Built a reward-function debugger for RL. Looking for feedback from people.
While experimenting with GRPO training, I kept running into a problem that when reward increases, it becomes difficult to tell whether the policy is genuinely improving or simply exploiting the reward function. So I built a small library called rewardspy that wraps an existing reward function and continuously monitors indicators that often precede reward hacking. It currently tracks things like: rolling reward statistics reward variance collapse reward component imbalance response length drift reward slope changes GRPO group collapse, […]