"Spin up 3-5 git worktrees at once, each running its own Codex session in parallel. It's the single biggest productivity unlock." -- Boris Cherny (Claude Code creator)

Git worktrees let you have multiple working directories from the same repo:

Each worktree = separate feature/branch
Each worktree = separate Codex session
Work on 3-5 features simultaneously
No branch switching, no context loss

Usage

/create-worktree <branch-name> [base-branch]

Examples:

/create-worktree feature-auth          # Create from current branch
/create-worktree feature-auth main     # Create from main
/create-worktree bugfix-login develop  # Create from develop

What This Does

Step 1: Create Worktree Directory

# Worktrees live in ../worktrees/
REPO_NAME=$(basename $(git rev-parse --show-toplevel))
WORKTREE_DIR="../worktrees/${REPO_NAME}-${BRANCH_NAME}"

# Create worktree
git worktree add "$WORKTREE_DIR" -b "$BRANCH_NAME" "$BASE_BRANCH"

Step 2: Initialize Automation

cd "$WORKTREE_DIR"

# Copy .codex structure from main worktree
cp -r /path/to/main/.codex .codex/

# Initialize fresh PR counter (managed by post-merge hook)
# In worktrees, git-common-dir points to the main repo's .git dir,
# so the counter is shared across all worktrees automatically.
COUNTER_FILE="$(git rev-parse --git-common-dir)/hooks-pr-counter"
cat "$COUNTER_FILE" 2>/dev/null || echo "0" > "$COUNTER_FILE"

# Copy CODEX.md
cp /path/to/main/CODEX.md ./

Step 3: Launch Codex Session

# Open new terminal tab/window
# Name it after the branch
# cd to worktree directory
# Launch Codex

# Provide instructions:
echo "✅ Worktree created: $WORKTREE_DIR"
echo ""
echo "Next steps:"
echo "1. Open new terminal tab"
echo "2. cd $WORKTREE_DIR"
echo "3. Run: codex"
echo ""
echo "You can now work on $BRANCH_NAME in parallel!"
echo "(CODEX.md will be auto-loaded in the worktree)"

Directory Structure

After creating worktrees:

your-repo/                    ← Main worktree
├── .git/
│   └── hooks-pr-counter      (PR counter -- shared by all worktrees)
├── .codex/
└── [code]

worktrees/
├── your-repo-feature-auth/   ← Worktree 1
│   ├── .codex/
│   └── [code on feature-auth branch]
├── your-repo-feature-ui/     ← Worktree 2
│   ├── .codex/
│   └── [code on feature-ui branch]
└── your-repo-bugfix-login/   ← Worktree 3
    ├── .codex/
    └── [code on bugfix-login branch]

Workflow: Parallel Development

Terminal Setup

Tab 1: Main (main branch)

~/projects/your-repo
Branch: main
Codex: Coordinating, reviewing

Tab 2: Feature Auth (feature-auth branch)

~/projects/worktrees/your-repo-feature-auth
Branch: feature-auth
Codex: Building auth system

Tab 3: Feature UI (feature-ui branch)

~/projects/worktrees/your-repo-feature-ui
Branch: feature-ui
Codex: Designing new UI

Tab 4: Bugfix (bugfix-login branch)

~/projects/worktrees/your-repo-bugfix-login
Branch: bugfix-login
Codex: Fixing login bug

Parallel Work Example

# Morning: Spin up 3 worktrees
/create-worktree feature-auth
/create-worktree feature-ui
/create-worktree bugfix-login

# Each worktree gets own Codex session
# All work in parallel

# Feature Auth Codex: Implementing OAuth
# Feature UI Codex: Building new dashboard
# Bugfix Codex: Fixing login race condition

# All independent, no context switching!

PR Counter Sharing

All worktrees share a single PR counter because git rev-parse --git-common-dir resolves to the main repo's .git directory regardless of which worktree you are in. The counter file is $(git rev-parse --git-common-dir)/hooks-pr-counter.

# All worktrees read/write the same counter:
COUNTER_FILE="$(git rev-parse --git-common-dir)/hooks-pr-counter"
cat "$COUNTER_FILE"  # Same value from any worktree

This means the assessment waterfall triggers based on total PRs merged across all worktrees, not per-worktree -- which is the desired behavior since assessments cover the whole repo.

Benefits

✅ 3-5x productivity - Work on multiple features simultaneously ✅ No context switching - Each feature has dedicated environment ✅ No branch conflicts - Separate working directories ✅ Independent Codex sessions - Each with own context ✅ Parallel PRs - Submit multiple PRs without blocking

Best Practices

1. Name Terminal Tabs

# Tab names:
"Main"
"Auth Feature"
"UI Redesign"
"Login Fix"

2. Color-Code Tabs

Use terminal color settings to visually distinguish worktrees

3. Use /statusline

# In each worktree, show branch name
/statusline set-format "{{branch}} | {{context}}%"

4. Limit Active Worktrees

Don't exceed 5 active worktrees
Codex team uses 3-5
More = harder to manage

5. Clean Up When Done

# After merging PR, remove worktree
/cleanup-worktrees

Advanced: Tmux Setup

For tmux users:

# Create tmux session per worktree
tmux new-session -s "auth-feature" -c "$WORKTREE_DIR"

# Switch between sessions
tmux attach -t "auth-feature"
tmux attach -t "ui-feature"

Troubleshooting

Worktree Creation Fails

# Check if branch already exists
git branch -a | grep feature-name

# If exists, use different name or checkout existing
git worktree add ../worktrees/repo-feature -b feature-v2

Can't Delete Worktree

# Remove worktree properly
git worktree remove ../worktrees/repo-feature

# If locked, force remove
git worktree remove --force ../worktrees/repo-feature

Shared .git Directory

All worktrees share .git directory:

Commits in any worktree are visible in all
Fetch/pull in one affects all
Be mindful of this shared state

Related Commands

cd ../worktrees/repo-<branch> - Switch between worktrees (manual cd)
/list-worktrees - See all active worktrees
/cleanup-worktrees - Remove merged/abandoned worktrees

Example Session

# Monday morning: Three features to build
/create-worktree feature-payment-gateway main
/create-worktree feature-notification-system main
/create-worktree feature-user-settings main

# Open 3 terminal tabs, start 3 Codex sessions

# Tab 1: Payment Gateway
cd ../worktrees/repo-feature-payment-gateway
codex
# CODEX.md auto-loaded
# "Build Stripe integration"

# Tab 2: Notifications
cd ../worktrees/repo-feature-notification-system
codex
# CODEX.md auto-loaded
# "Build push notification system"

# Tab 3: User Settings
cd ../worktrees/repo-feature-user-settings
codex
# CODEX.md auto-loaded
# "Build user preferences UI"

# All three Codex instances work in parallel
# Submit 3 PRs by end of day
# Main branch never touched