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Copilot CLI

Use GitHub Copilot CLI with agentkernel for isolated code execution.

Quick Start

Copilot CLI supports MCP natively. The agentkernel plugin registers MCP tools that Copilot CLI can call to run code in sandboxes.

# 1. Start agentkernel API server (pick one)
brew services start thrashr888/agentkernel/agentkernel   # runs in background, survives reboots
agentkernel serve                 # or run manually in a terminal

# 2. Install the plugin into your project
agentkernel plugin install copilot

# 3. Launch Copilot CLI — it picks up .mcp.json automatically
github-copilot

MCP Integration

Copilot CLI runs on your machine and calls agentkernel MCP tools to execute code in isolated sandboxes. The plugin merges agentkernel's MCP server into your project's .mcp.json:

agentkernel plugin install copilot

For global installation (available in all projects):

agentkernel plugin install copilot --global

API Key

Copilot CLI requires a GitHub token. Get one from github.com/settings/tokens.

Pass the token when running commands:

# Interactive session
agentkernel attach copilot-dev -e GITHUB_TOKEN=$GITHUB_TOKEN

# One-off command
agentkernel exec copilot-dev -e GITHUB_TOKEN=$GITHUB_TOKEN -- \
  github-copilot "Explain this code"

Sandbox-Based Workflow

You can also run Copilot CLI itself inside an isolated sandbox container:

# Create sandbox with Copilot CLI pre-installed
agentkernel sandbox create copilot-dev --config examples/agents/copilot/agentkernel.toml

# Start the sandbox
agentkernel sandbox start copilot-dev

# Run Copilot CLI with your token
agentkernel attach copilot-dev -e GITHUB_TOKEN=$GITHUB_TOKEN

# Inside the sandbox:
github-copilot

Configuration

Example config at examples/agents/copilot/agentkernel.toml:

[sandbox]
name = "copilot-sandbox"

[build]
dockerfile = "Dockerfile"

[agent]
preferred = "copilot"
compatibility_mode = "native"

[resources]
vcpus = 2
memory_mb = 1024

[security]
profile = "moderate"
network = true      # Copilot CLI needs network for GitHub API
mount_cwd = true    # Mount project directory

Environment Variables

Variable Default Description
AGENTKERNEL_BASE_URL http://localhost:18888 agentkernel API endpoint
AGENTKERNEL_API_KEY - Optional Bearer token for API auth
GITHUB_TOKEN - Required by Copilot CLI for authentication

What's Included

The sandbox image includes:

  • Node.js 22 — Runtime for Copilot CLI
  • Copilot CLI — @githubnext/github-copilot-cli
  • Git — Version control
  • Python 3 — For Python projects
  • ripgrep — Fast code search
  • fd — Fast file finder
  • jq — JSON processing

Customizing

Create a custom Dockerfile based on the example:

FROM node:22-alpine

# Base tools
RUN apk add --no-cache git bash python3 ripgrep fd jq

# Copilot CLI
RUN npm install -g @githubnext/github-copilot-cli

# Your additions
RUN apk add --no-cache rust cargo

# Setup
WORKDIR /workspace
USER developer