This deliverable reports on the first stage of Service Design and Implementation Work Package (WP9) within the ARTEMIS project. The work carried out during the first period (M1-M9) focused on defining the methodology for service design and specifying the first set of services across the domains of IoT, Simulation, and AR/VR, aligned with the objectives of ARTEMIS and in close collaboration with WP7 (Infrastructure) and WP11 (Pilots). The activities addressed three main objectives: Definition of services to be integrated into the ARTEMIS infrastructure, including IoT, simulation, and AR/VR microservices. Design of a modular and reusable architecture, based on REST APIs and WebSockets, ensuring interoperability, scalability, and flexibility across different cultural heritage scenarios. Alignment with ARTEMIS infrastructure and ontology (WP7), guaranteeing semantic consistency and facilitating integration with pilots (WP11). Key achievements of this reporting period include: For Task 9.1 (IoCT Services), the specification of RESTful microservices for node registration, data management, decision rules, and manual override, as well as the development of the ARTEMIS_IoT_Viewer use case, which demonstrates how these services are operationalized in a RHDT environment. For Task 9.2 (Simulation Services), the definition of services such as illumination, climatic, sensor, and crowd simulation, geometric alignment, and synthetic data generation. These services provide the computational layer of the RHDT. For Task 9.3 (AR/VR Services), the design of microservices for annotation, annotation grouping, geometry optimization, and remote rendering, including the implementation of real-time collaborative functionalities based on a combined REST/WebSocket model. Moreover, additional services are provided for organizing, linking, and navigating information entities, to be interlinked with previous services.These include the Spatial Hypertext Service for collaborative visual structuring of data, the Hypertext Knowledge Base (HTKB) for storing and retrieving context-specific knowledge, and supporting services such as the Navigational Hypertext Service and the Hierarchy Service. These services enable dynamic knowledge representation and integration with other ARTEMIS components and pilots. Overall, WP9 has successfully delivered the foundational specifications and architectures needed to develop interoperable and reusable microservices across IoT, Simulation, and AR/VR. These results provide the basis for the development and the integration of services into the ARTEMIS infrastructure and pilots, supporting the project’s overarching goal of developing a modular, scalable, and reactive digital twin platform for cultural heritage.