Git Worktrees

Git Worktrees for Concurrent AI Agent Work

One worktree per agent session. Zero merge conflicts. Full isolation.

The Problem

Multiple AI agent sessions working on the same repository cause chaos. Session A is on branch feature/auth. Session B switches to main to check something. Session A's next tool call fails because the branch disappeared. Or worse: Session B force-pushes over Session A's work.

Traditional solutions don't work:

• Separate clones: waste disk space, slow sync
• Branch locking: blocks parallelism
• Careful coordination: requires manual intervention

The insight: Git worktrees provide isolated working directories sharing the same .git repository. Each AI session gets its own worktree. They can't interfere with each other.

The Pattern

Worktree Basics

A worktree is a separate working directory linked to the same Git repository.

Create a worktree:

git worktree add ~/worktrees/feature-auth feature/auth

This creates:

• Working directory at ~/worktrees/feature-auth
• Checked out to branch feature/auth
• Shares .git with main repository
• Independent of other worktrees

List worktrees:

git worktree list

Remove a worktree:

git worktree remove ~/worktrees/feature-auth

One Worktree Per AI Session

Pattern: Isolated Feature Development

Session A wants to work on authentication:

cd ~/code/myapp
git worktree add ~/.claude/worktrees/auth feature/auth
cd ~/.claude/worktrees/auth
# AI agent works here, isolated from other sessions

Session B wants to work on payments:

cd ~/code/myapp
git worktree add ~/.claude/worktrees/payments feature/payments
cd ~/.claude/worktrees/payments
# AI agent works here, completely independent

Benefits:

• Sessions can't switch each other's branches
• No conflicts from simultaneous edits
• No force-push overwrites
• Clean separation of concerns

Worktree Lifecycle

1. Create worktree for new feature:

# From main repository
git worktree add ~/.claude/worktrees/feature-name -b feature/name

2. AI agent works in worktree:

cd ~/.claude/worktrees/feature-name
# Agent makes changes, commits, pushes
git add .
git commit -m "feat: implement feature"
git push origin feature/name

3. Create PR, merge, cleanup:

# After PR is merged
git worktree remove ~/.claude/worktrees/feature-name
git branch -d feature/name

Detached HEAD for Safety

Use detached HEAD when multiple sessions might access the same branch.

Problem:

# Session A
git worktree add ~/.claude/worktrees/review-pr-123 feature/auth

# Session B tries same branch
git worktree add ~/.claude/worktrees/session-b feature/auth
# ERROR: 'feature/auth' is already checked out at '~/.claude/worktrees/review-pr-123'

Solution: Detached HEAD

# Session A
git worktree add ~/.claude/worktrees/review-pr-123 feature/auth

# Session B uses detached HEAD
git worktree add ~/.claude/worktrees/session-b --detach feature/auth
cd ~/.claude/worktrees/session-b
# Make changes
git add .
git commit -m "fix: resolve issue"
git push origin HEAD:feature/auth-session-b

Worktree Location Strategy

Never use /tmp/:

# BAD: Other sessions run cleanup scripts
git worktree add /tmp/feature-auth feature/auth
# Session B runs: rm -rf /tmp/worktree-*
# Session A's work is gone!

Use dedicated worktree directory:

# GOOD: Persistent location
mkdir -p ~/.claude/worktrees
git worktree add ~/.claude/worktrees/feature-auth feature/auth

Naming convention:

~/.claude/worktrees/
  ├── auth-session-1/
  ├── auth-session-2/
  ├── payments-fix/
  └── review-pr-456/

Pattern: ~/.claude/worktrees/<feature>-<session-id>

Integration with AI Tools

Claude Code worktree isolation:

# Session A
claude --worktree ~/.claude/worktrees/feature-a

# Session B (different worktree)
claude --worktree ~/.claude/worktrees/feature-b

Each session works in its own worktree, zero interference.

OpenCode multi-session pattern:

# Terminal 1: Frontend work
cd ~/.claude/worktrees/frontend-dashboard
opencode

# Terminal 2: Backend work
cd ~/.claude/worktrees/backend-api
opencode

# Terminal 3: Bug fix
cd ~/.claude/worktrees/fix-auth-bug
opencode

Three agents, three worktrees, no conflicts.

Worktree Cleanup Automation

Manual cleanup:

# After PR merged
git worktree remove ~/.claude/worktrees/feature-name
git branch -d feature/name
git remote prune origin

Automated cleanup script:

#!/bin/bash
# cleanup-worktrees.sh

WORKTREE_DIR="$HOME/.claude/worktrees"

# Find all worktrees
git worktree list --porcelain | grep -E '^worktree' | cut -d' ' -f2 | while read -r worktree; do
  if [[ "$worktree" != *"$WORKTREE_DIR"* ]]; then
    continue
  fi

  cd "$worktree" || continue
  branch=$(git rev-parse --abbrev-ref HEAD)

  # Check if branch merged to main
  if git merge-base --is-ancestor HEAD origin/main; then
    echo "Removing merged worktree: $worktree"
    git worktree remove "$worktree"
    git branch -d "$branch" 2>/dev/null
  fi
done

# Prune deleted worktrees
git worktree prune

Add to cron (weekly cleanup):

0 2 * * 0 cd ~/code/myapp && ~/scripts/cleanup-worktrees.sh

Worktree for Code Review

Pattern: Review PR in isolated worktree

# PR #456 needs review
gh pr checkout 456 --worktree ~/.claude/worktrees/review-pr-456

cd ~/.claude/worktrees/review-pr-456

# AI agent reviews code, suggests changes
# Create review comments
gh pr review 456 --comment -b "Suggested changes"

# Cleanup after review
cd ~/code/myapp
git worktree remove ~/.claude/worktrees/review-pr-456

Benefits:

• Don't pollute main working directory
• Can review multiple PRs concurrently
• Easy cleanup after review

Worktree for Hotfixes

Pattern: Emergency fix in production

# Production is broken, need hotfix
git worktree add ~/.claude/worktrees/hotfix-auth --detach production

cd ~/.claude/worktrees/hotfix-auth

# AI agent fixes the bug
git add .
git commit -m "fix: resolve auth crash"
git push origin HEAD:hotfix/auth-crash

# Create PR to production
gh pr create --base production --head hotfix/auth-crash

# After merge, cleanup
cd ~/code/myapp
git worktree remove ~/.claude/worktrees/hotfix-auth

Benefits:

• Don't disrupt ongoing feature work
• Fast context switch to production
• Clean separation from dev branches

Anti-Patterns

1. Shared Branches Between Agents

Bad:

# Session A
cd ~/code/myapp
git checkout feature/auth
# AI works here

# Session B (same repo)
cd ~/code/myapp
git checkout main
# Session A's checkout is now broken!

Why bad:

• Sessions overwrite each other's branch checkouts
• Agent A's next tool call fails (unexpected branch)
• Force-push from one session overwrites the other

Fix:

# Session A
git worktree add ~/.claude/worktrees/session-a feature/auth
cd ~/.claude/worktrees/session-a

# Session B
git worktree add ~/.claude/worktrees/session-b feature/payments
cd ~/.claude/worktrees/session-b

# Fully isolated

2. Using /tmp for Worktrees

Bad:

git worktree add /tmp/feature-auth feature/auth

Why bad:

• Other sessions might run rm -rf /tmp/worktree-*
• System cleanup scripts delete /tmp on reboot
• Work is lost unexpectedly

Fix:

# Use persistent directory
git worktree add ~/.claude/worktrees/feature-auth feature/auth

3. No Cleanup After Completion

Bad:

# Create worktree
git worktree add ~/.claude/worktrees/feature-auth feature/auth

# Finish work, merge PR, forget to cleanup
# Weeks later: dozens of stale worktrees
git worktree list
# ~/.claude/worktrees/feature-auth (merged 3 weeks ago)
# ~/.claude/worktrees/feature-payments (merged 2 weeks ago)
# ~/.claude/worktrees/fix-bug (merged 1 week ago)

Why bad:

• Wasted disk space
• Confusing to know which worktrees are active
• Stale branches not cleaned up

Fix:

# After PR merged
git worktree remove ~/.claude/worktrees/feature-auth
git branch -d feature/auth

# Or use automated cleanup script (see above)

4. Force-Pushing Over Each Other

Bad:

# Session A (worktree A)
git push origin feature/auth

# Session B (worktree B, same branch via --detach)
git push --force origin feature/auth
# Session A's commits are gone!

Why bad:

• Force-push overwrites other session's work
• No warning or conflict resolution
• Data loss

Fix:

# Session A
git push origin feature/auth

# Session B: use different branch
git push origin HEAD:feature/auth-session-b

# Then reconcile via PR

5. Forgetting Which Worktree You're In

Bad:

# In worktree A
cd ~/.claude/worktrees/feature-auth
# ... work ...

# Later, forget which worktree
cd ~/code/myapp
git status
# On branch main (not feature/auth!)
# Make changes to wrong branch

Why bad:

• Changes go to wrong branch
• Confusion about current state
• Hard to track which session did what

Fix:

# Add worktree info to prompt
PS1='[$(basename $(git worktree list | grep $(pwd) | awk "{print \$1}"))] \w $ '

# Or use git status
git worktree list
# /Users/user/code/myapp              abc123 [main]
# /Users/user/.claude/worktrees/auth  def456 [feature/auth]

# Always check before committing
git branch --show-current

6. Not Syncing Worktrees

Bad:

# Session A worktree
cd ~/.claude/worktrees/feature-auth
# Work, commit, push

# Session B worktree (same repo)
cd ~/.claude/worktrees/feature-payments
git status
# Doesn't see Session A's commits to main

Why bad:

• Worktrees share .git but not working directories
• Changes in one worktree don't auto-appear in others
• Can lead to merge conflicts

Fix:

# In each worktree, fetch regularly
git fetch origin

# Or rebase on updated main
git rebase origin/main

7. Creating Worktrees Inside Worktrees

Bad:

cd ~/.claude/worktrees/feature-auth
git worktree add ./nested feature/nested

Why bad:

• Confusing nested structure
• Hard to track and cleanup
• Can cause Git to behave unexpectedly

Fix:

# All worktrees at same level
git worktree add ~/.claude/worktrees/feature-auth feature/auth
git worktree add ~/.claude/worktrees/feature-nested feature/nested

Practical Workflow

Daily Worktree Routine

Morning: Create worktree for today's work

cd ~/code/myapp
git fetch origin
git worktree add ~/.claude/worktrees/feature-dashboard -b feature/dashboard origin/main
cd ~/.claude/worktrees/feature-dashboard

During day: Work in worktree

# AI agent makes changes
git add .
git commit -m "feat: add dashboard component"
git push origin feature/dashboard

Evening: Cleanup if merged

# Check if merged
git log origin/main --oneline | grep "dashboard"

# If merged, cleanup
cd ~/code/myapp
git worktree remove ~/.claude/worktrees/feature-dashboard
git branch -d feature/dashboard

Multi-Agent Workflow

3 agents, 3 worktrees, parallel work:

# Terminal 1: Frontend dashboard
git worktree add ~/.claude/worktrees/frontend-dashboard feature/dashboard
cd ~/.claude/worktrees/frontend-dashboard
claude-agent "Build user dashboard UI"

# Terminal 2: Backend API
git worktree add ~/.claude/worktrees/backend-api feature/api-dashboard
cd ~/.claude/worktrees/backend-api
claude-agent "Build dashboard API endpoints"

# Terminal 3: Tests
git worktree add ~/.claude/worktrees/tests-dashboard feature/test-dashboard
cd ~/.claude/worktrees/tests-dashboard
claude-agent "Write E2E tests for dashboard"

Each agent works independently, no conflicts.

Emergency Hotfix Workflow

Production broken, need immediate fix:

# Don't touch main working directory
git worktree add ~/.claude/worktrees/hotfix-urgent --detach production

cd ~/.claude/worktrees/hotfix-urgent

# Fix the bug
git add .
git commit -m "fix: critical auth bug"
git push origin HEAD:hotfix/auth-urgent

# Create and merge PR
gh pr create --base production --head hotfix/auth-urgent
gh pr merge hotfix/auth-urgent --admin --squash

# Cleanup
cd ~/code/myapp
git worktree remove ~/.claude/worktrees/hotfix-urgent

# Resume normal work in main directory
cd ~/code/myapp
git pull origin main

Worktree Status Script

Track all active worktrees:

#!/bin/bash
# worktree-status.sh

echo "Active worktrees:"
git worktree list --porcelain | awk '
  /^worktree/ { path=$2 }
  /^branch/ { branch=$2; print "  " path " → " branch }
  /^detached/ { print "  " path " → (detached)" }
'

echo ""
echo "Merged and ready for cleanup:"
git worktree list --porcelain | grep -E '^worktree' | cut -d' ' -f2 | while read -r worktree; do
  if [[ "$worktree" == *".claude/worktrees"* ]]; then
    cd "$worktree" || continue
    if git merge-base --is-ancestor HEAD origin/main 2>/dev/null; then
      echo "  $(basename $worktree)"
    fi
  fi
done

Usage:

./worktree-status.sh

# Output:
# Active worktrees:
#   /Users/user/code/myapp → main
#   /Users/user/.claude/worktrees/feature-auth → feature/auth
#   /Users/user/.claude/worktrees/feature-dashboard → feature/dashboard
#
# Merged and ready for cleanup:
#   feature-auth

Gotchas and Edge Cases

1. Can't checkout same branch twice: Use --detach for second checkout
2. Disk space: Each worktree is a full working directory (plan ~500MB per worktree)
3. IDE confusion: Some IDEs don't handle worktrees well (VS Code needs separate windows)
4. Hooks: Pre-commit hooks run independently in each worktree
5. Submodules: Must be initialized separately in each worktree
6. Lock files: package-lock.json, yarn.lock can diverge between worktrees (sync carefully)

Worktrees give AI agents their own playground. No more stepping on each other's toes. One worktree per session, clean isolation, zero conflicts.