Datakit API allows you to read data coming from many software in the same way:

You have to Enable the readers you want to use and then Start the Api.
When API is started you can Use OpenDocument() method to read a file.
This method recognizes file format and calls the corresponding reader to give you an assembly tree.
From assembly tree, you choose the component you want to read and call ReadComponent method to get Construction tree.
From this second tree, you call Get.. method on node following his type to make the reader access to full data information.
You have to close opened component with EndComponent() and opened document with EndDocument() method to free data used by the reader.
In the end, you need to stop the API.

All classes except Dtk_API and Dtk_readers are handled via Smart Pointers.
You have to use the Create method to handle them. They are deleted automatically when they are not used any more.