The Driftproof receipt for git-workflow-and-versioning on Claude Opus 5.5, from Report 011, dated 2026-09-23, and what it can say.
git-workflow-and-versioning on claude-opus-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: +5004 input and -49 output tokens per call against no skill (measured, grading excluded).
The two arms
| arm | mean | spread across cases | cases |
|---|---|---|---|
| with the skill | 0.838 | no spread recorded | 1 |
| without the skill | 0.300 | no spread recorded | 1 |
Lift +0.538, no ± (1 case). 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/report-011/git-workflow-and-versioning-claude-opus-5-5-2026-09-23.json; run.transcripts records retained-local.
Receipt hash: ca69c3436d0dbfa5db3258fd227f7d84eca8f3737a41ac09e17c35448dd0bf4b
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/report-011/git-workflow-and-versioning-claude-opus-5-5-2026-09-23.json
npx driftproof@0.28.0 validate git-workflow-and-versioning-claude-opus-5-5-2026-09-23.json