branch-cleanup

Report stale remote branches and propose safe deletion. Never delete a branch without explicit authorization for that batch.

What this skill is NOT for

• Local git worktree management (git worktree add, list, prune) — out of scope.
• One-time repository merge-default and branch-protection setup — use /gh-bootstrap. This skill only reads delete_branch_on_merge and existing rulesets; it proposes turning the setting on but the write happens through gh api -X PATCH, the same endpoint /gh-bootstrap uses in its step 2.

Protocol

1. Check delete-branch-on-merge

REPO="$(gh repo view --json nameWithOwner --jq '.nameWithOwner')"
gh api "repos/$REPO" --jq '.delete_branch_on_merge'

If false, propose enabling it and explain the effect: GitHub deletes a branch's remote ref automatically once its pull request merges. Ask for explicit authorization before running the gh api -X PATCH repos/{owner}/{repo} -F delete_branch_on_merge=true write — see /gh-bootstrap step 2 for the full merge-defaults PATCH, which this skill does not duplicate.

2. Report stale branches

Run the bundled script from the repository root:

python3 "$BRANCH_CLEANUP_HELPER" --days 90 --github "$REPO"

Resolve BRANCH_CLEANUP_HELPER from the loaded SKILL.md directory (scripts/stale_branches.py), resolving symlinks first. For each remote branch the script reports:

• Last commit date and author (git log -1).
• Ahead/behind counts against the default branch (git rev-list --left-right --count).
• Merged status (git branch -r --merged <default>).
• Whether an open pull request targets the branch (gh pr list --head <branch> --state open --json number), when --github is passed.
• Whether a ruleset protects the branch (gh api repos/{owner}/{repo}/rules/branches/ {branch}), when --github is passed.

The output is a table sorted by age (oldest first) with a recommendation column of keep, archive, or delete. See references/policy.md for the exact classification rule.

3. Local hygiene

Report-only, no deletion:

git fetch --prune
git branch --merged <default>

List the locally merged branches for the user. Do not delete local branches without the same per-batch authorization required in step 4.

4. Deletion is never automatic

For every branch classified delete, print the exact command:

git push origin --delete <branch>

Always exclude the default branch, any protected branch, and any branch with an open pull request from deletion — the script enforces this by classifying those branches keep regardless of age. Require explicit user authorization before running any printed command, and confirm the authorized batch matches the printed list exactly.

5. Optional scheduled report workflow

Copy assets/stale-branch-report.yml to .github/workflows/stale-branch-report.yml if the user wants a recurring report. It only writes a job summary — it never deletes a branch. actions/checkout is pinned by SHA.

6. Verify

Re-run the script and confirm the printed table matches the branches actually present on the remote (git branch -r). Confirm no delete recommendation includes the default branch, a protected branch, or a branch with an open pull request.

Cross-references

• /gh-bootstrap — one-time repository merge defaults and branch-protection rulesets.
• /prek — local pre-commit hook checks, unrelated to branch lifecycle.
• /oss-hygiene — broader repository health, including community-standards files.