With its “Clean Energy for all Europeans” package (CEP), the European Commission formally recognised and instrumentally brought forward community energy projects, including definitions for “Renewable Energy Communities” (RECs) and for “Citizen Energy Communities” (CECs). The new concepts introduced in the CEP set the course for a more active role of EU citizens in the energy markets. To fully concretize the benefits envisioned by the CEP, a myriad of barriers needs to be overcome and progress needs to be done to clarify and streamline the concepts of REC and CEC, enabling its uptake by all interested citizens. Motivated by that challenge, COMMUNITAS will promote energy citizenship, enabling citizens to take control of their own path towards sustainability by becoming an active element of the energy markets. The project will deliver a Knowledge Base that will provide users with technical, administrative, and legal information on ECs, streamlining the creation and expansion of this concept. COMMUNITAS will also deliver an innovative set of tools - capitalizing on technologies such as IoT, Blockchain and Cloud Computing - to unlock citizens’ active participation in energy markets and communities (all integrated into an open, digital “one-stop-shop” COMMUNITAS Core Platform (CCP)), allowing EC members to have an aggregated position in the energy markets or explore ancillary services using different energy assets or load profiles of the community. As a project that aims to position citizens in the centre of energy markets, COMMUNITAS has citizens at the centre of its own approach: citizens will be involved in Social and Policy Labs throughout the whole project, in order to frequently factor in their feedback, wishes, needs into the core developments of the project.