Our goal is to create a definition of Grace that is readable as a reference specification of the syntax and dynamic semantics of the language, and that is also the source of the implementation of an IDE and interpreter. In this talk we present a first version of a definition in the Spoofax language workbench of the Grace language. The definition consists of a syntax definition in SDF3 from which we generate a syntax aware editor, desugaring transformations in Stratego that reduce source ASTs to a core language, and a big step operational semantics in DynSem. The definition is available in github.