Webhook Callbacks
SBS TELECOM supports HTTP webhook callbacks for delivery receipts (DLRs) and inbound (MO) messages. Webhooks allow your application to receive real-time notifications without polling the API.
Delivery Receipt Webhooks
When a message delivery status changes, we POST a JSON payload to your configured webhook URL:
POST https://your-app.com/webhooks/sms-dlr
Content-Type: application/json
{
"id": "msg_01HXZ9K...",
"to": "+447911123456",
"status": "delivered",
"error_code": null,
"delivered_at": "2025-01-01T12:00:05Z"
}Inbound Message Webhooks
When a recipient replies to your SMS, we POST the inbound message to your MO webhook URL:
{
"from": "+447911123456",
"to": "SBSTEL",
"text": "STOP",
"received_at": "2025-01-01T12:05:00Z"
}Webhook Security
All webhook payloads include an HMAC-SHA256 signature in the X-SBS-Signature header for verification. Validate this signature in your webhook handler to ensure requests originate from SBS TELECOM.
Retry Policy
If your endpoint returns a non-2xx response, we retry up to 5 times with exponential backoff over 24 hours.