Persist a durable project fact to the nearest AGENTS.md so future sessions skip rediscovering it. Call this PROACTIVELY the moment you learn something lasting and non-inferable — do not wait to be asked. Triggers: an architecture decision or its rationale; a naming/structure convention; a build/test/deploy command that isn't obvious; a gotcha or footgun you hit; a tooling quirk (e.g. uses Fossil not git, runs behind a proxy); a 'we tried X, it failed, use Y instead' lesson. Also call it when WRAPPING UP a task that revealed any such fact: before you report completion, ask yourself 'did I learn something a future session would have to rediscover?' and if so, save it. Do NOT save: transient state (current bug, a path you're editing now), secrets/credentials, anything trivially re-derivable from the code, or facts the user explicitly said are one-off. Keep each fact one concise sentence. Returns merge instructions which you then carry out with your own Read/Edit tools. Exception: if no memory file exists yet, this creates it directly and no further action is needed.

Remove outdated or wrong facts from the nearest AGENTS.md. Call this PROACTIVELY the moment you notice a stored fact no longer holds — do not wait to be asked. Triggers: you read AGENTS.md and a fact contradicts what you observe in the code; a command/path/convention it describes has been renamed or removed; a decision it records was reversed; a refactor made it obsolete; or you just changed something that invalidates an existing entry. Whenever you act on a fact from memory, sanity-check it against reality first — if it's stale, forget it. Keeping stale memory is worse than none: it misleads future sessions. Describe what to remove in natural language; matching is fuzzy. Returns instructions which you then carry out with your own Read/Edit tools, leaving all other facts intact.