The DIAMOND multi-layered stakeholder engagement strategy will accompany and enrich the research process by enabling the exploration of the multiplicity of perspectives on how models can address concerns from the target groups, attending carefully to differences, complexities, and range of variation in the data. It provides a description of the heuristic cross-disciplinary integration methodology adopted in the project; illustrates the co-design process involving researchers (e.g., modellers, SSH researchers), policymakers, business, social and environmental stakeholders, and citizens; and gives details on the stakeholder engagement plan. In this update, we highlight how the integrated approach facilitates seamless interaction with other WPs, optimising co-creation and application of models, scenario building, and policy roadmap development. The strategy also takes stock of the work done in Phase 1 of the co-design process. It provides an update on the status of the stakeholder database, which—by the time of the submission of this document—incorporates more than 50 stakeholders pledging to actively participate in all DIAMOND stakeholder- related activities. Stakeholders from an initial mapping of 300 project partner contacts are continuously approached to gather their interest in participating in project activities like foresight workshops, meetings, and surveys, and ensure representativeness and diversity. These are expected to play a key role in the co-design process, and those initially allowing us to contact them will be invited to strategic foresight workshops alongside other experts, and other project activities. The report also provides examples of the macro-questions to trigger each stage of the dialogue loop between researchers and practitioners aiming to co-create and assess climate change neutralisation actions, and the database structure for stakeholder engagement.