X-FLEX aims at designing, developing and demonstrating a set of tools to integrate the emerging decentralized ecosystem of RES and flexibility systems into the existing European energy system, in an efficient and cost-effective manner, to create more stable, secure and sustainable smart grid, with special attention to extreme weather conditions. The project addresses all the actors of the smart grid value chain, from DSO to final consumers, including microgrid operators and utilities, considering flexibility in both on the generation and on the demand side, on an individual or aggregated level.