  Semantic representation is a key enabler for several application domains, and
the multi-agent systems realm makes no exception. Among the methods for
semantically representing agents, one has been essentially achieved by taking a
behaviouristic vision, through which one can describe how they operate and
engage with their peers. The approach essentially aims at defining the
operational capabilities of agents through the mental states related with the
achievement of tasks. The OASIS ontology -- An Ontology for Agent, Systems, and
Integration of Services, presented in 2019 -- pursues the behaviouristic
approach to deliver a semantic representation system and a communication
protocol for agents and their commitments. This paper reports on the main
modeling choices concerning the representation of agents in OASIS 2, the latest
major upgrade of OASIS, and the achievement reached by the ontology since it
was first introduced, in particular in the context of ontologies for
blockchains.
