# Pending Authentication Flow
***
**Characteristics:**
* Card enrolled in 3D Secure
* Issuer requires additional cardholder verification
* User interaction required
**Flow Steps:**
```
1. Setup → Get authentication tokens
2. Capture → Collect device data automatically
3. Enroll → 3D Secure check: CHALLENGE REQUIRED
4. Challenge → Display authentication modal to user
5. User Action → Complete OTP, biometric, or other verification
6. Validation → Confirm challenge completion
7. Result → Authentication successful (ECI: 06 for VISA/AMEX, 02 for Mastercard) or authentication failed
8. Authorization → Process payment (if successful)
9. Complete → Transaction finalized
```
**API Responses:**
* Setup: `status: "Completed"`
* Enroll: `status: "Pending_authentication"`
* Validation: `status: "Authentication_successful"` or `status: "Authentication_failed"`
**Challenge Types:**
* SMS OTP verification
* Mobile app push notification
* Biometric authentication
* Security questions
* Hardware tokens
**Implementation Notes:**
* Use Cardinal Commerce SDK for challenge display
* Handle challenge timeout scenarios
* Provide fallback authentication methods
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://firstoken.gitbook.io/api-docs/api-reference/risk/payer-authentication-3d-secure/detailed-flow-scenarios/pending-authentication-flow.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.