W~2s · highest open rate
WhatsApp OTP: template messages or reverse verification.
Send template codes through Meta Cloud API, or drop the code-entry step entirely with reverse OTP.
How reverse OTP works
1
Generate the link
The API returns a wa.me action_url carrying a single-use token.
2
User sends it
One tap sends the prefilled message from WhatsApp — no typing a code.
3
Number matches
The sender's number is matched against the token and verification completes.
4
Webhook
A verified event hits your webhook; you can open the session.
$ curl -X POST https://api.kolayotp.com/api/v1/otp/send \
-H "Authorization: Bearer kotp_live_..." \
-d '{"channel":"whatsapp","mode":"reverse",
"recipient":"+905551234567"}'
{
"id": "otp_8Lm2xR",
"mode": "reverse",
"action_url": "https://wa.me/905XXXXXXXXX?text=KOTP-8Lm2xR",
"status": "awaiting_inbound",
"expires_at": "2026-09-11T09:51:00Z"
}Channel specifications
ProviderMeta Cloud API
Typical latency~2s
Unit price₺0.42 / OTP
Reverse OTPSupported
FallbackSMS → Email
Template approvalManaged in panel
Send your first OTP in five minutes.
No credit card. Start on a sandbox key and switch to live when you're ready.