Multi-Copilot

Infrastructure for running multiple parallel GitHub Copilot CLI sessions using git worktrees and devcontainers.

Inspired by Jesse Vincent's workflow.

Overview

This repository provides reusable infrastructure (Windows host + PowerShell) that enables:

• Parallel development: Work on multiple branches simultaneously, each in its own container
• Isolated environments: Each worktree gets its own devcontainer with isolated state
• Easy setup: PowerShell scripts automate worktree creation and container management
• Project-agnostic: Copy these files to any project to enable multi-copilot workflows

Quick Start

1. Copy to Your Project

Copy the following to your project:

• .devcontainer/ - Devcontainer configuration
• scripts/ - Worktree management scripts
• .gitattributes - Ensures shell scripts have correct line endings

2. Customize the Devcontainer

Edit .devcontainer/Dockerfile to add your project's dependencies (languages, tools, etc.).

Edit .devcontainer/devcontainer.json to:

• Change the name to your project name
• Update VS Code extensions for your tech stack

3. Set Environment Variables

Set these on your Windows host:

# Required: GitHub authentication
$env:GH_TOKEN = (gh auth token)

# Optional: Git identity
$env:GIT_USER_NAME = "Your Name"
$env:GIT_USER_EMAIL = "your.email@example.com"

# Optional: SSH commit signing
$env:GIT_SIGNING_KEY = "id_ed25519"  # or your key name

4. Start a Worktree Session

Option A: PowerShell scripts (for parallel Copilot CLI sessions)

.\scripts\worktree-up.ps1 feature-branch

Option B: VS Code (for single-session development)

Open the folder in VS Code with the Dev Containers extension installed. VS Code will prompt to reopen in container.

This will:

1. Create a git worktree at .worktrees/feature-branch/
2. Start a devcontainer for that worktree
3. Configure Copilot CLI
4. Launch Copilot in the container

5. Verify Setup

Inside the container, run:

bash scripts/smoke-test.sh

6. Check Status

.\scripts\worktree-status.ps1

7. Clean Up

# Remove a specific worktree and its container
.\scripts\worktree-down.ps1 feature-branch

# Clean up orphaned containers and project volumes (prompts first)
.\scripts\worktree-cleanup.ps1

How It Works

Git Worktrees

Git worktrees allow multiple working directories linked to the same repository. Each worktree can be on a different branch, enabling parallel development without stashing or committing.

Worktrees are created in .worktrees/ inside your repo (gitignored).

Branch Switching: You can switch branches inside a worktree with git checkout. The scripts identify worktrees by directory name (not current branch), so worktree-up and worktree-down work correctly even after switching branches.

Devcontainers

Each worktree gets its own Docker container with:

• Isolated filesystem
• Pre-configured Copilot CLI (yolo mode by default)
• Git authentication via GH_TOKEN

Path Translation

The tricky part is that git worktrees on Windows use host paths, but inside containers we need container paths. The scripts handle this by:

1. Mounting the main .git directory at a known location
2. Rewriting worktree .git files to use container paths
3. Restoring host paths when exiting

File Structure

.devcontainer/
├── devcontainer.json      # Container configuration
├── Dockerfile             # Build dependencies (customize this)
├── copilot-config.json    # Copilot CLI settings (yolo mode)
├── mcp-config.json        # MCP server configuration
└── setup-git-auth.sh      # Configure git authentication

scripts/
├── worktree-up.ps1        # Create worktree + start container
├── worktree-down.ps1      # Remove worktree + stop container
├── worktree-status.ps1    # Show all worktrees and container status
├── worktree-cleanup.ps1   # Clean up orphaned containers
├── smoke-test.sh          # Verify devcontainer setup
└── README.md              # Script documentation

Customization

Adding MCP Servers

Edit .devcontainer/mcp-config.json:

{
  "mcpServers": {
    "your-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "your-mcp-server"],
      "env": {
        "API_TOKEN": "${YOUR_API_TOKEN}"
      }
    }
  }
}

Then add the env var to remoteEnv in devcontainer.json.

Adding Environment Variables

Add to remoteEnv in devcontainer.json:

"remoteEnv": {
  "MY_TOKEN": "${localEnv:MY_TOKEN}"
}

Requirements

• Windows with PowerShell 5.1+ (scripts are PowerShell/Windows-focused)
• Git with worktree support
• Docker Desktop
• Node.js (for devcontainer CLI)
• GitHub CLI (gh) for authentication

License

Copyright 2026 James Casey
SPDX-License-Identifier: Apache-2.0