concordia

Concordia is Google DeepMind's open-source library for generative social simulation. It builds generative agent-based models in which entities powered by a language model interact in grounded physical, social or digital environments. The interaction pattern comes from tabletop role-playing games: a special Game Master entity simulates the environment, player entities describe their intended actions in natural language, and the Game Master decides what actually happens, for example by checking physical plausibility.

It is used for social science research, AI safety and ethics studies, cognitive science, economics, synthetic data generation for personalisation, and evaluating real services through simulated usage. Simulations are built from entities made of components (instructions, memory, action selection and so on); prefabs provide ready-made entity templates you can customise, and an engine runs the loop that assigns player and Game Master roles. A GUI and command-line interface let you inspect components, edit a simulation and watch its behaviour, and the design is documented in a tech report and a design-pattern paper.