MEMORY/ is the persistent state layer of PAI — the place where every session, learning, observation, and artifact accumulates over time. Where KNOWLEDGE/ is curated and USER/ is identity, MEMORY/ is the lived record of what the system has actually done. It is segmented into typed subdirectories (WORK, LEARNING, OBSERVABILITY, RESEARCH, and so on) so each kind of artifact has a predictable home.
In a fresh PAI install this tree is empty by design. No personal data, no prior sessions, no historical bookmarks ship with the system. Each subdirectory contains only a README.md describing what belongs there. Content gets created automatically as you use PAI normally — running the Algorithm spawns ISAs in WORK/, hooks emit events to OBSERVABILITY/, the satisfaction-capture and learning hooks write to LEARNING/, and so on.
Treat MEMORY/ as append-mostly. It is the substrate from which KNOWLEDGE/ is harvested and the source of compounding context across sessions. If you are ever unsure where an artifact belongs, read the subdirectory READMEs — the taxonomy is intentional.