worktrees

name

worktrees

description

Set up and operate git worktrees for isolated, parallel development — running multiple branches or Claude sessions at once without stashing or branch-switching, reviewing a PR while developing, comparing implementations side by side, or giving a risky change its own clean checkout. Use this whenever the user mentions worktrees, "isolated workspace", "parallel branches", "work on two things at once", `git worktree`, `--worktree`, or before executing a multi-step implementation plan that should not touch the current working tree. Also use when you (the agent) need an isolated checkout to make file changes that must not collide with the user's working tree.

Git Worktrees

A git worktree is a second working directory with its own files and branch that shares the same repository history and remote as your main checkout. Worktrees let you have several branches checked out at once — edits in one never touch another — without stashing, cloning, or constantly switching branches.

Core principle: one worktree per active task. Switch context by changing directories, not branches. A branch can only be checked out in one worktree at a time.

When NOT to bother: a quick read of another branch (git show branch:file), a one-line fix on a clean tree, or anything where switching branches costs nothing. Worktrees pay off when you have uncommitted work to protect or parallel work to run.

Agent Start Gate (required before writing code in an existing worktree)

A real incident: an agent hit a build error that was already fixed on origin/main — the local worktree was just 17 commits behind and never got the fix. Before any implementation in a worktree you didn't just create fresh, verify all of the following (or run npm run worktree:health, which checks the first two automatically):

• Not behind origin/main beyond what you're deliberately working from an older base for. git fetch origin && git rev-list --left-right --count HEAD...origin/main.
• No stale known-bad patterns — e.g. rg 'from "\.\./\.\./\.\./\.\./config/groq-models\.json"' app/src/lib/ai/provider.ts (the pre-IPI-428 bug; worktree-health.mjs checks this by default).
• Correct worktree for the task — git branch --show-current matches what you intend to work on.
• State is clean, or intentionally dirty — git status --short; know what's yours before touching anything.
• Docs/specs aren't "missing" due to staleness — if a file exists on origin/main but not locally, that means the checkout is stale, not that the doc needs recreating. Verify with git show origin/main:<path> before concluding a doc is missing, and never recreate a doc without first fetching/rebasing to confirm it's genuinely absent upstream.
• .claude/skills/ gitignore state matches upstream — git check-ignore -q .claude/skills/ exiting 0 (ignored) means this checkout predates the skills-tracking rollout (PR #234) and is running an old ignore rule; rebase before assuming local skill edits will ever be trackable. (A plain grep against .gitignore text would miss commented, negated, or reformatted rules — check-ignore asks git the real answer.)

If any check fails: stop and report it, don't route around it. Fetching/rebasing is the fix; patching around a stale symptom (like re-adding a "fixed" bug's workaround) just reintroduces the original problem in a new place.

node scripts/worktree-health.mjs              # gate before starting work (current worktree)
node scripts/worktree-health.mjs --all        # audit every registered worktree
node scripts/worktree-health.mjs --pre-delete  # gate before `git worktree remove` (see Backup before cleanup)

iPix defaults

For iPix work, use a worktree for any multi-step implementation task (anything beyond a trivial one-file edit) so the current working tree stays clean. Prefer the native flow (claude --worktree, EnterWorktree); when creating manually, follow these conventions:

• Branch: ipi/<task-id>-<short-name> — e.g. ipi/22-ui-shell
• Directory: ../wt-ipi-<task-id>-<short-name> (sibling of the repo) — e.g. ../wt-ipi-22-ui-shell

# Preferred — repo script (naming, nested guard, .worktreeinclude, npm ci)
npm run worktree:add -- IPI-286 route-aware-sections
cd ../wt-ipi-286-route-aware-sections

# Manual equivalent
git fetch origin main
git worktree add ../wt-ipi-286-route-aware-sections -b ipi/286-route-aware-sections origin/main
cd ../wt-ipi-286-route-aware-sections
# copy env: see .worktreeinclude (or npm run worktree:add does this)
cd app && npm ci && cd ..

Before adding: npm run worktree:audit — check count, orphans, merged/stale trees (docs/development/worktree-tracker.md).

Default validation — run in the worktree, matched to changed paths (pr-workflow verify-matrix):

Changed	Commands
app/** (most iPix tasks)	cd app && npm ci && npm run lint && npm run typecheck && npm test · npm run build when routes/config/env/middleware touched
supabase/**	infisical run -- npm run supabase:verify · infisical run -- npm run supabase:verify-rls (+ conditional scripts per matrix)
Legacy src/** (retiring)	infisical run -- npm run build && npm run test
Docs-only	No app build required — still run forensic audit

Root package.json has no lint/test/build — those live under app/. Pre-push hook runs root typecheck/tests only where configured; operator PRs gate on app/ scripts.

Hard rules (iPix):

• Never push to main — branch ipi/<id>-<slug>, PR to main only (CLAUDE.md).
• One concern per PR — split before staging (pr-workflow).
• Forensic verify before Done — task-verifier in the worktree.

iPix safety rails

Always-on guardrails for iPix worktree work. Command recipes for the longer ones live in references/ipix-ops.md.

Merge gate checklist

Before opening a PR, merging, or flipping a task to Done — all must hold, or it's "looks done" but broken:

• Area verify matrix green (pr-workflow) — typically cd app && lint · typecheck · test (+ build if applicable)
• Supabase verify when supabase/** touched (infisical run -- npm run supabase:verify*)
• Forensic audit clean — no unexpected dirty or untracked files
• Production SHA check — base is current origin/main, local main not diverged
• No leaked dirs in the diff (see Leak guard below)
• PR scoped to one concern (PR splitting playbook)
• task-verifier report attached for IPI/SCR ship gates
• Worktree backed up if it held uncommitted work, and npm run worktree:pre-delete clean before removal (Backup-before-cleanup below)

Never run blindly

These discard work or rewrite history. Run the forensic audit first and only proceed once you can name exactly what will be lost:

• git worktree remove --force — discards a worktree's uncommitted changes + untracked files
• git clean -fdx / rm -rf — deletes untracked files (incl. .env) / arbitrary trees
• git reset --hard — discards working-tree and index changes
• git checkout -- . / git restore . — discards unstaged changes
• git branch -D — force-deletes a possibly-unmerged branch
• git push --force — use --force-with-lease instead

Backup before cleanup

Before removing a dirty worktree or running any --force/reset, preserve the work first:

git -C <worktree> stash push -u -m "pre-cleanup"        # quickest, reversible
# or capture a patch you can re-apply later:
git -C <worktree> diff HEAD > /tmp/wt-<task-id>.patch

Only then git worktree remove --force. A 10-second backup beats unrecoverable loss.

The quieter danger: committed-but-never-pushed commits need no --force at all. A plain git worktree remove succeeds fine on a clean working tree — but "clean" only means no uncommitted changes, not that the branch's commits exist anywhere else. If you git add && git commit a doc/note/fix in a worktree and never push it, the worktree directory can be removed with zero warnings; the commits survive on the branch ref for now, but become truly unrecoverable the moment that branch is later deleted (e.g. a routine "clean up merged branches" pass). Run npm run worktree:pre-delete before removing any worktree you didn't just finish pushing — it hard-blocks when the current branch has commits origin/<branch> doesn't have.

Leak guard

These must be gitignored so they never show as untracked or get committed (github/ alone is ~1.7 GB of vendored examples):

.claude/worktrees/ · .worktrees/ · github/ · node_modules/

for d in .claude/worktrees .worktrees github node_modules; do
  git check-ignore -q "$d" || echo "$d/" >> .gitignore
done

iPix today: all four are gitignored (.gitignore root). Re-run the loop above after adding any new top-level scratch/vendor dir — it's idempotent, so it's safe to run before every worktree-heavy session.

Worktree count guard

Before adding a new worktree, audit existing ones — this repo has drifted past the ~3–4 cap (13+ seen in Jul 2026 audit):

npm run worktree:audit              # markdown inventory + health score
npm run worktree:audit -- --write    # refresh docs/development/worktree-tracker.md
git worktree list | wc -l

If it's high, run the weekly tidy ritual first (prune stale metadata, delete branches already merged into origin/main) rather than adding another on top of the pile. A worktree for a task that's already merged or abandoned is pure confusion risk for the next session that runs git worktree list.

Nested worktree guard

Never create a worktree inside the repo or inside another worktree — that nests checkouts and corrupts git status. Before any git worktree add:

• Run Step 0 detection. If GIT_DIR != GIT_COMMON, you're already in a linked worktree — don't nest another; return to the main worktree first.
• Target path must be a sibling (../wt-ipi-…) or under .claude/worktrees/ — never a subdirectory of the current repo.

Decision: how to create the worktree

Try these in order — prefer the harness's native mechanism over raw git. Using git worktree add when a native tool exists creates phantom state the harness can't track or clean up.

1. Already isolated? Detect first (see Step 0). If yes, don't create another.
2. Claude Code native — the EnterWorktree tool, the --worktree/-w CLI flag, or a --worktree/--isolation worktree option on the agent/task tool. This handles placement, branch creation, env copying, and cleanup automatically. Use it.
3. Raw git worktree add — only when no native mechanism is available (plain shell, CI, non-Claude-Code context). See references/git-commands.md.

Step 0: Detect existing isolation (run before creating anything)

GIT_DIR=$(cd "$(git rev-parse --git-dir)" 2>/dev/null && pwd -P)
GIT_COMMON=$(cd "$(git rev-parse --git-common-dir)" 2>/dev/null && pwd -P)
git rev-parse --show-superproject-working-tree 2>/dev/null   # non-empty ⇒ submodule, NOT a worktree

• GIT_DIR != GIT_COMMON and not a submodule → you are already in a linked worktree. Skip creation; go straight to setup. Report: "Already in an isolated worktree at <path> on <branch>."
• GIT_DIR == GIT_COMMON (or in a submodule) → normal checkout. If the user hasn't already expressed a preference, ask before creating one: "Set up an isolated worktree so your current branch stays untouched?" Honor any standing preference without re-asking.

Claude Code native worktrees

The fastest path. Default placement is .claude/worktrees/<name>/ at the repo root, on a new branch worktree-<name>, branched from origin/HEAD (a clean tree matching the remote; falls back to local HEAD if no remote).

claude --worktree feature-auth      # create + start a session in an isolated worktree
claude -w bugfix-123                 # short flag; run in a second terminal for a parallel session
claude --worktree                    # auto-named, e.g. bright-running-fox
claude --worktree "#1234"            # branch from PR #1234 → .claude/worktrees/pr-1234

• In-session: ask Claude to "work in a worktree" and it uses the EnterWorktree tool. It can hop to another worktree under .claude/worktrees/ by calling EnterWorktree with that path; the previous one stays on disk.
• First-time trust: run plain claude once in the directory to accept the trust dialog before --worktree works interactively (-p runs skip this).
• Always add .claude/worktrees/ to .gitignore so worktree contents don't show as untracked in the main checkout.
• Base branch: set worktree.baseRef: "head" in settings to branch from local HEAD (carries unpushed commits) instead of the clean default "fresh".

Copy gitignored files (.env, secrets) — .worktreeinclude

A worktree is a fresh checkout, so untracked files like .env are not present. Add a .worktreeinclude (gitignore syntax) at the project root; matching files that are also gitignored get copied into every new worktree (tracked files are never duplicated):

.env
.env.local
config/secrets.json

Applies to --worktree, subagent worktrees, and desktop parallel sessions. (Not processed when a custom WorktreeCreate hook replaces git behavior — copy configs inside the hook instead.)

Isolate subagents/parallel agents

Give each parallel agent its own worktree so concurrent edits don't conflict: ask Claude to "use worktrees for your agents", or set isolation: worktree in a custom subagent's frontmatter. Each gets a temporary worktree, auto-removed when the agent finishes with no changes. While an agent runs, Claude git worktree locks its worktree so cleanup can't remove it mid-run.

After creation: make the worktree usable

A fresh worktree has the code but none of the environment. Initialize it:

1. Dependencies — install per worktree (they don't share node_modules/.venv):

   [ -f package.json ] && npm install
   [ -f Cargo.toml ]   && cargo build
   [ -f go.mod ]       && go mod download
   [ -f requirements.txt ] && pip install -r requirements.txt
   [ -f pyproject.toml ]   && poetry install
   

2. Untracked config — if not using .worktreeinclude, copy needed .env/secret files in by hand.
3. Port conflicts — parallel worktrees can't all bind the same dev port. Give each a distinct port (e.g. one runs the app on 3002, the parallel one on 3003) or only run one dev server at a time. This is the most common "why is it broken" surprise.
4. Baseline check — run the test/build command once so you can tell new breakage from pre-existing. If it fails, report and ask before continuing rather than chasing a bug you didn't introduce.

Cleanup

Never rm -rf a worktree — that orphans metadata in .git/worktrees/. Use git (or let the native session do it).

• Native sessions: on exit, a worktree with no uncommitted changes, untracked files, or new commits is removed automatically (named sessions prompt instead). A dirty worktree prompts keep-or-remove. -p runs don't auto-clean — remove manually.
• Manual:

  git worktree list                 # see all worktrees + their branches
  git worktree remove <path>        # clean tree required
  git worktree remove --force <path> # discards uncommitted changes
  git worktree prune                # clear stale metadata after a manual delete
  

• Backup first if the worktree is dirty — see Backup before cleanup. Never --force without it.
• Pre-delete gate — npm run worktree:pre-delete (blocks if the branch has commits origin/<branch> doesn't have; see Backup before cleanup).
• Weekly tidy ritual (prune stale branches + merged worktrees) → references/ipix-ops.md#weekly-tidy-ritual.

Quick reference

Task	Command
iPix: add worktree (preferred)	npm run worktree:add -- IPI-286 route-aware-sections
iPix: audit inventory	npm run worktree:audit · -- --write updates tracker
iPix: start-work gate	npm run worktree:health (current worktree) · -- --all (every worktree)
iPix: pre-delete gate	npm run worktree:pre-delete — run before removing a worktree you didn't just push
Native isolated session	claude --worktree <name>
Native, from a PR	claude --worktree "#<n>"
Manual: new branch	git worktree add ../<proj>-<name> -b <branch>
Manual: existing branch	git worktree add ../<proj>-<name> <branch>
Manual: from remote	git worktree add --track -b <branch> ../<p> origin/<branch>
Detached (experiment)	git worktree add --detach ../<proj>-exp <commit>
List	git worktree list
Remove	git worktree remove <path> (--force if dirty)
Prune stale	git worktree prune
Repair after manual move	git worktree repair

Full command set, locking, and troubleshooting → references/git-commands.md. Comparing files/commits and selectively merging between worktrees → references/compare-merge.md. iPix command playbooks (forensic audit, production SHA check, PR splitting, weekly tidy) → references/ipix-ops.md.

Best practices for parallel work

Practice	Why
One worktree per task; cap active ones at ~3–4	More directories ≠ more output; coordination cost grows fast
Name by purpose (-review, -hotfix), not ticket noise	project-review reads clearer than project-pr-123
Native tool over raw git when available	Avoids phantom state the harness can't clean up
Distinct dev port per running worktree	Prevents silent "address in use" failures
Commit or stash before git worktree remove	remove without --force refuses; --force discards work
/clear when switching contexts in a long session	Keeps one task's context from polluting another

Common mistakes

Mistake	Fix
rm -rf to delete a worktree	git worktree remove, then git worktree prune
git worktree add despite a native tool	Use the native mechanism (Step in Decision)
Creating a nested worktree inside another	Run Step 0 detection first
Worktree dir tracked by git	Add .claude/worktrees/ (or your path) to .gitignore
Same dev port in two worktrees	Assign distinct ports
"Branch already checked out" error	A branch lives in one worktree only — git worktree list to find it
Forgetting deps/env in the new worktree	Install deps + copy .env (or use .worktreeinclude)

Non-git VCS

For SVN/Perforce/Mercurial, configure WorktreeCreate and WorktreeRemove hooks to supply custom create/cleanup logic (the hook replaces git behavior, so .worktreeinclude is skipped — copy configs in the hook). See the Claude Code hooks reference.