The transcript is a log, not an index: retrieval for long-running agents
Eviction and summarization keep a long-running agent’s window small, but the summaries themselves still accumulate in the linear transcript — and on a run long enough, that accumulation becomes the new quadratic. Past a few hundred steps, the fix isn’t a better compaction policy inside the window. It’s moving history out of the window entirely and querying it like a database instead of replaying it like a log.