Memento 2: Learning by Stateful Reflective Memory

Abstract

We study continual learning in large language model (LLM) based agents that integrate episodic memory with reinforcement learning. We focus on reflection, the ability of an agent to revisit past experience and adjust how it selects future actions, as the central mechanism for continual adaptation without fine tuning model weights. To formalise this, we introduce the Stateful Reflective Decision Process (SRDP), in which an agent maintains and updates episodic memory and alternates between writing new experiences to memory and reading relevant cases to guide decisions. This framework casts reflective memory dynamics as part of the decision process itself and makes them amenable to control and learning analysis. Building on this formulation, we develop a Read-Write Reflective Learning algorithm that incorporates memory retrieval into a soft policy iteration procedure and prove that it converges. We further show that as memory grows and more densely covers the task environment, the resulting policy approaches optimality. Our framework unifies memory based reasoning with reinforcement learning and provides a formal foundation for LLM agents capable of continual, experience driven learning.