
  AI agents don't just forget.
  They remember the wrong thing.

  You corrected it in March. In August it is still saying the old value,
  because the store kept both and marked neither one current.

──────────────────────────────────────────────────────────────
  Alice tells us where she lives. Three times, over five months.
──────────────────────────────────────────────────────────────

  2026-01-10   mem.remember("Alice", "lives_in", "Berlin")
  2026-03-15   mem.remember("Alice", "lives_in", "London")
  2026-06-02   mem.remember("Alice", "lives_in", "New York")

  No model was called. `lives_in` is declared single-valued, so the second
  value closed the first one's interval by lookup, not by similarity.

──────────────────────────────────────────────────────────────
  Where does Alice live now?
──────────────────────────────────────────────────────────────

  >>> [c.object for c in mem.get_all()]
  ['New York']

──────────────────────────────────────────────────────────────
  Where did she live on 20 March? And on 20 January?
──────────────────────────────────────────────────────────────

  >>> [c.object for c in mem.get_all(as_of=datetime(2026, 3, 20, tzinfo=UTC))]
  ['London']
  >>> [c.object for c in mem.get_all(as_of=datetime(2026, 1, 20, tzinfo=UTC))]
  ['Berlin']

  Berlin was not overwritten. It was given an end date.

──────────────────────────────────────────────────────────────
  The whole record, which is what makes those answers lookups.
──────────────────────────────────────────────────────────────

  >>> mem.history("Alice", "lives_in")
  Berlin    2026-01-10 -> 2026-03-15  [ended]
  London    2026-03-15 -> 2026-06-02  [ended]
  New York  2026-06-02 -> now         [live]

  "ended" means the world changed. A value that was never true would read
  "retired" instead, and nothing is deleted either way.

  >>> mem.why(claim_id)
  it replaced:  London (ended)
  written by:   api (user)

──────────────────────────────────────────────────────────────

  Memvara — bitemporal memory for AI agents.

  Know what was true. Know when it was true. Know why you believe it.

  github.com/memvara/memvara          pip install memvara
  memvara.dev

──────────────────────────────────────────────────────────────

