The language allows it to be easily done. The model definitions can be simply transformed into code that directly handles those individual model artifacts.

This is a super common paradigm in Lisp, especially when it comes to class/structure/data definitions, where support functions of any type can be generated straight from the defs. There is no "automatic" language feature there, because no definition of "automatic" covers all useful cases. It's simply easy to do because of the homoiconic nature of Lisp (code = data = code, with easy manipulation to transform between them), and no real distinction between compile time and run time.