The following sequence diagram is the most simplified version of my application's sequence diagram. The API calls below are all HTTP requests. I want to send a secure code grant to App_B when App_A_Client calls App_B_endpoint/GetData(). App_B would sends this code to App_A_Backend as part of App_A_ebdpoint/Enhance_Data() call. I want to compare this code with what I sent as part of App_B_endpoint/GetData().
Here is my question - How can App_A_ebdpoint\Enhance_Data() figure what was sent as part of App_B_endpoint/GetData()? These calls are independent of each other. I was thinking of using session storage but there are redirects so, I will loose this code.