Parts of Agia's developer documentation is available online. The complete Developer's Guide is supplied with Agia and it contains API (Application Programming Interface) documentation for Agia framework.
Helin, Joni. A Generative Approach to the Presentation and Manipulation of Hierarchical Data Generative Programming and Component Engineering (GPCE'02), Young Researchers Workshop. Pittsburgh, PA, 5 Oct. 2002. GCSE/SAIG (2002)
Something to decorate your cubicle with: Agia poster [pdf]