Why does my Verify API request fail when the Silent Authentication channel is not the first channel on the workflow?

Symptom

Receive 422 API response "Channel silent_auth must be the first channel in the workflow" when using multiple channels, and Silent Authentication is not the first channel on the Verify API request workflow.

Applies To

• Verify API
• Silent Authentication

Resolution

If using multiple channels, Silent Authentication must be the first channel in the workflow.

Cause

Silent Authentication leverages the mobile device’s Subscriber Identity Module (SIM) to verify the user's identity without requiring manual input. Given this inherent design, placing Silent Authentication as a secondary channel (such as following SMS) can lead to inconsistencies in the user experience.
For instance, if the user is unable to receive the SMS code due to a technical issue, Silent Authentication will automatically trigger after the channel_timeout period. Since this process occurs without user interaction, it may appear unexpected or confusing to the end user. Therefore, careful consideration should be given to the channel sequencing to ensure a seamless authentication flow.

Additional Information

For more information, see the Verify API Silent Authentication guide.