The purpose of this article is to help licensed customers to implement the display of the flicker code challenge types in their applications.

Some banks offer their users a second-factor authentication with the optic chipTAN procedure.

If you are not using the finAPI Web Form in your application, you will have to implement displaying the flicker-code to your users to perform the second-factor authentication. This is applicable to all flows where user authentication is required (e.g. import of the bank connection or payment initiation). The API response will contain the value FLICKER_CODE in the procedureChallengeType.

To help you with creating a flickering animation within your application that you can show to your users, we have implemented a little JavaScript template. As input, it takes the BASE-64 String that you receive from finAPI in the opticalData attribute, as well as the bank’s “Bankleitzahl/BLZ”.

You can download the template here: