Armstat

clawback per-arm turn-log stats

Run from the project root against one or more turn-log NDJSON files:

node benchmark/bin/arm_stat.js runs/<run>/turns.A0.ndjson
node benchmark/bin/arm_stat.js runs/<run>/turns.*.ndjson   # whole suite so far

Read-only — it only reads files already on disk, never the running proxy, so it is safe to run while a benchmark arm is still driving.

What it reports, per file

• turns — billable client turns (+ keep-alive treatment-ping records, counted separately and excluded from the billable tally), and any partial trailing line skipped on a live file.
• httpStatus — status tally with a ✓ when all are 200, or a ⚠️ flag the moment any non-200 appears (early rate-limit / error detection mid-run).
• ttlMode — 5m/1h tally (passthrough arms stay 5m).
• cache_read / cache_create — token sums, plus the per-turn first→last cache_read (warm-cache build-up), and the ephemeral 5m-vs-1h split. The split is a direct knob check: the 1h-TTL arms (A2/A3/A5) should show ephemeral_1h > 0; A0/A1/A4 should not.
• hit rate — token-weighted cache_read / (cache_read + cache_create + input). A quick diagnostic only; the defensible headline is billable input reclaimed per turn with a CI, which the bench analyzer computes.
• thinkingBudget — distinct budgets seen and how many turns carried one (Haiku emits ~31999 regardless of --effort).

When to use

• At each arm boundary of an in-flight suite, to confirm the just-finished arm produced turns, hit no rate-limit (all 200), warmed its cache, and applied the knob it was supposed to (5m vs 1h).
• NOT a substitute for bench: no CIs, no gap-bucket stratification, no pricing. Run bench for the committed study report.

Sensitivity

Turn-logs carry per-turn token usage (not prompt content). Treat the run directory as sensitive; this tool prints only counts and token sums.