Comment by wooders

I think the "memory blocks" are essentially what you are describing - to have an infinite session (which systems like Letta is designed for) you have to have a mechanism for organizing the important information and persisting it for future interactions. This organization can be done via tool calls (which was what MemGPT did) or done by other agents in the background. While the message buffer is continues to grow / old messages get evicted, the memory blocks are fixed size and always in context.