The Speccle loop.

A feature, in any form.

Prose, a ticket, a half-formed idea — or existing code you want brought under governance. implement-feature takes the first three; carve-feature takes the last, deriving the spec from what the code observably does.

SPEC.md + CONTEXT.md, in the feature folder.

One directory owns the whole vertical slice: acceptance criteria as H2 headings — ## [KEY-n] followed by one testable statement — with free-form bodies for rationale and edge cases, and a CONTEXT.md holding the feature's language and cross-criterion decisions.

Nine fixed rules over the criteria.

Structural rules police keys and ids; quality heuristics judge the heading statement only — weasel wording, compound criteria, unmeasurable outcomes. One severity, no configuration: a spec lints clean or it doesn't.

The pause where you own the criteria.

Nothing gets built until you ratify the criteria. Every skill that drafts a criterion stops here — before the first test of a new slice, before a human-path test in strengthen, before a carved spec is claimed.

Tagged tests and green code, one criterion at a time.

A test claims a criterion by carrying its [KEY-n] token anywhere in its full name — one describe block claims every test inside it. The tracer criterion goes end-to-end first; done means lint clean, every criterion claimed, all tests green.

Mutation + coverage → the per-criterion heatmap.

strength joins the specs with a Stryker mutation report and a coverage summary into killed ÷ covered per criterion. A criterion below 100% always lists its surviving mutants — the exact code changes no test noticed — with line coverage alongside as the naïve baseline.

Every surviving mutant routed — never the score.

Each survivor is judged on what it breaks, not on what it does to the number. The routing decides who acts next: the agent when a criterion already promises the behaviour, you when the spec needs sharpening.