This artifact report is a companion to the ESOP’25 paper An abstract, certified account of operational game semantics [3]. The paper describes the construction of a sound model for an abstract notion of language. The model is built using a semantic technique named Operational Game Semantics (OGS). All our results are mechanised in the Coq proof assistant: this mechanisation (The proof artifact is archived at https://doi.org/10.5281/zenodo.14697618 .) constitutes the artifact we discuss in the present document. More specifically, our mechanisation covers our main result, the soundness of the abstract OGS model w.r.t. substitution equivalence (Theorem 8), as well as four example calculi: two variants of call-by-value \(\lambda \) -calculus and two variants of \(\mu \tilde{\mu }\) -calculus [4, 5]. The only axiom used is the Axiom K [17] for equality proof irrelevance (To ease dependent pattern matching due to the intrinsically scoped representation.). The README explains the installation process and the structure of the code. An online rendering ( https://lapin0t.github.io/ogs/esop25/Readme.html .) is available thanks to Alectryon [12]. Furthermore, the main paper provides systematic hyperlinks from statements to their Coq counterparts. We encourage the interested reader to use these tools to navigate the code. In this document, we focus first on users: how to read and instantiate our main result. We then detail salient technical aspects of our mechanisation.