Planned
Alert21 Verify
OTP generation and verification workflows
Dedicated API page publishes when production-ready.Home
Communication APIs Built for Every Business Alert
Alert21 is a unified communication API platform for businesses that need reliable alerts, verification and customer notifications. Start with our DLT-ready SMS infrastructure and scale toward every channel through one developer-first platform.
SMS API, Email API and 24x7 Website Monitoring are live on Alert21. Additional communication channels will activate only after production readiness is confirmed.
01Application
02Alert21 API
03Validation
04Queue
05Provider
06Recipient
DLR / signed webhook returns delivery state to your application
EVERY ALERT. ONE API.
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SMS API, Email API and 24x7 Website Monitoring are live on Alert21. Additional communication channels will activate only after production readiness is confirmed.
One Platform for Business-Critical Alerts
Alert21 helps businesses send and monitor critical customer and system alerts through developer-friendly products. Use live SMS API, Email API and Website Monitoring today, and expand into additional channels as they become production-ready.
- API-first integration for SaaS, fintech and enterprise systems.
- DLT-aware SMS workflows for India.
- Real-time message lifecycle and delivery callbacks.
- Reseller, white-label and enterprise-ready business architecture.
- Multi-provider and international routing ready at the platform layer.
Send Your First SMS with Three Inputs
Keep the client integration simple: send the destination number, approved DLT Template ID and ordered template variables. Alert21 maps the approved sender, principal entity, telemarketer/provider and route configuration behind the API.
{
"to": "919876543210",
"template_id": "1107161234567890123",
"variables": ["Amit", "2500", "TXN88991"]
}No provider-specific credentials in your customer integration. No need to send the full approved template every time.
Product family
Communication Products
SMS, Email and Website Monitoring are live now. Future channels stay explicitly planned or future until production readiness is confirmed.
Live
Alert21 SMS
Transactional, service, promotional, OTP, Unicode and bulk SMS
Explore SMS APILive
Alert21 Website Monitoring
Monitor websites 24x7, track uptime and response time, watch SSL expiry, and get instant alerts through Email, SMS, WhatsApp and In-App notifications.
Explore Website MonitoringPlanned
Alert21 WhatsApp
Official business messaging APIs
Dedicated API page publishes when production-ready.Live
Alert21 Email
Transactional email for OTPs, payments, orders, invoices, account alerts and system notifications. Configure verified sending identities, templates, API sending, logs and billing from Alert21.
Explore Email APIPlanned
Alert21 Push
Web, Android and iOS push
Dedicated API page publishes when production-ready.Planned
Alert21 Voice
Voice OTP, reminders and automated calls
Dedicated API page publishes when production-ready.Future
Alert21 RCS
Rich business messaging
Dedicated API page publishes when production-ready.Future
Alert21 Flow
Cross-channel workflow and fallback orchestration
Dedicated API page publishes when production-ready.Why Alert21
Compliance as a Feature (The DLT Moat)
India’s DLT framework can be a bottleneck. We turned it into an asset. Alert21 natively abstracts TRAI DLT registration, Principal Entity mapping, and template validation directly inside the API flow, ensuring compliance-ready, low-latency transactional SMS delivery without the operational headache.
Developer-First
Use stable REST endpoints, consistent responses, webhooks, logs and code examples designed to reduce integration effort.
DLT-Aware by Design
Map approved headers, templates and Principal Entity information to client accounts and validate messaging before provider submission.
Built for Reliability
The Alert21 platform is designed around queued processing, controlled retries, provider adapters, monitoring and normalized delivery states. Confirm current production capabilities and service commitments during onboarding.
Ready to Grow
The same integration philosophy can support future communication channels and international routes without forcing customers to rebuild their applications.
Built for Modern Industries
| Industry | Typical Alerts |
|---|---|
| Fintech | OTP, transaction, settlement, KYC and security alerts |
| Banking & Payments | Account activity, payment status and verification |
| SaaS | Login, billing, onboarding and system notifications |
| E-commerce | Order, shipment, return and payment updates |
| Education | Attendance, fee, exam and emergency alerts |
| Travel & Hospitality | Booking, check-in, schedule and payment alerts |
| Healthcare | Appointment and operational notifications |
| Logistics | Pickup, dispatch, tracking and delivery notifications |
Built for Developers
From API Request to Delivery Status.
Integrate using documented endpoints, keep credentials server-side, store the Alert21 Message ID, and receive signed delivery webhooks back into your application.
Become an Alert21 Partner
Grow a messaging business with reseller and white-label capabilities designed around customer management, pricing control, wallet operations, reporting and API access.
Designed for India. Architected for Global Expansion.
Alert21 starts with India’s DLT-ready SMS requirements, while the underlying architecture is designed to add country-specific routes, sender rules, consent requirements and future channels as the platform expands internationally.
Country and route availability is confirmed only after commercial, technical and compliance readiness checks. Contact Sales for the current coverage available to your account.
EVERY ALERT. ONE API.
Build notification journeys that begin with SMS today and can expand across channels tomorrow — without changing the way your application thinks about business events.
Direct Answers
Frequently Asked Questions
Quick answers to common questions about Alert21 SMS API, telecom compliance, and developer integration.
What is Alert21?
Alert21 is a developer-first communication API platform operated by Scriza Private Limited in India. It provides a unified REST API for DLT-compliant transactional SMS, low-latency OTP delivery, promotional messaging, and real-time delivery webhooks.
How is Alert21 different from the networking error "Alert 21"?
Alert21 (alert21.in) is an enterprise messaging and CPaaS API platform. It is completely distinct from the networking and cybersecurity protocol error known as "Encrypted Alert (21)" or "TLS Alert 21", which occurs during encrypted TLS/SSL handshake terminations.
Is Alert21 compliant with TRAI DLT mandates in India?
Yes. Alert21 supports DLT-compliant SMS workflows for India by validating the customer’s registered Principal Entity, approved sender header and content template before submission. The platform targets zero preventable carrier rejections caused by DLT configuration mismatches; other operator, route or recipient conditions can still affect acceptance and delivery.
What is the delivery latency for Alert21 OTP SMS?
Under normal operating conditions, Alert21 returns an API submission response within a maximum of 5 seconds and maintains a 99.9% successful API response rate. This measures the API response, not guaranteed handset delivery time; final SMS delivery depends on the telecom operator, route, DLT configuration and recipient network conditions.
How do I start integrating the Alert21 SMS API?
Open the Alert21 application to create or access your account, then follow the SMS quickstart to configure a server-side API key and an approved DLT template. Contact the Alert21 team when your account, route or DLT onboarding requires assistance.
EVERY ALERT. ONE API.
Turn your next business event into a traceable alert.
Start with DLT-ready SMS today on Alert21’s developer-first communication platform.