The documentation is included in the package.
Open the SDK_help html file in the root directory after you unzip the package.
More detailed documentation of APIs is available from within the ZExplore utility found in the 'zedi' directory.
You may want to take a look at the SDK API programming webinar I did for FastLane:
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, IT Learning Solutions http://sg.itls.asia/netapp
(P.S. I appreciate 'kudos' on any helpful posts.)