ENVRI-FAIR is the connection of the ESFRI Cluster of Environmental Research Infrastructures (ENVRI) to the European Open Science Cloud (EOSC). The high-impact ambition of ENVRI-FAIR is to establish the technical preconditions for the successful implementation of a virtual, federated machine-to-machine interface to access environmental data and services provided by the contributing ENVRIs. This interface is called the ENVRI-Hub. Full integration of services across RIs and even subdomains is continuously progressing at ENVRIs with focus on environmental data and scientific research objectives. Each RI is specialized in a specific number of parameters related to its specific competences. For users that require a broader or the full spectrum of environmental parameters, the ENVRI-Hub will offer a platform that reflects the complexity and diversity of the ENVRI landscape, while preserving their specific structures and addressing the requirements they were designed for. The ENVRI-Hub will be a federated system of harmonized subdomain/RI-specific systems of data policies and management, access platforms and virtual research environments. The system will be completely open source, modular and scalable and build on the experience available in the consortium and already operational systems. Figure 1 shows the key features of the ENVRI-Hub. The ENVRI-Hub community metadata and data store is foreseen to be based on semantic web technology, ontologies, and open linked data, allowing integration of the vocabularies and metadata standards developed in the implementation work packages of ENVRI-FAIR. The cross-subdomain development will create large benefits in efficiency and robustness of the ENVRI-hub system. It will enable true interoperability of access to metadata and data objects across the RIs and subdomains and thus facilitate the development of (joint) higher-level services. By following a strict modular design, the developments can be (re-)used in the different RIs. All components should contain couplers to the EOSC services, like AAI, data storage solutions and catalogue of services, to enable the seamless integration of ENVRIs data and services into EOSC.

The authors of this report were supported by the whole ENVRI-FAIR Task Force 6 Team.