cadexchanger.com -> reading selected items 3D

hi,
I looking for c# programmer who has experiences in programming 3D for project https://cadexchanger.com/.
It is not easy and is required doing such project in past.

I am going to use demo project for this: selectionhandling_wpf

After selecting edges I want to get a list of objects in Json.
Line like start and end point,
circle like radial and centra point,
arch central point and its angle.

Thank you