/rollback-from-artifact

Execute the rollback plan documented in a side-effects artifact. Side-effects artifacts (upgrades/side-effects/*.md) carry a §7 "Rollback cost" section that names the back-out path for the change. When an incident requires reverting a specific change, this skill reads that section and drives the rollback.

When this fires

• A pr-gate change lands and produces observable regressions (false blocks, secrets leakage, replication incoherence).
• A release commit needs to be reverted and its side-effects artifact names the rollback steps.
• Echo's automated incident detection raises a rollback-requested Attention Queue entry with an artifact pointer.

Not user-invocable: the skill runs under explicit incident-response context, never conversationally.

Inputs

• Artifact path — upgrades/side-effects/<slug>.md on the instar repo's main branch.
• Incident reason — one-line human description of why rollback is triggered.
• Authorization — Justin's explicit approval (comment, Telegram message, or dashboard action).

Procedure

1. Fetch and validate the artifact.

   • Check that the file exists on main.
   • Extract the §7 "Rollback cost" section.
   • Refuse to proceed if the section is missing, empty, or the artifact's referenced commit SHA is not findable in git log.

2. Identify the target commit.

   • Use the artifact's slug or commit-hash reference to locate the specific commit to revert.
   • Verify no newer commits depend on it via git log --oneline <SHA>..HEAD -- <touched-files>.

3. Prepare the revert.

   • Create a worktree branch: revert/<slug>-<timestamp>.
   • Run git revert <SHA> (NOT reset — preserves history).
   • If revert produces conflicts, STOP and file an Attention Queue entry with the conflict details.

4. Run the layered checks.

   • npm run lint / npx tsc --noEmit — must be clean.
   • Vitest on any test suites the artifact's "Evidence pointers" references — must pass.
   • Any post-revert cleanup steps the artifact's §7 enumerates (data migration, state repair).

5. Open the rollback PR.

   • PR title: revert: <original-slug> — incident response.
   • PR body: link to the artifact, the incident reason, the verified-clean test output, and the list of any follow-up operational steps.
   • Apply label incident-rollback if it exists.

6. Post-merge verification.

   • After the PR merges, monitor for the original regression to stop reproducing.
   • Update the original artifact to add a §"Rollback executed" postscript with timestamp, incident summary, and verification notes.

Hard rules

• Never --force-push to main or any shared branch during rollback. If the revert produces an unclean state, file an Attention Queue entry and escalate to Justin.
• Never skip the artifact's "Rollback cost" section — if it's ambiguous or missing, that's a precondition failure; do not extrapolate.
• Never revert a commit whose side-effects artifact is marked approved-by: null or lacks an artifact entirely — those indicate unknown rollback semantics.

Related

• /instar-dev — the skill that produces rollback-able artifacts.
• /build — quality gates shared with rollback verification.
• docs/signal-vs-authority.md — the principle that forbids making rollback decisions from brittle signals alone; rollback is always a human-authorized action on a well-documented artifact.