Abstract OpenDISCO is an open-source framework for decentralized simulation and security assessment of distributed power grid control. By incorporating security assessment directly into the control algorithms’ implementation process, the proposed framework aims to enable the rapid development of new control strategies. It provides a modular structure, enabling engineers and researchers to define own stress conditions and to simulate predefined cyber-attacks, thereby enabling continuous evaluation during the integration into existing power systems. A demo setup is presented, comprising a micro grid simulation and implementing a Controller-Hardware-in-the-Loop configuration.