Use this sequence diagram alongside our EMV 3DS2 Recipes for a complete, hands-on implementation guide.
This diagram details the process of handling 3D Secure card payments via the N-Genius Online Direct API, outlining each step, crucial API calls, and the 3DS challenge-response sequence.
Easy, step-by-step instructions for developers.
| Step | Actor | Action |
|---|---|---|
| 1 | Merchant Server | Create Order – Send a POST request to /orders to create a new order. |
| 2 | Gateway | Responds with orderReference and order in STATE: STARTED. |
| 3 | Merchant Server | Submit Card Details via a PUT to /payments/{paymentRef}/card. |
| 4 | Gateway | Responds with STATE: AWAITING_3DS and returns values like PaReq, ACS_URL, MD. |
| 5 | Merchant Server | POST to ACS_URL (outside Gateway) to initiate 3DS challenge. |
| 6 | ACS | Sends back PaRes and MD after challenge is completed. |
| 7 | Merchant Server | POST 3DS outcome to /card/3ds. |
| 8 | Gateway | Validates 3DS outcome and either authorizes the transaction or returns a failure. |
| 9 | Merchant Server | Receives final state: AUTHORISED, CAPTURED, or FAILURE. |
Direct API Integration Flow — This diagram outlines the step-by-step flow for processing card payments with 3D Secure using the N-Genius Online Direct API, including the key API calls and 3DS challenge-response steps.