VendEnv

VendSim VB2 is an OpenEnv 0.2.1 environment that drops an LLM agent into a 365-day vending machine business simulation. The agent starts with $500 and must maximize its bank balance by setting prices across 5 products, negotiating with adversarial suppliers, managing inventory through a delegated sub-agent, and surviving daily fees, weather-driven demand shifts, and seasonal fluctuations. The environment features an MCP tool-calling interface with 16 tools spanning pricing, supplier negotiation, inventory management, and a scratchpad memory system. Rewards scale uncapped with agent performance — a skilled agent can grow net worth well beyond the starting capital, while poor decisions lead to bankruptcy. We train with GRPO using Unsloth on a Qwen2.5-1.5B model, demonstrating measurable improvements in pricing decisions and revenue generation over the training steps.