Skip to content

Copilot CLI

Wire justpen-browser-mcp into GitHub Copilot CLI.

Prerequisites

  • Copilot CLI installed and authenticated with MCP support enabled
  • justpen-browser-mcp installed and on PATH (see Install)

Registration

Add to ~/.copilot/mcp-config.json, or register interactively with /mcp add. See the official MCP setup guide.

{
  "mcpServers": {
    "justpen-browser": {
      "command": "justpen-browser-mcp",
      "args": [],
      "tools": ["*"]
    }
  }
}

Running outside the install venv

If Copilot CLI runs outside the venv where justpen-browser-mcp is installed, use an explicit interpreter path:

{
  "mcpServers": {
    "justpen-browser": {
      "command": "/absolute/path/to/.venv/bin/python",
      "args": ["-m", "justpen_browser_mcp"],
      "tools": ["*"]
    }
  }
}

Sanity check

After registering, list MCP servers / tools from within Copilot CLI. The justpen-browser server should appear with its lifecycle, navigation, and interaction tools.

Common pitfalls

  • command not found — the justpen-browser-mcp script is not on the PATH Copilot CLI sees. Use the absolute-path form above.
  • Headless mode — browser_create_instance defaults to headless=true. Pass headless=false to the tool call when you want to watch the browser for debugging.
  • Transport selection — these examples use stdio. The server also supports HTTP when started with --transport http; configure your client for Streamable HTTP at http://127.0.0.1:8931/mcp to use it. See Run the server, including its warning about the lack of built-in authentication.

Reference

See the official local server configuration fields for the config schema. tools: ["*"] makes all server tools available; it does not disable Copilot's tool permission prompts.