Recursive Self-Improvement Stability under Endogenous Yardstick Drift

This paper develops a first-principles interface theory for recursive self-improvement under endogenous yardstick drift: the setting in which a system does not merely improve policies or code, but also changes its own evaluator, benchmark, parser, routing logic, memory substrate, and verification process. The central problem is not whether self-modification can produce short-term gains, but whether a self-editing system can still distinguish claimed improvement from stable improvement when the ruler itself moves. The framework is organized around replayable observable interfaces rather than privileged semantic oversight. It separates four layers that are often conflated in self-improving systems: base…