Split PR

Turn one oversized PR (or local branch) into a few small, reviewer-aligned PRs — and leave the original PR gracefully retired.

This skill uses GitHub's native stacked pull requests via the gh-stack CLI extension (gh extension install github/gh-stack) instead of hand-rolled branch chains. GitHub now owns the stack: it retargets and cascades base branches automatically on merge, so the old failure mode this skill used to guard against — a squash-merged parent leaving its child PR full of stale commits, requiring a manual rebase --onto — no longer happens. Verify the extension is installed (gh extension list | grep gh-stack) before starting; if missing, install it first.

Hard rules

• Exactly one pause: the split-plan approval in Step 2 (which includes the independent-vs-stacked choice). After approval, run to completion autonomously.
• Never discard work. No destructive git (reset --hard, clean, branch deletion, manual force-push, history rewrite). Record a backup ref before creating any branch.
• Clean working tree required — this skill splits committed work only. If git status --porcelain is non-empty, stop and ask the user to commit or stash first.
• Stage only named files or hunks. Never git add . / git add -A. When using gh stack add -A, that rule doesn't apply — see Step 4.
• Never skip or bypass commit hooks (no --no-verify, no SKIP).
• Force-push is scoped to gh-stack. gh stack push / sync / rebase force-push with --force-with-lease as a normal part of cascading rebases — that's expected and safe on branches this skill created. Never run a manual git push --force yourself, and if any slice branch has commits you didn't make (a reviewer pushed a fixup directly to it), stop and confirm with the user before running sync or rebase on that stack.
• Commit messages and PR bodies: plain, direct, neutral voice. State what changed, not what you're about to do.
• Use gh CLI for all GitHub operations (PR reads/writes, stack management). If a GitHub MCP server is connected in-session, prefer it for read-only lookups, but gh remains the tool of record for mutations since gh-stack itself is a gh extension.

Step 1 — Discover the work