OTP SMS API · Live Live
OTP SMS API for Secure User Journeys
Use approved OTP templates for login, signup, transaction confirmation and account verification. As Alert21 Verify launches, move OTP generation and verification logic into a purpose-built verification API.
OTP Use Cases
- Login verification.
- Registration.
- Password reset.
- Transaction confirmation.
- Device verification.
- Sensitive profile changes.
SMS Delivery Mode
In the SMS-only phase, your system may generate the OTP and pass it as a template variable. Use short expiry windows and enforce attempt limits in your application.
Future Alert21 Verify Mode
Alert21 Verify should generate the OTP, store only protected verification state, apply expiry/resend/rate limits and provide a separate verification endpoint.
Protect OTP Traffic
- Rate limit by recipient and source/IP.
- Prevent excessive resend loops.
- Do not log OTP values in plaintext application logs.
- Detect unusual country/device patterns.
- Use idempotency where appropriate.
- Avoid revealing whether a user account exists through error messages.
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