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Delivery channel

WhatsApp OTP API for business

Add WhatsApp verification codes to signup, login, account recovery, and other user actions.

Quick Answer

Cascade WhatsApp OTP API lets a website or application send a one-time code to its own user. Successful delivery costs 3 credits, a standard code expires after 5 minutes, and integration uses server-side send and verify calls.

Summary

Cascade receives a backend request, delivers a six-digit OTP through WhatsApp, and provides an API to verify the code entered by the user.

Key Takeaways

  • WhatsApp is publicly available in Cascade.
  • Successful delivery costs 3 credits.
  • New accounts receive 1000 starting credits.
  • Keep the API key on the server only.
  • Cascade does not provide virtual numbers.

What a business gets

Cascade WhatsApp OTP provides a server-side flow for verifying a user's phone number. You do not need separate generation, delivery, and verification logic for each product interface.

The core capability includes a six-digit code, five-minute expiration, API verification, delivery responses, optional short links, and company history and balance in the dashboard.

This is outbound delivery to your own customers. Cascade does not rent temporary numbers for signups on third-party services.

Suitable use cases

Use case What the code confirms
Signup Control of the submitted number
Login Access to the delivery channel
Recovery A request to regain account access
Data change Phone, email, or security setting update
Sensitive action Confirmation inside your product
Short link Access to an order, payment, or confirmation screen

For high-risk operations, combine OTP with session checks, anti-fraud controls, or another factor.

Integration flow

The frontend calls your backend, and your backend calls Cascade. The Bearer token never enters browser or mobile code.

  1. The user enters a phone number.
  2. Your backend calls POST /api/otp/send with channel: whatsapp.
  3. Cascade delivers the code and returns its expiration.
  4. The user enters the code in your interface.
  5. Your backend calls POST /api/otp/verify.
  6. Your product continues only after success: true.
curl -X POST "https://cascade.kz/api/otp/send" \
  -H "Authorization: Bearer $CASCADE_API_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{"phone":"77001234567","purpose":"login","channel":"whatsapp"}'

See the send reference and documentation for complete fields and responses.

WhatsApp OTP pricing

Successful WhatsApp delivery costs 3 credits, with no subscription fee. A new company receives 1000 starting credits for integration testing.

Before scaling, measure successful delivery, time to code entry, resend share, and credits per verified user—not only request volume. Current packages and billing rules are on pricing.

The send endpoint accepts an optional link. Cascade creates a short URL and includes it with the code. This can return a user to an order, payment, or confirmation screen.

A link does not replace server-side risk checks. Set an expiration, validate destinations, and do not put sensitive data in the URL.

Limitations

  • WhatsApp must be accessible to the recipient.
  • Delivery depends on an external channel and cannot be guaranteed for every number.
  • The API key must stay off the client.
  • Send and verify require rate limits.
  • The UI must handle code expiration and resend cooldown.
  • Do not advertise SMS as active fallback; the public SMS provider is not live yet.

Products with different audience preferences can also use Telegram OTP through the same API.

Start a pilot

Create an account, obtain an API key, and test with consented internal phone numbers. Verify send, code validation, errors, countdown, and resend before enabling real user traffic.

Start free · View pricing · Open the API

FAQ

How much does WhatsApp OTP cost in Cascade?
Successful WhatsApp delivery costs 3 credits.
Can one message include a code and link?
Yes. Pass a URL in the send request and Cascade can shorten and include it in the message.
Is code verification a separate API call?
Yes. Call POST /api/otp/verify with the same phone and purpose.