During the graduation project for the HBO-ICT education, the student has worked on a projectcommissioned by Thales Group. Thales uses Apache Avro to specify the API they use. Basedon this specification, empty methods are generated and filled out by Thales developers.However, they want to specify more than just the API: they want to specify the behaviouras well. This behaviour specification would be used to validate whether the program behavesas is intended. Interface Description Languages (IDLs) were researched to find a candidatewith such functionality, and the result was Component Modelling and Analysis (ComMA),proprietary IDL developed by TNO and Philips. However, ComMA doesn’t support all featuresApache Avro does.This project involved preparing the transition from an IDL Thales currently uses, ApacheAvro, to the ComMA IDL. For every feature of Thales’ current IDL Apache Avro that isn’t sup-ported by ComMA, a feature proposal has been created for ComMA. These proposals have beenapproved by Thales and a proof-of-concept implementation has been created for all proposals.