ADR-0007 — Conversation memory as a FIFO queue of summaries

• Status: Accepted
• Issue: #77

Context

Readers saw only the last historyLimit turns verbatim: long conversations forgot their start, and a larger limit made every turn more expensive. A rolling summary that re-summarises itself blurs early details over time.

Decision

• Every every turns, right after the answer, a model compacts them into one self-contained summary (full names, no outside pronouns). Input: its own turns + the raw turns of the previous window as read-only context. Summaries never read summaries.
• Summaries form a FIFO queue: readers see the latest keep (each reader has its own limit) plus the raw turns since the last compaction; older rows stay in the database.
• A compaction failure never fails the turn; its cost is the FinOps category compaction.

Consequences

• ~every × keep turns of memory at the price of ~keep notes.
• The turn that compacts returns a few seconds later.
• References deeper than one window back are not resolved inside a summary.