merge-down

name	merge-down
version	1.0.0
description	Use when the user is inside a parallel stream (worktree branch) and wants to bring that branch up to date with the LATEST of its parent branch — typically after one or more sibling streams have merged their work up into the parent (via /merge-up). Pulls the parent's accumulated commits down into the current branch with a true merge. Inverse of /merge-up; the parent is recorded by /parallel-work in git config (branch.<name>.exosuitParent). Read-only on the parent — safe to run while the parent worktree is busy.
trigger	manual
depends-on	[]
references	[]
disable-model-invocation	true
user-invocable	true
allowed-tools	Read, Glob, Grep, Bash, AskUserQuestion
argument-hint

---

merge-down

Bring the current stream's branch up to date with the parent it was created from. Use it after a round of /merge-ups have landed sibling streams' work on the parent: each sibling still only has its OWN commits, so run this in each stream to integrate everyone else's merged work.

This is the complement of /merge-up:

• /merge-up — merge THIS branch into the parent (publish your work upward).
• /merge-down — merge the parent into this branch (pull everyone's work downward).

Because all worktrees of a repository share one object store and one set of branch refs, the parent ref already reflects every local /merge-up — no network fetch is needed for local merges. A fetch is only relevant if merges were pushed from another machine (Step 3 handles that optionally). This skill never writes to the parent's working tree, so it is safe to run even while the parent worktree is in use.

Step 1 — Identify branches

B="$(git rev-parse --abbrev-ref HEAD)"
echo "current branch: $B"

• If B is HEAD (detached), STOP — tell the user to check out a branch.
• Resolve the parent P:

  P="$(git config "branch.$B.exosuitParent" || true)"
  

  • If empty, fall back to stripping the last -<suffix> (e.g. sprint-3-a → sprint-3) and verify it exists: git show-ref --verify --quiet refs/heads/<cand>.
  • If still unresolved or ambiguous, ASK the user which branch is the parent.
• If P == B or P doesn't exist, STOP and report.

Step 2 — Pre-flight cleanliness (current worktree only)

git status --porcelain            # current worktree — must be empty

• If dirty, STOP: merging the parent in could collide with uncommitted work. Tell the user to commit or first, then re-run.