inherit

Mental model: "I am the child. I want what my parent has."

Brings the current branch (and optionally its descendants) up to date with its parent. Inbound counterpart to /ship (outbound to a target) and /isolate (forks a new child from a parent).

When to use

• Current branch is stale relative to its base.
• A stack of dependent branches needs the parent's latest commits cascaded down.
• Web sessions or minimal environments where wt, git-trim, gh aren't available.

Do NOT use to send changes upward — that's /ship. Do NOT use to create a new branch — that's /isolate.

Why merge, not rebase

Autonomous mode's git-rewrite-guard.sh blocks git rebase, --amend, reset --hard, and push --force*. Merge is also the parallel-worktree community standard for syncing from base — non-destructive, composes with stacks, never requires a force-push, safe under shared checkouts. Always git merge, never git rebase in this skill.

Constraints

• Pure git only. No wt, git-trim, or gh for the merge step. Works in web sandboxes.
• Always git -C <abs-path> for state-mutating ops. cd does not persist between Claude Code Bash calls; bare git from session CWD hits the primary worktree.
• Never auto-resolve conflicts. The user owns conflict resolution.

Inputs

CI-down signal: same convention as /ship — if user has signaled CI is down, substitute /local-merge for each git push.

Procedure

1. Resolve current branch + repo root

REPO="$(git rev-parse --show-toplevel)"
CURRENT="$(git -C "$REPO" rev-parse --abbrev-ref HEAD)"

Pre-flight aborts:

• CURRENT is HEAD (detached) → "No current branch — checkout a branch first."
• Working tree dirty (git -C "$REPO" status --porcelain non-empty) → "Commit or stash local changes before inheriting."

2. Detect parent (unless --parent was passed)

PARENT=$(git -C "$REPO" reflog show HEAD --pretty=format:'%gs' \
  | grep -m1 '^branch: Created from ' \
  | sed -E 's/^branch: Created from //; s|^origin/||')
PARENT="${PARENT:-main}"

• grep -m1 picks the most recent "Created from" — that's the actual fork point.
• Strip leading origin/ so we work in branch-name space.
• Fall back to main when reflog is empty (web sessions, fresh clones, branches created via fetch). Tell the user it was a fallback so they can correct via --parent.
• If PARENT == CURRENT after resolution → "Already on parent branch; nothing to inherit."

Echo before mutating: Detected parent: <PARENT> (current: <CURRENT>). Inheriting from origin/<PARENT>.

3. Fetch the parent

git -C "$REPO" fetch origin "$PARENT"

If fetch fails (offline, ref missing, parent deleted on origin): surface the error verbatim. Do NOT silently substitute another branch.

4. Merge parent into current

git -C "$REPO" merge --no-edit "origin/$PARENT"

Outcomes:

• Clean (real merge or fast-forward) → proceed.
• No-op (already up to date) → say so plainly and skip the push.
• Conflict → stop, show git status, list conflicted paths, hand control back. Do NOT attempt automatic resolution.

5. Cascade through stack (only if --stack)

A "dependent" is a local branch with CURRENT as an ancestor. The user supplies the candidate set after --stack (or names them inline); don't guess silently — if the user didn't name them, ask once.

Order: bottom-up, parent-first. Use pairwise git merge-base --is-ancestor to find topological order — at each step, pick a branch in the remaining set that no other remaining branch is an ancestor of. That branch goes next:

# B is downstream of A iff A is an ancestor of B
git -C "$REPO" merge-base --is-ancestor "$A" "$B"  # exit 0 = yes

For each branch in that order, merge its direct parent in the chain (the previous branch processed) — NOT origin/main again. The whole point of cascading is that the parent already absorbed main, and now the child absorbs the updated parent:

PREV="$CURRENT"
for child in "${ordered[@]}"; do
  git -C "$REPO" checkout "$child"
  git -C "$REPO" merge --no-edit "$PREV"   # stop on conflict
  PREV="$child"
done
git -C "$REPO" checkout "$CURRENT"

On conflict: stop the cascade. Report which branch wedged and which paths conflict. Do NOT skip forward.

6. Push (or /local-merge if CI is down)

For each branch that received commits (CURRENT plus any cascaded children):

git -C "$REPO" push origin "$BRANCH"

If user has signaled CI is down: invoke /local-merge per branch instead. If --no-push was passed: skip entirely; tell the user the branch(es) have local merge commits awaiting publish. If push is rejected (remote moved): do NOT force. Report the rejection; the user decides whether to re-run /inherit.

7. Report

Concise summary, not paragraphs:

Inherited from <PARENT> into:
  - <CURRENT>   (merge <sha>, pushed)
  - <child-1>   (merge <sha>, pushed)

On conflict:

Inherit halted on <branch>: conflicts in <files>. Resolve, commit, then re-run /inherit.

Quick reference

Failure modes — explicit counters

Red flags — STOP

• About to type git rebase, --amend, reset --hard, or --force → wrong skill.
• Parent detection silently returned empty and you didn't fall back to main.
• Merging top-down through a stack (parent-most last) → reverse the order.
• Bare git without -C from session CWD on a non-primary worktree.
• Modifying files outside git operations — this skill is pure git.

Companion skills

• /isolate — forks a new child off a parent.
• /inherit (this skill) — pulls parent → child. Inbound.
• /ship — pushes child → target. Outbound.

Three directions a branch moves: fork off, sync down, ship up.

Example invocations

• "pull main into this branch" → /inherit
• "update my stack from main" → /inherit --stack
• "sync from base but don't push yet" → /inherit --no-push
• "catch up to develop instead of main" → /inherit --parent develop