Read is 0 in all 24 runs of both arms across client-go and excalidraw, no
isError, codegraph is the last tool in every run, and both "Read a file we
returned" / "did not return" buckets are empty — with back-references
demonstrably reaching the agent in 8 of the 9 multi-call runs.
Residual occupancy is flat, and the measurement shows it could not have been
anything else: CG-18 was accepted on the rule that reclaimed bytes get spent on
unseen files rather than banked, so the byte count cannot fall. What moves is
the duplicate fraction of that residual — 87% less across the agent runs, 86%
and 94% on two matched deterministic replays.
Also recorded: dedup.savedChars is a pre-clip figure (11,450 reported against
1,042 chars actually re-served), so tuning off it inflates the win ~7x.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Extends the session-state design doc with the layer built on it: what gates a
withheld span (session, content fingerprint, two size floors, kill switch),
why the fingerprint and not #1474's drift flag, the two channels the
reclaimed bytes leave by, and why "no duplicate ranges across calls" holds
for every call that had something new to say rather than universally.
Colby McHenryandClaude Opus 5