Copilot CLI

GitHub Copilot CLI brings GitHub's Copilot agent directly to the command line, with native ACP support for seamless integration with Agent Integration Kit.

Prerequisites

A GitHub Copilot subscription (Individual, Business, or Enterprise)
Node.js 22+ (if installing via npm)

Step 1: Install Copilot CLI

npm install -g @github/copilot

brew install copilot-cli

winget install GitHub.Copilot

curl -fsSL https://gh.io/copilot-install | bash

Verify installation: copilot --version

Step 2: Authenticate

After installing, you must log in to your GitHub account. Open a terminal and run:

copilot login

Follow the on-screen instructions to authenticate with your GitHub account.

You must run copilot login at least once before using it in the plugin. The plugin spawns Copilot non-interactively, so it cannot handle the login prompt.

Step 3: Use in Unreal Editor

Open the Agent Chat window in Unreal Editor
Select Copilot CLI from the agent dropdown
Start chatting — the plugin will automatically spawn Copilot in ACP mode with access to all Unreal Editor tools

The plugin automatically writes the MCP server configuration to ~/.copilot/mcp-config.json on first launch, giving Copilot access to all Unreal Editor tools.

If automatic configuration doesn't work, you can manually add the MCP server. Open Copilot CLI in a terminal and run:

/mcp add

Then configure with these values:

Name: unreal-editor
Type: http
URL: http://localhost:9315/mcp
Tools: *

Replace 9315 with the actual MCP server port shown in the Output Log.

Plugin Settings

Setting	Description
Copilot CLI	Path to `copilot` executable (leave blank if in PATH)
Node.js Path (Windows)	Path to `node.exe` — required on Windows if Node.js is not in PATH (npm installs only)

Settings are in Project Settings > Plugins > Agent Integration Kit > Path Overrides.

Features

GitHub Copilot's agentic capabilities inside Unreal Editor
Native ACP support — no separate adapter needed
Streaming responses with tool call support
Permission requests for tool execution
Multiple model support

Troubleshooting

Issue	Solution
"Copilot CLI not found"	Run `copilot --version` in terminal. If not found, reinstall or set the full path in settings
"Node.js not found" (Windows)	Set Node.js Path in Project Settings (only applies to npm installs)
Authentication issues	Run `copilot` in terminal and use `/login` to re-authenticate
No response from agent	Check Output Log for pipe errors. Ensure no other process is using the Copilot CLI
Connection timeout	Restart the editor and try again. Verify your Copilot subscription is active