MOSAIC: A Unified Platform for Cross-Paradigm Comparison and Evaluation of Homogeneous and Heterogeneous Multi-Agent RL, LLM, VLM, and Human Decision-Makers

MOSAIC is a new open-source platform that enables cross-paradigm comparison and evaluation of different AI agents including reinforcement learning, large language models, vision-language models, and human decision-makers within the same environment. The platform introduces three key technical contributions: an IPC-based worker protocol, operator abstraction for unified interfaces, and a deterministic evaluation framework for reproducible research.