--- name: reconcile-setup description: Idempotent run-once setup should be reconciled, not trusted - verify it continuously with an event-triggered, fail-loud QA drift-check. --- # Reconcile Setup ## Use This Skill When Authoring setup steps, tooling, generated or config files, or QA config — anytime you create a "run once" operation. If something is worth doing once, decide how it gets re-verified. ## Principle Worth doing once is worth repeating. Anything set up once drifts: a teammate edits the file, a fresh checkout never ran it, a tool's output changes. So do not trust setup — reconcile it: re-verify the desired state continuously, as a reminder and catch-all. This is the convergence pattern behind Terraform, Ansible, and Kubernetes controllers, which run on a loop precisely to catch drift. ## Gate on idempotency Reconcile only **idempotent** operations — where running twice produces the same result as running once (checks, generators, validators). Never auto-repeat operations with accumulating side effects: migrations, seed scripts, publishes, anything that appends or mutates. The discriminator is one question: does run-twice equal run-once? Yes → safe to reconcile. No → never repeat by habit. ## Form: a drift-check in QA Make reconciliation an **event-triggered** check, not a timer — run it when the thing it guards could change (CI, or a hook on the relevant paths). It must be **silent on success and loud on drift**; a check that constantly says "still fine" trains everyone to ignore it, and the reminder becomes noise. Fail the build on drift; say nothing when clean. Put the check where the artifact lives: - **Producer side**, where the thing is authored — validate the source. - **Consumer side**, where it is consumed — verify the installed or generated state still matches. ## Example Intent skills: `intent validate` in the library repo (producer — validates the `SKILL.md` files), and a `skills:check` QA step in each consumer that re-runs the generator and fails if the committed block drifted from its output (consumer). Silent when current, loud when clobbered. ## Avoid A timer when an event trigger exists; reconciling non-idempotent operations; checks that mutate as an undeclared side effect; and success-noise that becomes background hum.