Send OTP Codes Over WhatsApp With the Telnyx Verify API

curl -X POST https://api.telnyx.com/v2/verifications \
 -H "Authorization: Bearer YOUR_TELNYX_KEY" \
 -H "Content-Type: application/json" \
 -d '{
 "phone_number": "+15551234567",
 "verify_profile_id": "YOUR_VERIFY_PROFILE_ID",
 "type": "whatsapp"
 }'

curl -X POST https://api.telnyx.com/v2/verifications/by_phone_number/+15551234567/actions/verify \
 -H "Authorization: Bearer YOUR_TELNYX_KEY" \
 -H "Content-Type: application/json" \
 -d '{
 "code": "12345"
 }'

Replace +15551234567 with the phone number used in the original request. Replace 12345 with the code submitted by the user.

A successful response means the code is valid. If the code is incorrect or expired, Telnyx returns an error response. That is the core integration. One request sends the OTP. One request verifies it.

Track delivery with webhooks

Telnyx can send webhook events to your configured endpoint as the verification progresses. These events help your app show status, store audit logs, and start fallback rules when a message fails or expires.

For example, if WhatsApp delivery fails, your application can fall back to SMS without requiring the user to restart the verification process. Plan those rules before launch. The SMS 2FA, 2FA guide, and number verification resources cover common policy choices.

Choose the right verification channel

Use WhatsApp when the user has WhatsApp and expects messages there. Use SMS when reach is the main requirement. Use voice when a text-based path fails or the user needs an audible code.

Use the Telnyx SMS API when your verification stack also needs standalone global messaging. It supports 10DLC, toll-free, and shortcodes. Use the Telnyx Voice API when a fallback must call the user. It supports programmable voice with WebSocket support.

You switch channels by changing a single field in the request body. That makes it easier to build flexible verification flows. Try WhatsApp first. Fall back to SMS if needed. Use voice for users who cannot receive text-based messages.

Why Telnyx for WhatsApp OTPs

Without Telnyx Verify, sending OTPs through WhatsApp means working directly with the WhatsApp Business API. You manage templates, handle delivery events, and maintain additional integration logic. Telnyx abstracts that complexity.

Try the example app

Telnyx provides a working Python Flask example that shows how to send, verify, and track WhatsApp OTPs. Clone the whatsapp-verify-otp-python example from GitHub.

The example includes routes for sending the OTP, validating the submitted code, receiving verification webhooks, and environment variable configuration for your Telnyx API key and Verify Profile ID.

Getting started

To start sending OTPs over WhatsApp with Telnyx:

You can find the full Verify API documentation at developers.telnyx.com.

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