The Driftproof receipt for improve-codebase-architecture on Claude Haiku 5.5, dated 2026-11-08, and what it can say.
improve-codebase-architecture on claude-haiku-5-5
Passing
A case separated upward under the band rule. That is a separation detected under the rule, not proof that the skill moved the score.
Skill token cost: +2137 input and +283 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.831 | ± 0.061 | 3 |
| without the skill | 0.616 | ± 0.155 | 3 |
Lift +0.214, ± 0.166. A spread is the sample standard deviation of the per-case means: a descriptive spread with no coverage probability. The verdict above reads each case's two bands, not these aggregates.
What was verified
receipt_hash verified when this page was built from receipts/canary/2026-11-08/improve-codebase-architecture-claude-haiku-5-5-2026-11-08-16c69348adf1.json; run.transcripts records hashes-only.
Receipt hash: 16c69348adf10f32e7f53fad9df64947b1effeda19f82c24d57e1c2fd2379494
Check this file yourself
validate shows that this file is unchanged since it was sealed. It does not show who made it or who sealed it.
curl -fsSLO https://raw.githubusercontent.com/driftproofhq/driftproof/main/receipts/canary/2026-11-08/improve-codebase-architecture-claude-haiku-5-5-2026-11-08-16c69348adf1.json
npx driftproof@0.28.0 validate improve-codebase-architecture-claude-haiku-5-5-2026-11-08-16c69348adf1.json