pr-merge-runner

name: pr-merge-runner description: > Auto-merge PRs after pr-cleaner-master. Processes only open PRs whose last pr-cleaner verdict is merge, oldest first: post Thanks + /lgtm + /approve, wait for ci-bot squash merge, git pull origin main, skip on any blocker. Never rebase, retest, or fix CI. Always skip workflow-file PRs. Use when: "merge safe PRs", "auto merge", "ship merge rows", "pr-merge-runner", "/pr-merge-runner", after pr-cleaner when user wants hands-off landing. Chains after pr-cleaner-master; does not replace review. argument-hint: "[#PR|PR...] [--repo owner/repo] [--dry-run] [--fresh]"

PR Merge Runner

Companion to pr-cleaner-master. That skill classifies; this skill lands only rows already marked merge. The user invoking this skill is the confirmation gate — no second approval step.

This skill does not run deep review (use pr-cleaner-master or pr-eval). It does not fix code, rebase branches, retest CI, or call gh pr merge.

Use the loaded skill base directory as SKILL_DIR.

Argument Parsing

Resolve target repo:

1. If --repo given → use it.
2. Else → gh repo view --json nameWithOwner --jq .nameWithOwner.
3. If neither works → error: "Not in a GitHub repo. Pass --repo owner/repo."

Phase 0: Load Snapshot ⛔ BLOCKING

Same path as pr-cleaner-master:

~/.claude/projects/<project-dir-slug>/pr-cleaner-state.json

• <project-dir-slug> matches the memory-system slug for the current project root.
• If missing or repo mismatch → treat as {}.
• With default --from-snapshot: candidate PR numbers are keys in snapshot.prs where verdict == "merge". Still must pass live preflight (PR may have closed, CI may have regressed).
• With --fresh: candidate set = all open non-draft PRs from batch fetch.

If --from-snapshot yields zero candidates → print No merge-verdict PRs in snapshot. Run pr-cleaner-master first. and exit.

Phase 1: Batch Fetch ⛔ BLOCKING

Fetch metadata for every candidate (and all open PRs when --fresh):

gh pr view <number> --repo <repo> --json \
  number,title,author,createdAt,headRefOid,mergeable,mergeStateStatus,\
state,isDraft,reviewDecision,labels,updatedAt,additions,deletions,changedFiles,\
statusCheckRollup,comments

Or list all open when building --fresh set:

gh pr list --repo <repo> --state open --limit 100 --json \
  number,title,author,createdAt,headRefOid,mergeable,mergeStateStatus,\
state,isDraft,reviewDecision,labels,updatedAt,additions,deletions,changedFiles,\
statusCheckRollup,comments

Sort candidates by createdAt ascending (oldest first).

Phase 2: Preflight ⛔ BLOCKING

For each candidate, first failing rule → skip (record reason, continue). Do not attempt any fix.

Workflow-file gate (always skip)

Bot merge fails when the PR updates workflow files without workflows permission (e.g. .github/workflows/ci-bot.yml). Detect before commenting:

gh pr diff <number> --repo <repo> --name-only | rg '^\.github/workflows/'

Any match → skip with workflow-permission. Never add a bypass flag.

Hard prohibitions

• Never gh pr update-branch, rebase, merge main into PR, or /rebase.
• Never /retest, fix CI, or push commits to the PR branch.
• Never gh pr merge, gh pr review --approve, or close PRs.
• Never post /merge as a fallback (comment body is fixed; see Phase 3).

Phase 3: Execute Merge Loop ⚠️ REQUIRED

Process preflight-pass PRs one at a time (oldest first). Parallel batching is forbidden unless the user explicitly says several named PRs may run together in the same turn — default remains serial.

For each PR:

Step A — Comment (exact three lines)

gh pr comment <N> --repo <repo> --body "$(cat <<'EOF'
Thanks @<author>!
/lgtm
/approve
EOF
)"

Replace <author> with author.login. No other text. No code blocks.

Skip Step A in --dry-run (log the would-be body instead).

Step B — Wait for merge

Poll every 10 seconds, up to 36 attempts (~6 minutes):

gh pr view <N> --repo <repo> --json state,mergedAt --jq '.state'

• MERGED → Step C.
• Still OPEN after 36 polls → skip timeout, next PR.
• CLOSED without merge → skip not-open, next PR.

Do not post again on timeout.

Step C — Sync local main

git pull origin main

Run from the current git workspace root. Skip in --dry-run.

Step D — Record

Append to in-memory results: { number, title, author, mergedAt }.

Then continue to the next PR.

Phase 4: Report ⚠️ REQUIRED

## PR Merge Runner — <repo>  (<UTC timestamp>)

### Merged (N)

| PR | Author | Title |
|---|---|---|
| #517 | @alice | fix: … |

### Skipped (M)

| PR | Reason | Note |
|---|---|---|
| #520 | workflow-permission | touches .github/workflows/ |
| #516 | ci-fail | gateway / e2e failed |

Local main: `<git rev-parse --short HEAD>` (after last pull)
Dry run: yes/no

Skip reason codes (use exactly):

Phase 5: Update Snapshot

After the run, update pr-cleaner-state.json for every candidate seen:

"123": {
  "headSha": "...",
  "comments": 4,
  "verdict": "merge",
  "mergeResult": "merged",
  "skipReason": null,
  "at": "2026-06-10T18:00:00Z"
}

• mergeResult: "merged" | "skipped" | "dry-run"
• skipReason: null when merged; otherwise the code above.

Atomic write: <path>.tmp then rename. Same repo key as pr-cleaner.

Chaining With pr-cleaner-master

Typical maintainer flow:

1. /pr-cleaner-master — classify, user reviews Action table.
2. /pr-merge-runner — land every snapshot merge row that still passes preflight.

pr-cleaner-master never merges; this skill never re-classifies.

Do Not

• Never fix, rebase, retest, or manually merge.
• Never merge PRs not marked merge in snapshot (unless --fresh).
• Never merge PRs that touch .github/workflows/**.
• Never paste code to contributors.
• Never parallelize by default.
• Never skip the final Merged/Skipped report.
• Never claim CI is green without checking statusCheckRollup.