#3325 · EPIC D · playground · 2026-08-11

Adopt the native mechanism, delete the imitation.

CC 2.1.219+ ships autoCompactWindow: a user-settings integer (100k..1M, schema verified in the 2.1.227 binary) that arms CC's native precomputed compaction. ork's four-hook compaction layer approximated the same idea with home-grown token accounting, and #3321's verification showed how that went: the imitation's key branches never fired once. This PR documents the native offer and deletes the parts proven dead.

Deleted, with the proof each carried

whatwhy it could not fire
prompt/context-exhaustion-warner (whole hook)its bridge file has had zero writers since 2026-03-29 (#1194 deleted the writer, no replacement); every run since was a silent no-op. Confirmed three independent ways.
cache-heat machinery (evaluateCacheHeat, recordCacheTokens, warm-cache messages in 2 hooks)CC's SubagentStop payload sends neither cache token field (verified in the binary), so the sole writer's zero-check always returned early; 0 of 93 real state files ever non-zero.
3 closed-loop testshand-built fixtures with cacheReadTokens values no writer could produce, asserting phrasing only impossible input could trigger — the same disease as the TeammateIdle duration tests.
net: -910 lines (27 files, +555 / -1,465)

Adopted

The sixth offer in doctor's settings-posture

autoCompactWindow joins ENABLE_TOOL_SEARCH and friends as an info-level OFFER: real, useful, optional. ork cannot ship it — a plugin settings.json is not a settings scope CC reads (binary-proven at 2.1.226) — so the doctor recommends and never sets.

Deliberately NOT deleted

The imminent-zone gate stays, and #3321 stays open

The gate has never fired (0 of 2,246 recorded invocations since it landed), but deleting it would ENABLE a compaction blocker that has never run in production — a behavior change to be measured on its own, not a cleanup to ride along. Same reasoning for the estimatedTokens unit mismatch (a subset-counter checked against a whole-window threshold): recalibration is a design decision, recorded on the issue.

Verification

typecheck            exit 0
hook TS suite        310 files · 7588 passed · 2 skipped
hooks + plugin build exit 0
counts               validate-counts.sh exit 0 (warner was a dispatcher stage,
                     no hooks.json entry, so no restamp due)

Theme of the week, fifth instance. #3411's shell_cwd, #3410's worktree layouts, the payload keys, the closed-loop tests, and now a warner reading a file whose writer was deleted five months ago: ork keeps holding beliefs about its environment that nothing checks against the environment. The native autoCompactWindow needs no belief — CC enforces its own contract.