Continuum Memory Architectures for Long-Horizon LLM Agents
Joe Logan
TL;DR
The paper identifies a gap in long‑horizon LLM agents: memory should evolve over time rather than remain as static retrieval data. It defines Continuum Memory Architectures (CMA) as a persistent, mutable memory substrate with selective retention, associative routing, temporal continuity, and consolidation, operating via an ingest–activation–retrieval–consolidation lifecycle. Through four behavioral probes, CMA demonstrates clear advantages over a strong RAG baseline in knowledge updates, temporal association, associative recall, and disambiguation, while highlighting latency, drift, and interpretability as key challenges. The work positions CMA as a foundational architectural primitive for reliable, persistent AI agents and provides a concrete instantiation and evaluation framework to catalyze further research and safe deployments.
Abstract
Retrieval-augmented generation (RAG) has become the default strategy for providing large language model (LLM) agents with contextual knowledge. Yet RAG treats memory as a stateless lookup table: information persists indefinitely, retrieval is read-only, and temporal continuity is absent. We define the \textit{Continuum Memory Architecture} (CMA), a class of systems that maintain and update internal state across interactions through persistent storage, selective retention, associative routing, temporal chaining, and consolidation into higher-order abstractions. Rather than disclosing implementation specifics, we specify the architectural requirements CMA imposes and show consistent behavioral advantages on tasks that expose RAG's structural inability to accumulate, mutate, or disambiguate memory. The empirical probes (knowledge updates, temporal association, associative recall, contextual disambiguation) demonstrate that CMA is a necessary architectural primitive for long-horizon agents while highlighting open challenges around latency, drift, and interpretability.
