This project addresses the coproduction of climate-impacts knowledge, in a hands-on collaboration between scientists and users such as climate-adaptation-policy experts and other stakeholders. The project team boasts world-class experts in science-policy dialogue, cross-sectoral impacts research and research coordination, and scientific excellence in impacts modelling. The end product is an open climate-impacts service portal, ISIpedia, offering tailored access to state-of-the-art climate-impacts assessments and data, based on the cross-sectoral, multi-model simulations conducted within the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP, www.isimip.org). ISIpedia’s development will integrate the full chain of climate-impact-service co-development, from research design and implementation, to delivery, with tasks fulfilled by the ISIMIP team, a Stakeholder Engagement Team (SET), and the ISIpedia Assessment and Editorial Team (AET). ISIpedia users may include climate adaptation planners e.g. involved in National Adaptation Plans (NAPs) and implementation practitioners, regional knowledge hubs, trans- and interdisciplinary scientists including climate economists, and regional climate experts from the private sector such as (re-)insurance companies. Four key tasks will be undertaken: 1) stakeholder-supported selection of focus topics and development of the scenario design for the next ISIMIP simulation round; 2) co-development of societally- and user-relevant impacts indicators based on the (bio-)physical projections generated within ISIMIP, such as “number of people affected”, “economic damages” or indicators related to the Sustainability Development Goals; 3) provision of input data and coordination of cross-sectoral impact-modelling activities within ISIMIP, and 4) establishment of a new online platform ISIpedia to provide informed access to simulation data, regional, cross-sectoral impact assessments based on ISIMIP data, and co-developed indicators.