This compendium is a strategic effort to define a structured set of data standards, promoting interoperability within the realms of Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA). We aim to craft a cohesive framework that ensures the seamless interchange of data across a diverse array of models, databases and both analytical and visualization tools, with the ultimate goal to enhancing the efficacy of DRR and CCA initiatives. Additionally, the assessment focuses on standards that facilitate the closure of prevalent gaps in spatio-temporal scales and enable comprehensive multi-hazard and multi-risk assessments. Proposed methodology grounds in the principles and recommendations of the European Interoperability Framework (EIF) and aligns with the strategic directives set forth in the EU eGovernment Action Plan 2016–2020. It involves a thorough analysis of interoperable standards endorsed by renowned international entities, such as the Open Geospatial Consortium (OGC), and aligns with established EU initiatives, notably INSPIRE. In the evaluative process, particular attention has been paid to replicability of successful existing practices exemplified by initiatives like The United Nations Environment Programme (UNEP) Preview, Copernicus, and others. A rigorous Multi-Criteria Assessment, informed by the FAIR principles is employed to rank these standards. The intent is to distill a compendium of interoperability best practices that are not only reusable but are also optimally suited for DRR and CCA applications. Moreover, this compendium explores the crucial mechanisms of collaboration and stakeholder engagement, recognizing the importance of multi-stakeholder analysis in enhancing interoperability and ensuring that data tools are shaped by, and responsive to, the needs of a broad spectrum of actors in the DRR and CCA domains. The outcomes of this compendium are poised to inform the architectural design and technical specifications of the Data Fabric component also developed in DIRECTED. Furthermore, the analysis provides a foundational baseline for determining the Technology Readiness Levels (TRLs) of various interoperable tools, setting the stage for their subsequent development and integration. Critical to the success of interoperability in DRR and CCA is the establishment of standardized taxonomies and ontologies, as explored for example by the Climate Connectivity Hub1, developed by SEI. Such standardization lays the foundation for clear data interaction and semantic interoperability, which are instrumental in informed decision-making processes. The overarching ambition of this compendium is to serve as a cornerstone for building a more resilient, responsive, and integrated DRR and CCA data ecosystem, empowering stakeholders to make informed decisions in the face of growing climate-related challenges.