Git Worktree Manager

Tier: POWERFUL Category: Engineering / Developer Tooling Maintainer: Claude Skills Team

Overview

Manage parallel development workflows using Git worktrees with deterministic naming, automatic port allocation, environment file synchronization, dependency installation, and cleanup automation. Optimized for multi-agent workflows where each agent or terminal session owns an isolated worktree with its own ports, environment, and running services.

Keywords

git worktree, parallel development, branch isolation, port allocation, multi-agent development, worktree cleanup, Docker Compose worktree, concurrent branches

Core Capabilities

1. Worktree Lifecycle Management

Create worktrees from new or existing branches with deterministic naming
Copy .env files from main repo to new worktrees
Install dependencies based on lockfile detection
List all worktrees with status (clean/dirty, ahead/behind)
Safe cleanup with uncommitted change detection

2. Port Allocation

Deterministic port assignment per worktree (base + index * stride)
Collision detection against running processes
Persistent port map in
```
.worktree-ports.json
```
Docker Compose override generation for per-worktree ports

3. Multi-Agent Isolation

One branch per worktree, one agent per worktree
No shared state between agent workspaces
Conflict-free parallel execution
Task ID mapping for traceability

4. Cleanup Automation

Stale worktree detection by age
Merged branch detection for safe removal
Dirty state warnings before deletion
Bulk cleanup with safety confirmations

When to Use

You need 2+ concurrent branches open with running dev servers
You want isolated environments for feature work, hotfixes, and PR review
Multiple AI agents need separate workspaces that do not interfere
Your current branch is blocked but a hotfix is urgent
You want automated cleanup instead of manual
```
rm -rf
```
operations

Quick Start

Create a Worktree

bash

# Create worktree for a new feature branch
git worktree add ../wt-auth -b feature/new-auth main

# Create worktree from an existing branch
git worktree add ../wt-hotfix hotfix/fix-login

# Create worktree in a dedicated directory
git worktree add ~/worktrees/myapp-auth -b feature/auth origin/main

List All Worktrees

bash

git worktree list
# Output:
# /Users/dev/myapp              abc1234 [main]
# /Users/dev/wt-auth            def5678 [feature/new-auth]
# /Users/dev/wt-hotfix          ghi9012 [hotfix/fix-login]

Remove a Worktree

bash

# Safe removal (fails if there are uncommitted changes)
git worktree remove ../wt-auth

# Force removal (discards uncommitted changes)
git worktree remove --force ../wt-auth

# Prune stale metadata
git worktree prune

Port Allocation Strategy

Deterministic Port Assignment

Each worktree gets a block of ports based on its index:

Worktree Index    App Port    DB Port    Redis Port    API Port
────────────────────────────────────────────────────────────────
0 (main)          3000        5432       6379          8000
1 (wt-auth)       3010        5442       6389          8010
2 (wt-hotfix)     3020        5452       6399          8020
3 (wt-feature)    3030        5462       6409          8030

Formula:

port = base_port + (worktree_index * stride)

Default stride: 10

Port Map File

Store the allocation in

.worktree-ports.json

at the worktree root:

json

{
  "worktree": "wt-auth",
  "branch": "feature/new-auth",
  "index": 1,
  "ports": {
    "app": 3010,
    "database": 5442,
    "redis": 6389,
    "api": 8010
  },
  "created": "2026-03-09T10:30:00Z"
}

Port Collision Detection

bash

# Check if a port is already in use
check_port() {
  local port=$1
  if lsof -i :"$port" > /dev/null 2>&1; then
    echo "PORT $port is BUSY"
    return 1
  else
    echo "PORT $port is FREE"
    return 0
  fi
}

# Check all ports for a worktree
for port in 3010 5442 6389 8010; do
  check_port $port
done

Full Worktree Setup Script

bash

#!/bin/bash
# setup-worktree.sh — Create a fully prepared worktree
set -euo pipefail

BRANCH="${1:?Usage: setup-worktree.sh <branch-name> [base-branch]}"
BASE="${2:-main}"
WT_NAME="wt-$(echo "$BRANCH" | sed 's|.*/||' | tr '[:upper:]' '[:lower:]')"
WT_PATH="../$WT_NAME"
MAIN_REPO="$(git rev-parse --show-toplevel)"

echo "Creating worktree: $WT_PATH from $BASE..."

# 1. Create worktree
if git rev-parse --verify "$BRANCH" > /dev/null 2>&1; then
  git worktree add "$WT_PATH" "$BRANCH"
else
  git worktree add "$WT_PATH" -b "$BRANCH" "$BASE"
fi

# 2. Copy environment files
for envfile in .env .env.local .env.development; do
  if [ -f "$MAIN_REPO/$envfile" ]; then
    cp "$MAIN_REPO/$envfile" "$WT_PATH/$envfile"
    echo "Copied $envfile"
  fi
done

# 3. Allocate ports
WT_INDEX=$(git worktree list | grep -n "$WT_PATH" | cut -d: -f1)
WT_INDEX=$((WT_INDEX - 1))
STRIDE=10

cat > "$WT_PATH/.worktree-ports.json" << EOF
{
  "worktree": "$WT_NAME",
  "branch": "$BRANCH",
  "index": $WT_INDEX,
  "ports": {
    "app": $((3000 + WT_INDEX * STRIDE)),
    "database": $((5432 + WT_INDEX * STRIDE)),
    "redis": $((6379 + WT_INDEX * STRIDE)),
    "api": $((8000 + WT_INDEX * STRIDE))
  }
}
EOF
echo "Ports allocated (index $WT_INDEX)"

# 4. Update .env with allocated ports
if [ -f "$WT_PATH/.env" ]; then
  APP_PORT=$((3000 + WT_INDEX * STRIDE))
  DB_PORT=$((5432 + WT_INDEX * STRIDE))
  sed -i.bak "s/APP_PORT=.*/APP_PORT=$APP_PORT/" "$WT_PATH/.env"
  sed -i.bak "s/:5432/:$DB_PORT/g" "$WT_PATH/.env"
  rm -f "$WT_PATH/.env.bak"
  echo "Updated .env with worktree ports"
fi

# 5. Install dependencies
cd "$WT_PATH"
if [ -f "pnpm-lock.yaml" ]; then
  pnpm install --frozen-lockfile
elif [ -f "package-lock.json" ]; then
  npm ci
elif [ -f "yarn.lock" ]; then
  yarn install --frozen-lockfile
elif [ -f "requirements.txt" ]; then
  pip install -r requirements.txt
elif [ -f "go.mod" ]; then
  go mod download
fi

echo ""
echo "Worktree ready: $WT_PATH"
echo "Branch: $BRANCH"
echo "App port: $((3000 + WT_INDEX * STRIDE))"
echo ""
echo "Next: cd $WT_PATH && pnpm dev"

Docker Compose Per-Worktree

yaml

# docker-compose.worktree.yml — override for worktree-specific ports
# Usage: docker compose -f docker-compose.yml -f docker-compose.worktree.yml up

services:
  postgres:
    ports:
      - "${DB_PORT:-5432}:5432"
    environment:
      POSTGRES_DB: "myapp_${WT_NAME:-main}"

  redis:
    ports:
      - "${REDIS_PORT:-6379}:6379"

  app:
    ports:
      - "${APP_PORT:-3000}:3000"
    environment:
      DATABASE_URL: "postgresql://dev:dev@postgres:5432/myapp_${WT_NAME:-main}"

Launch with worktree-specific ports:

bash

DB_PORT=5442 REDIS_PORT=6389 APP_PORT=3010 WT_NAME=auth \
  docker compose -f docker-compose.yml -f docker-compose.worktree.yml up -d

Cleanup Automation

bash

#!/bin/bash
# cleanup-worktrees.sh — Safe worktree cleanup
set -euo pipefail

STALE_DAYS="${1:-14}"
DRY_RUN="${2:-true}"

echo "Scanning worktrees (stale threshold: ${STALE_DAYS} days)..."
echo ""

git worktree list --porcelain | while read -r line; do
  case "$line" in
    worktree\ *)
      WT_PATH="${line#worktree }"
      ;;
    branch\ *)
      BRANCH="${line#branch refs/heads/}"
      # Skip main worktree
      if [ "$WT_PATH" = "$(git rev-parse --show-toplevel)" ]; then
        continue
      fi

      # Check if branch is merged
      MERGED=""
      if git branch --merged main | grep -q "$BRANCH" 2>/dev/null; then
        MERGED=" [MERGED]"
      fi

      # Check for uncommitted changes
      DIRTY=""
      if [ -d "$WT_PATH" ]; then
        cd "$WT_PATH"
        if [ -n "$(git status --porcelain)" ]; then
          DIRTY=" [DIRTY - has uncommitted changes]"
        fi
        cd - > /dev/null
      fi

      # Check age
      if [ -d "$WT_PATH" ]; then
        AGE_DAYS=$(( ($(date +%s) - $(stat -f %m "$WT_PATH" 2>/dev/null || stat -c %Y "$WT_PATH" 2>/dev/null)) / 86400 ))
        STALE=""
        if [ "$AGE_DAYS" -gt "$STALE_DAYS" ]; then
          STALE=" [STALE: ${AGE_DAYS} days old]"
        fi
      fi

      echo "$WT_PATH ($BRANCH)$MERGED$DIRTY$STALE"

      if [ -n "$MERGED" ] && [ -z "$DIRTY" ] && [ "$DRY_RUN" = "false" ]; then
        echo "  -> Removing merged clean worktree..."
        git worktree remove "$WT_PATH"
      fi
      ;;
  esac
done

echo ""
git worktree prune
echo "Done. Run with 'false' as second arg to actually remove."

Multi-Agent Workflow Pattern

When running multiple AI agents (Claude Code, Cursor, Copilot) on the same repo:

Agent Assignment:
───────────────────────────────────────────────────
Agent 1 (Claude Code)  → wt-feature-auth   (port 3010)
Agent 2 (Cursor)       → wt-feature-billing (port 3020)
Agent 3 (Copilot)      → wt-bugfix-login   (port 3030)
Main repo              → integration (main) (port 3000)
───────────────────────────────────────────────────

Rules:
- Each agent works ONLY in its assigned worktree
- No agent modifies another agent's worktree
- Integration happens via PRs to main, not direct merges
- Port conflicts are impossible due to deterministic allocation

Decision Matrix

Scenario	Action
Need isolated dev server for a feature	Create a new worktree
Quick diff review of a branch	`git diff` in current tree (no worktree needed)
Hotfix while feature branch is dirty	Create dedicated hotfix worktree
Bug triage with reproduction branch	Temporary worktree, cleanup same day
PR review with running code	Worktree at PR branch, run tests
Multiple agents on same repo	One worktree per agent

Validation Checklist

After creating a worktree, verify:

```
git worktree list
```
shows the expected path and branch
```
.worktree-ports.json
```
exists with unique port assignments
```
.env
```
files are present and contain worktree-specific ports
```
pnpm install
```
(or equivalent) completed without errors
Dev server starts on the allocated port
Database connects on the allocated DB port
No port conflicts with other worktrees or services

Common Pitfalls

Creating worktrees inside the main repo directory — always use
```
../wt-name
```
to keep them alongside
Reusing localhost:3000 across all branches — causes port conflicts; use deterministic allocation
Sharing one DATABASE_URL across worktrees — each needs its own database or schema
Removing a worktree with uncommitted changes — always check dirty state before removal
Forgetting to prune after branch deletion — run
```
git worktree prune
```
to clean metadata
Not updating .env ports after worktree creation — the setup script should handle this automatically

Best Practices

One branch per worktree, one agent per worktree — never share
Keep worktrees short-lived — remove after the branch is merged
Deterministic naming — use
```
wt-<topic>
```
pattern for easy identification
Persist port mappings — store in
```
.worktree-ports.json
```
, not in memory
Run cleanup weekly — scan for stale and merged-branch worktrees
Include worktree path in terminal title — prevents wrong-window commits
Never force-remove dirty worktrees — unless changes are intentionally discarded

Troubleshooting

Problem	Cause	Solution
`fatal: '<path>' is already checked out`	Branch is already active in another worktree	Use `git worktree list` to find where the branch is checked out, then switch to a different branch or remove the existing worktree first
Port conflict despite deterministic allocation	A non-worktree process is occupying the assigned port	Run `lsof -i :<port>` to identify the process, terminate it or adjust the stride/base in the port allocation formula
`.env` file missing after worktree creation	Setup script was not run or `.env` does not exist in the main repo	Copy `.env` manually from the main repo root, or re-run `setup-worktree.sh` which handles env file copying
`git worktree prune` reports nothing but stale paths remain	Worktree directory was deleted manually without `git worktree remove`	Run `git worktree prune` to clean orphaned metadata, then verify with `git worktree list`
Dependencies fail to install in new worktree	Lockfile references a private registry or cache not available in the worktree path	Ensure `.npmrc` , `.yarnrc.yml` , or pip config files are copied alongside `.env` during setup
Docker Compose services start on wrong ports	The `docker-compose.worktree.yml` override was not included in the compose command	Always pass both files: `docker compose -f docker-compose.yml -f docker-compose.worktree.yml up`
Worktree shows as dirty immediately after creation	Untracked files from `.env` copy or generated `.worktree-ports.json`	Add `.worktree-ports.json` and copied env files to `.gitignore` in the project

Success Criteria

Zero port conflicts across all active worktrees measured by
```
lsof
```
checks returning no collisions after setup
Worktree creation under 60 seconds including dependency installation for projects with warm package caches
100% env parity between main repo and worktrees verified by diffing
```
.env
```
keys (values may differ for ports)
Stale worktree count stays at zero when cleanup automation runs on a weekly schedule with a 14-day threshold
No cross-worktree interference validated by running concurrent dev servers in 3+ worktrees simultaneously without failures
Branch-to-worktree traceability maintained via
```
.worktree-ports.json
```
present in every active worktree with correct metadata
Cleanup safety rate of 100% meaning no worktree with uncommitted changes is ever removed without explicit
```
--force
```
confirmation

Scope & Limitations

This skill covers:

Git worktree lifecycle: creation, listing, status inspection, and removal
Deterministic port allocation and collision avoidance for parallel dev servers
Environment file synchronization and Docker Compose override patterns
Multi-agent workspace isolation strategies and cleanup automation

This skill does NOT cover:

Git branching strategies or merge conflict resolution (see
```
pr-review-expert
```
and
```
release-manager
```
)
Secret rotation, vault integration, or credential management (see
```
env-secrets-manager
```
)
CI/CD pipeline configuration or automated test orchestration (see
```
ci-cd-pipeline-builder
```
)
Monorepo package management, workspace linking, or cross-package dependency resolution (see
```
monorepo-navigator
```
)

Integration Points

Skill	Integration	Data Flow
`env-secrets-manager`	Worktree setup copies `.env` files that contain secrets managed by this skill	`.env` files flow from main repo to each worktree; secret references remain consistent across all copies
`ci-cd-pipeline-builder`	CI pipelines can spin up worktrees for parallel test matrix execution	Pipeline config triggers `setup-worktree.sh` per matrix job; port allocation prevents service collisions
`release-manager`	Release branches get dedicated worktrees for stabilization while feature work continues	Release worktree is created from the release branch; merged status drives cleanup automation
`monorepo-navigator`	In monorepo setups, worktrees must respect package boundaries and shared dependencies	Worktree creation inherits the monorepo root lockfile; package-level dev servers use allocated port blocks
`pr-review-expert`	PR reviews can be performed in isolated worktrees with running code for manual validation	Reviewer creates a worktree at the PR branch, runs the dev server on allocated ports, and removes after review
`tech-debt-tracker`	Stale worktrees and abandoned branches surface as tech debt indicators	Cleanup script output feeds into debt tracking; worktree age and merge status inform priority scores

git-worktree-manager

NPX Install

Tags

SKILL.md Content

Git Worktree Manager

Overview

Keywords

Core Capabilities

1. Worktree Lifecycle Management

2. Port Allocation

3. Multi-Agent Isolation

4. Cleanup Automation

When to Use

Quick Start

Create a Worktree

List All Worktrees

Remove a Worktree

Port Allocation Strategy

Deterministic Port Assignment

Port Map File

Port Collision Detection

Full Worktree Setup Script

Docker Compose Per-Worktree

Cleanup Automation

Multi-Agent Workflow Pattern

Decision Matrix

Validation Checklist

Common Pitfalls

Best Practices

Troubleshooting

Success Criteria

Scope & Limitations

Integration Points