/local-merge

Merge a branch into a target branch via a disposable shallow clone, then propagate to the primary worktree non-destructively. Defaults to main if no target specified.

Inputs

Input	Required	Default	Example
BRANCH	yes	—	feat/local-merge-skill
TARGET	no	main	develop, release/v2
PRIMARY	no	First line of git worktree list	/Users/you/projects/repo
MESSAGE	no	merge: $BRANCH into $TARGET	merge: feat/auth into main

Phase 1 — Remote Merge (mechanical)

All commands are explicit. No reasoning required.

1a. Calculate clone depth

git fetch origin "$TARGET" "$BRANCH"
DEPTH=$(( $(git rev-list --count origin/"$TARGET"..origin/"$BRANCH") + 10 ))

1b. Clone, merge, push

Validate inputs before shell interpolation — branch names must match git's allowed character set:

# Validate branch names (reject shell metacharacters)
case "$BRANCH$TARGET" in *['$`\!']*) echo "Invalid branch name"; exit 1 ;; esac

MERGE_DIR="${CLAUDE_SESSION_DIR:-$TMPDIR}/local-merge"
[ -d "$MERGE_DIR" ] && rm -rf "$MERGE_DIR"
git clone --depth "$DEPTH" --branch "$TARGET" "$(git remote get-url origin)" "$MERGE_DIR"

git -C "$MERGE_DIR" fetch origin "$BRANCH"
git -C "$MERGE_DIR" merge FETCH_HEAD -m "$MESSAGE"
git -C "$MERGE_DIR" push

1c. Non-fast-forward recovery

git -C "$MERGE_DIR" pull --rebase
git -C "$MERGE_DIR" push

Max 3 retries. After 3 failures, stop and report. Do not force-push.

1d. Cleanup

Always runs after Phase 1, success or failure:

rm -rf "$MERGE_DIR" 2>/dev/null || true

If rm -rf is denied (sandbox, permission prompt), log it and move on — the temp dir is in $TMPDIR and will be cleaned by the OS. Do not block the merge on cleanup failure.

Phase 2 — Propagate to Primary (reasoning required)

Bring the primary worktree's $TARGET up to date with the newly-pushed remote. Steps 2a-2c are mechanical. Step 2d requires agent judgment. Steps 2e-2g depend on that judgment.

2a. Guard: is primary on TARGET?

git -C "$PRIMARY" branch --show-current

Not on $TARGET? Stop. Report: "Primary is on <branch>, not $TARGET. Remote updated; local not forwarded." Done.

2b. Protect dirty state

git -C "$PRIMARY" status --porcelain

If output is non-empty, shelter uncommitted work. Use add -u (tracked files only) to avoid staging sensitive untracked files (.env, credentials):

git -C "$PRIMARY" add -u
git -C "$PRIMARY" commit -m "wip: preserve local state before remote sync"

Record WIP_CREATED=true for step 2g. If clean, skip.

2c. Fetch updated TARGET

git -C "$PRIMARY" fetch origin "$TARGET"

2d. Analyze divergence (agent reasoning)

Run all five commands, then assess using the decision matrix:

git -C "$PRIMARY" rev-list --count HEAD..origin/"$TARGET"    # commits behind
git -C "$PRIMARY" rev-list --count origin/"$TARGET"..HEAD     # commits ahead
git -C "$PRIMARY" diff HEAD..origin/"$TARGET" --stat          # changed files
git -C "$PRIMARY" log HEAD..origin/"$TARGET" --oneline        # incoming commits
git -C "$PRIMARY" log origin/"$TARGET"..HEAD --oneline        # local-only commits

Behind	Ahead	Assessment	Action
N > 0	0	Fast-forward	--ff-only (2e)
N > 0	M > 0	Diverged	Inspect diff for file overlap + semantic risk (2e)
0	0	Already current	Skip, report, done
0	M > 0	Local-only commits	Unexpected — escalate to copilot (2f)

Beyond textual conflicts, assess semantic risk: two agents editing related config in different files can silently break things even when git sees no conflict.

2e. Execute merge

Fast-forward (behind > 0, ahead = 0):

git -C "$PRIMARY" merge --ff-only origin/"$TARGET"

Non-conflicting divergence (different files, low semantic risk):

git -C "$PRIMARY" merge origin/"$TARGET" --no-edit

If merge produces conflicts, abort immediately:

git -C "$PRIMARY" merge --abort

Then escalate to copilot (2f).

Uncertain or risky: do not attempt merge. Go to 2f.

2f. Copilot escalation

1. Invoke /copilot to enter copilot mode
2. Present the analysis from 2d: behind/ahead counts, diff stat, commit logs
3. State what blocked automatic resolution
4. Let the user drive the merge
5. When resolved, invoke /autonomous to restore previous mode

2g. Restore WIP state

Only if WIP_CREATED=true:

git -C "$PRIMARY" reset --soft HEAD~1

Preserves all changes in the index and working tree exactly as they were before the skill ran.

Safety Invariants

• No force-push. Non-fast-forward retries use pull --rebase, never --force.
• No work lost. Dirty state is WIP-committed before any merge, restored after.
• No direct commits to main. Phase 1 uses a disposable clone for multi-agent isolation regardless of target. Phase 2 only fast-forwards or merges from origin.
• Conflict = stop. Conflicts trigger merge --abort and copilot escalation, never auto-resolution.
• Cleanup always runs. The shallow clone is removed regardless of outcome.

Integration

Caller	Context
/ship	CI-down path after review approval
/reflect	Post-task consolidation to main
/copilot	Receives escalation from Phase 2f
/autonomous	Restored after copilot resolves conflict