Send business-critical SMS through a developer-friendly platform designed for approved DLT templates, consistent delivery status and scalable API integrations.
For approved templates, your application can submit the destination number, DLT Template ID and ordered variables. Alert21 can map the approved sender, Principal Entity and route details internally so your client integration remains concise.
{
"to": "919876543210",
"template_id": "1107161234567890123",
"variables": ["Amit", "2500", "TXN88991"]
}Alert21 should validate the number of supplied variables against the configured template, build the provider request and reject invalid requests before they become unnecessary billable attempts.
| State | Meaning |
|---|---|
| queued | Accepted and awaiting processing |
| processing | Being validated/routed |
| submitted | Accepted by provider/network layer |
| sent | Sent onward where supported |
| delivered | Delivery confirmation received |
| failed | Delivery failed |
| rejected | Rejected before/at submission |
| expired | Expired before confirmed delivery |
| undelivered | Network reported undelivered |
Quick answers to common questions about Alert21 SMS API, telecom compliance, and developer integration.
The Alert21 SMS API accepts standard HTTP POST requests with recipient mobile numbers, registered DLT template IDs, and dynamic message variables. It validates payloads, routes messages through optimal telecom gateways, and pushes delivery status back via webhooks.
Alert21 works with any programming language capable of sending HTTP requests, including Node.js, Python, PHP, Java, Go, C#, Ruby, and cURL commands.
Yes. Alert21 sends real-time, signed HTTP POST webhook callbacks directly to your application endpoints as soon as the carrier confirms delivery or failure.
Yes. Alert21 fully supports Unicode (UCS-2) messaging, enabling alerts and notifications in Hindi, Marathi, Bengali, Tamil, Telugu, and other regional scripts.
Start with DLT-ready SMS today on Alert21’s developer-first communication platform.