Concordia: a library for generative social simulation

https://github.com/google-deepmind/concordia

Apache-2.0. Entities (player agents and Game Masters), components, and an engine loop. LanguageModel interface defines sample_text and sample_choice; sample_choice scores a list of candidate responses and returns the chosen index, raising InvalidResponseError after several failed attempts. Requires a text embedder for associative memory.

Grammar-constrained decoding for valid game actions, LLM game master and narrative director