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Memory that never forgets becomes memory you can’t trust. Nora exposes several ways to remove information — some automatic, some manual, all reversible where practical.

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Four ways things leave memory

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TTL (time-to-live)

Every memory item can have a TTL. When the clock runs out, the item is dropped. Set at write time:
  • Auto — new items get the space’s default TTL.
  • Explicit — the Agent (or your code) sets a per-item TTL. Common patterns:
    • Session summaries: 24 hours.
    • Temporary preferences: 30 days.
    • Facts with an expiration date: TTL = date.
Items with no TTL persist indefinitely (subject to importance decay, below).

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Importance decay

Every read updates an item’s importance-weighted use score. Items not retrieved for a long time decay. When importance drops below a threshold, the item is quietly retired. Decay rate is configurable per space. Turn off entirely (Retention = permanent) for glossaries and reference notes that should stay regardless of use.

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Manual supersede

Right-click any note → Supersede. Like knowledge supersede, the item is hidden from retrieval but retained for audit. Fully reversible. Common cases:
  • Fact was wrong — supersede and write a corrected version.
  • Preference changed — supersede the old preference, let the Agent write the new one.

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Hard delete

For GDPR erasure, PII takedowns, or legal orders. Permanent. Two flavors:
  • Delete item — one specific item.
  • Delete scope — every item under a scope key. Useful for “delete everything I know about user X”.
Deletion is irreversible. There’s a 7-day soft-delete window (item marked for deletion, hidden immediately, physically removed after grace) so accidental deletes can be undone.

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Auto-forgetting cadence

By default, Nora runs a nightly forgetting pass per space:
  • Drops expired TTL items.
  • Runs decay on importance scores.
  • Hard-deletes items past their soft-delete grace.
Configurable per space. Turn off for spaces where you want tight control (compliance, high-stakes memory).

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Compliance

The User data export and User data deletion endpoints (documented in Compliance) walk every memory space and produce or delete all items matching a scope. Meets GDPR/CCPA erasure requirements. Audit log: every deletion is logged with actor, timestamp, item ID, and reason. Retained separately from the memory itself.

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Reasons the Agent might “forget” without you deleting anything

Not every disappearing memory is deletion:
  • Consolidation merged multiple notes into one (the content is preserved, but under a different item).
  • Scope changed at runtime, and the memory is now invisible from the current scope.
  • Filter changed on the memory attachment, and the item no longer matches.
Check the Trace’s memory ops when investigating “the Agent used to know this — why doesn’t it anymore?”