Four Types of Memory and Six Design Axes: The Design Space of Agent Memory Systems
CoALA splits agent memory into working, episodic, semantic, and procedural — but the four-cell taxonomy alone doesn't explain why Claude Code uses Markdown files while Mem0 uses vectors. This post adds six independent design axes (read mode, write timing, fidelity, write authority, forgetting, scope) and a file-to-graph spectrum to map the full design space of agent memory systems in 2026.