/status/{id} | Delivery status of one message | Returns status: queued, sent, delivered or failed |
GET /api/v2/balance | Remaining credit | Balance in INR |
GET /api/v2/sender-ids · /templates | What your account may send | Approved headers and templates |
POST /api/v2/whatsapp/send | Send a WhatsApp message | to, template + params, or message inside the 24-hour window |
The base URL is https://whitelabled.securesmsc.com/api/v2. Calling the base URL without a key returns a machine-readable list of endpoints.
In India, code alone is not enough to send a business SMS. You also need a DLT-registered entity, an approved six-character sender ID and an approved template for every message type. Most "my SMS is not delivering" tickets come down to one of these. Our DLT registration guide covers the paperwork, and transactional vs promotional SMS explains which route each message belongs on.
Need OTPs specifically? The OTP SMS service runs on priority transactional routes. Each language guide above includes a safe OTP pattern: hashed codes, expiry, rate limits.
Sign up, and our team helps you through DLT so your first API call has an approved sender ID and template.
