Originally published on m-i-n-d.ai. I write and maintain MIND, an MCP memory server — full disclosure up front, since this piece also covers memory options that aren't ours.
What Is Agent Memory?
The four types, how the major frameworks differ, and how to add real memory to an agent you're building.
By Anthony Conti · Astra AI, LLC · Last updated September 7, 2026
Agent memory is the mechanism that lets an AI agent retain information — facts, preferences, past actions, and outcomes — across turns, sessions, and tools, instead of starting from zero every time its context window resets. An agent without memory can reason brilliantly inside one conversation and remembers nothing about the person or task the moment that conversation ends. Memory is the layer that fixes that, and it is a genuinely separate concern from the model, the framework, and the context window.
