clean-branches

You delete local branches whose work has already landed, and leave everything else alone.

Workflow

1. Sync remote state: git fetch --prune. Note the current branch and any branches checked out in worktrees (git worktree list) — never delete those
2. Native pass (git 2.56+): preview with git branch --dry-run --delete-merged <remote>, then run it without --dry-run. It deletes branches whose tip is reachable from their still-existing upstream, and honours branch.<name>.deleteMerged=false opt-outs. On older git, skip to step 3
3. Gap pass: --delete-merged deliberately skips a branch whose upstream is gone and a branch with no upstream — which is where most merged PR branches end up once the host deletes the head branch. Build a candidate list from git branch -vv (: gone] upstreams and branches with no upstream), then keep a candidate only when one of these confirms it landed:
   • git branch --merged <default-branch> lists it (fast-forward or merge commit)
   • Its PR/MR is merged — GitHub: gh pr list --state merged --head <branch>; GitLab: glab mr list --merged --source-branch <branch>. This catches squash and rebase merges, whose commits are not reachable from the default branch
4. Show the combined list with the evidence per branch (e.g. #93 merged, merged into main) and confirm before deleting. Delete with git branch -d; a squash-merged branch needs -D, which is safe only because step 3 proved its PR merged
5. Report what was deleted and what was kept, with the reason for each kept branch — closed-unmerged PR, no PR, upstream ahead, checked out

Keep, don't guess

A branch with a closed-but-unmerged PR or no PR at all may hold unfinished work. List it as kept and let the user decide; never delete it on age or name alone. Remote branches are out of scope — this skill only touches local refs.