Definition
Plain language
A save operation that updates an existing entry if it's already there, or creates a new one if it isn't.
As stated in the literature
A combined update-or-insert operation keyed by an identifier; in agent memory it overwrites the single record for a given key (e.g., a map coordinate) rather than appending duplicate entries, dramatically shrinking a growing notes file.
Why it matters: It keeps stored records from ballooning with duplicates by updating in place, which matters for keeping an agent's memory compact and usable.
For example, when an agent notes what it found at a map location, an upsert overwrites the old note for that spot instead of piling up a new entry every visit.
Heard on the show
“The reviewer reads the trace, diagnoses exactly that, and introduces a new operation — an upsert on the map, keyed by coordinate.”Episode 192 — A 32B Open Model Matched Frontier Systems By Learning to Take Notes