The future of AI is “stateful agents” - agents that can learn from experience.
Large language models possess vast knowledge, but they're trapped in an eternal present moment. While they can draw from the collected wisdom of the internet, they can't form new memories or learn from experience: beyond their weights, they are completely stateless. Every interaction starts anew, bound by the static knowledge captured in their weights.
As a result, most “agents” are more akin to LLM-based workflows, rather than agents in the traditional sense.
The next major advancement in AI won't come from larger models or more training data, but from LLM-driven agents that can actually learn from experience. At Letta, we are calling these systems “stateful agents”: AI systems that maintain persistent memory and actually learn during deployment, not just during training.
Most LLM APIs and agentic frameworks that are built around the assumption of statelessness. State is assumed to be limited to the duration of ephemeral sessions and threads, baking in the assumption that agents are and always be stateless.
A stateful agent has an inherent concept of experience. Its state represents the accumulation of all past interactions, processed into meaningful memories that persist and evolve over time. This goes far beyond just having access to a message history or a knowledge base via RAG.
Key characteristics include:
- A persistent identity providing continuity across interactions
- Active formation and updating of memories based on experiences
- Learning via accumulating state that influences future behavior
The next generation of AI applications won't just access static knowledge - they'll learn continuously, form meaningful memories, and develop deeper understanding through experience. This represents a fundamental shift from treating LLMs as a component of a stateless workflow, to building agentic systems that truly learn from experience.
The term "agent" has strong roots in reinforcement learning (RL) but recently has started to lose all meaning - "stateful agents" adds an important qualifier to the term to clearly distinguish it from an "LLM-driven workflow". Next time someone tells you about the agent they're building, try asking them if it's a stateful agent - if not, why?
Full blog post on stateful agents in comments. ??