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: +2132 input and +256 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.819 | ± 0.076 | 3 |
| without the skill | 0.604 | ± 0.128 | 3 |
Lift +0.215, ± 0.148. 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/which-section/improve-codebase-architecture/compare-A-f95f2a97f82743a4039ece0c0cc3bbc3aff33368e6c459dc15d6b7617d59a5ff.json; run.transcripts records hashes-only.
Receipt hash: f95f2a97f82743a4039ece0c0cc3bbc3aff33368e6c459dc15d6b7617d59a5ff
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/which-section/improve-codebase-architecture/compare-A-f95f2a97f82743a4039ece0c0cc3bbc3aff33368e6c459dc15d6b7617d59a5ff.json
npx driftproof@0.28.0 validate compare-A-f95f2a97f82743a4039ece0c0cc3bbc3aff33368e6c459dc15d6b7617d59a5ff.json