The coupler library OASIS3-MCT has been successfully implemented into the MESSy environment by Dr. Astrid Kerkweg from the University of Bonn, an associated University partner of the HGF-ESM project. Within the HGF-ESM project, OASIS3-MCT will be used to couple the FESOM2 ocean compartment (Finite-volumE Sea ice-Ocean Model) with the chemistry-climate model EMAC within the MESSy framework. FESOM2 is developed by colleagues at the Alfred-Wegener Institut (AWI), who also support this newly coupled system. OASIS3-MCT can also be applied to couple other compartments. During this 3-day workshop, the new features of the MESSy code were presented and discussed for the intended application. The coupling of the chemistry-climate model EMAC with the FESOM2 ocean model provides a further step towards a chemistry enabled Earth System Model (ESM) in the MESSy environment.