codifylisted

# Skill — Codify > Every mistake compiles into a rule. Codify is that compile step: it takes the thing that just went > wrong and produces a *reviewable proposal* for the rule that would make the class of mistake > impossible or caught — carrying the incident that motivated it. _(Provenance: compounding engineering > — Every; the mistake→rule-with-provenance loop — agentic craft, Hashimoto. See > [`../../operating/evolution.md`](../../operating/evolution.md).)_ ## When to use it - An incident or near-miss just happened that could recur. - A review comment keeps reappearing across PRs — a pattern, not a one-off. - A postmortem or handoff names a lesson worth making permanent. Not for one-offs (those belong in the task) and not for standing rules that already exist (those belong in [`../../operating/`](../../operating/) as doctrine). A lesson that will not recur is not a rule. ## The pass 1. **Name the incident and link it.** A proposal without a triggering incident is usually taste, not a rule. **When the incident cannot leave its owner's layer** — it belongs to a team, a customer, or a confidentiality boundary — the rule still carries its shape: strip the names, tickets, paths, and domains, and keep the concrete failure that motivated it, which is the inputs, the wrong outcome, and why the obvious guard misses it. The bar is that an implementer who never saw the incident can still write the rule's test. **Generic must never decay into vague**: a rule that