EUnixGMS is a high-performance grid and market co-simulation tool designed to model the interaction between local electricity markets and distribution grid constraints. It enables researchers, DSOs, and energy innovators to simulate how prosumers, consumers, and distributed energy resources interact within a smart grid. The platform integrates real-time market operations with power flow analysis, supports Redis-based communication between agents, and offers flexibility for testing different market designs, optimization strategies, and grid management scenarios.