Hi @h-scheidl, many thanks for your feedback and our sincere apologies that you have not had the optimal experience that we endeavour to provide to all our customers.
We are aware that there is still work to be done in getting the online Core SDK documentation improved for new users, so we greatly appreciate your comments on this matter. With reference to the Nuget Packages, indeed Tobii has a number of offerings available including the Stream Engine and Tobii Pro SDK so any confusion is understandable and we will seek to clarify the Core SDK documentation to reflect this. For your purpose of developing against the Core SDK, the appropriate library is “Tobii.Interaction” which you have no doubt already discovered.
In the meantime, it may interest you to check out a few sample applications we have developed which illustrate how to implement key eye tracking features within the Core SDK which you can download @ https://github.com/Tobii/CoreSDK
And of course, should you have any further feedback or questions, please do not hesitate to get in touch again and we will be more than happy to help out.