verify-behavior

# Verify Behavior Given a behavioral claim about code, or a change that was just applied, decide **the cheapest way to get executed proof**, run it in isolation, and report the raw result as a receipt. This skill is the execution engine six-plus call sites in this repo used to hand-roll independently: "detect the toolchain, run something, read pass or fail." It replaces the ad hoc version in each of those with one shared ladder. > **This `SKILL.md` is a thin index.** Detailed rules live in `rules/*.md` and load on demand. --- ## The execute-not-score boundary This skill **does not score** — it never assigns a confidence score and never grades pass/fail against an intent. It runs a command, captures the raw output, and classifies the result against the *claim itself* as `confirms` / `contradicts` / `ambiguous` / `null`. - `confidence(code)` owns the number — this skill supplies sharper evidence to that gate, it does not replace it. - A calling agent's own grading (e.g. `bug-fix-verifier`'s `FAIL_TO_PASS`, the `aw-executor` Phase 4 `expect` comparison) stays with the caller — this skill supplies the run-and-observe mechanic underneath that grading, not the grading itself. See [`rules/receipt.md`](./rules/receipt.md) for the full contract, including the hard invariant that a null or non-reproducing result **drops or contradicts** a finding and is never confirmation. --- ## The two consumer shapes | Shape | Question it answers | Consumers | | --- | --- | --- | | **Clai...