Revit 2015 SDK Direct Download Link

Updated version:

• Revit 2015 SDK (Update May 14, 2014) (msi – 242795Kb)

how to install and compile the SDK samples.

Revit 2015 SDK (Update April 11, 2014) (msi – 242779Kb)

From:
Autodesk – Autodesk Developer Network – Autodesk � Revit, Autodesk� Revit� Architecture, Autodesk� Revit� Structure and Autodesk� Revit� MEP