cost-diff
Installation
SKILL.md
PR-level cost regression detection. Where cost-counterfactual compares to HYPOTHETICAL baselines (always-haiku/sonnet/opus) and cost-burn compares latest bucket to PRIOR MEAN, cost-diff compares two SPECIFIC known-good snapshots.
| Question | Skill |
|---|---|
| "What would we have spent at always-X?" | cost-counterfactual |
| "Is daily burn accelerating vs prior mean?" | cost-burn |
| "Did THIS PR add spend vs main?" | cost-diff ← this |
Algorithm
Implementation: scripts/diff.mjs. Consumes the
stable JSON contract from cost summary --format json.