Arc DevTools MCP

arc-devtools-mcp lets your coding agent (such as Gemini, Claude, Cursor or Copilot) control and inspect a live Arc browser. It acts as a Model-Context-Protocol (MCP) server, giving your AI coding assistant access to the full power of DevTools for reliable automation, in-depth debugging, and performance analysis.

Arc browser is built on Chromium, so this server leverages all the power of Chrome DevTools while providing a native Arc experience.

Tool reference | Changelog | Contributing | Troubleshooting

Key features

• Get performance insights: Uses Chrome DevTools to record traces and extract actionable performance insights.
• Advanced browser debugging: Analyze network requests, take screenshots and check the browser console.
• Reliable automation. Uses puppeteer to automate actions in Arc and automatically wait for action results.

Disclaimers

arc-devtools-mcp exposes content of the browser instance to the MCP clients allowing them to inspect, debug, and modify any data in the browser or DevTools. Avoid sharing sensitive or personal information that you don't want to share with MCP clients.

Requirements

• Node.js v20.19 or a newer latest maintenance LTS version.
• Arc browser current version.
• npm.

Getting started

Add the following config to your MCP client:

{
  "mcpServers": {
    "arc-devtools": {
      "command": "npx",
      "args": ["-y", "arc-devtools-mcp@latest"]
    }
  }
}

Note

Using arc-devtools-mcp@latest ensures that your MCP client will always use the latest version of the Arc DevTools MCP server.

MCP Client configuration

Amp

Follow https://ampcode.com/manual#mcp and use the config provided above. You can also install the Arc DevTools MCP server using the CLI:

amp mcp add arc-devtools -- npx arc-devtools-mcp@latest

Claude Code

Use the Claude Code CLI to add the Arc DevTools MCP server (guide):

claude mcp add arc-devtools npx arc-devtools-mcp@latest

Cline

Follow https://docs.cline.bot/mcp/configuring-mcp-servers and use the config provided above.

Codex

Follow the configure MCP guide using the standard config from above. You can also install the Arc DevTools MCP server using the Codex CLI:

codex mcp add arc-devtools -- npx arc-devtools-mcp@latest

On Windows 11

Arc is currently macOS-only. When Arc becomes available on Windows, configure as follows:

[mcp_servers.arc-devtools]
command = "cmd"
args = [
    "/c",
    "npx",
    "-y",
    "arc-devtools-mcp@latest",
]
startup_timeout_ms = 20_000

Copilot CLI

Start Copilot CLI:

copilot

Start the dialog to add a new MCP server by running:

/mcp add

Configure the following fields and press CTRL+S to save the configuration:

• Server name: arc-devtools
• Server Type: [1] Local
• Command: npx
• Arguments: -y, arc-devtools-mcp@latest

Copilot / VS Code

Follow the MCP install guide, with the standard config from above. You can also install the Arc DevTools MCP server using the VS Code CLI:

code --add-mcp '{"name":"arc-devtools","command":"npx","args":["arc-devtools-mcp@latest"]}'

Cursor

Or install manually:

Go to Cursor Settings -> MCP -> New MCP Server. Use the config provided above.

Gemini CLI

Install the Arc DevTools MCP server using the Gemini CLI.

Project wide:

gemini mcp add arc-devtools npx arc-devtools-mcp@latest

Globally:

gemini mcp add -s user arc-devtools npx arc-devtools-mcp@latest

Alternatively, follow the MCP guide and use the standard config from above.

Gemini Code Assist

Follow the configure MCP guide using the standard config from above.

JetBrains AI Assistant & Junie

Go to Settings | Tools | AI Assistant | Model Context Protocol (MCP) -> Add. Use the config provided above. The same way arc-devtools-mcp can be configured for JetBrains Junie in Settings | Tools | Junie | MCP Settings -> Add. Use the config provided above.

Kiro

In Kiro Settings, go to Configure MCP > Open Workspace or User MCP Config > Use the configuration snippet provided above.

Or, from the IDE Activity Bar > Kiro > MCP Servers > Click Open MCP Config. Use the configuration snippet provided above.

Qoder

In Qoder Settings, go to MCP Server > + Add > Use the configuration snippet provided above.

Alternatively, follow the MCP guide and use the standard config from above.

Visual Studio

Click the button to install:

Warp

Go to Settings | AI | Manage MCP Servers -> + Add to add an MCP Server. Use the config provided above.

Your first prompt

Enter the following prompt in your MCP Client to check if everything is working:

Check the performance of https://developers.chrome.com

Your MCP client should open the Arc browser and record a performance trace.

Note

The MCP server will start the browser automatically once the MCP client uses a tool that requires a running browser instance. Connecting to the Arc DevTools MCP server on its own will not automatically start the browser.

Tools

If you run into any issues, checkout our troubleshooting guide.

• Input automation (7 tools)
  • click
  • drag
  • fill
  • fill_form
  • handle_dialog
  • hover
  • upload_file
• Navigation automation (7 tools)
  • close_page
  • list_pages
  • navigate_page
  • navigate_page_history
  • new_page
  • select_page
  • wait_for
• Emulation (3 tools)
  • emulate_cpu
  • emulate_network
  • resize_page
• Performance (3 tools)
  • performance_analyze_insight
  • performance_start_trace
  • performance_stop_trace
• Network (2 tools)
  • get_network_request
  • list_network_requests
• Debugging (4 tools)
  • evaluate_script
  • list_console_messages
  • take_screenshot
  • take_snapshot

Configuration

The Arc DevTools MCP server supports the following configuration options:

• --browserUrl, -u Connect to a running Arc browser instance using port forwarding. Arc uses Chromium remote debugging protocol.

  • Type: string

• --headless Whether to run in headless (no UI) mode.

  • Type: boolean
  • Default: false

• --executablePath, -e Path to Arc executable. Default: /Applications/Arc.app/Contents/MacOS/Arc

  • Type: string

• --isolated If specified, creates a temporary user-data-dir that is automatically cleaned up after the browser is closed.

  • Type: boolean
  • Default: false

• --channel Browser channel to use (Arc only has stable channel, kept for compatibility).

  • Type: string
  • Choices: stable, canary, beta, dev

• --logFile Path to a file to write debug logs to. Set the env variable DEBUG to * to enable verbose logs. Useful for submitting bug reports.

  • Type: string

• --viewport Initial viewport size for the Arc instances started by the server. For example, 1280x720. In headless mode, max size is 3840x2160px.

  • Type: string

• --proxyServer Proxy server configuration for Arc passed as --proxy-server when launching the browser. See https://www.chromium.org/developers/design-documents/network-settings/ for details.

  • Type: string

• --acceptInsecureCerts If enabled, ignores errors relative to self-signed and expired certificates. Use with caution.

  • Type: boolean

• --chromeArg Additional arguments for Arc. Only applies when Arc is launched by arc-devtools-mcp.

  • Type: array

Pass them via the args property in the JSON configuration. For example:

{
  "mcpServers": {
    "arc-devtools": {
      "command": "npx",
      "args": [
        "arc-devtools-mcp@latest",
        "--channel=stable",
        "--headless=true",
        "--isolated=true"
      ]
    }
  }
}

You can also run npx arc-devtools-mcp@latest --help to see all available configuration options.

Concepts

User data directory

arc-devtools-mcp starts an Arc browser instance using the following user data directory:

• macOS: $HOME/.cache/arc-devtools-mcp/arc-profile
• Windows: Coming soon (Arc is currently macOS-only)
• Linux: Not available (Arc is currently macOS-only)

The user data directory is not cleared between runs and shared across all instances of arc-devtools-mcp. Set the isolated option to true to use a temporary user data dir instead which will be cleared automatically after the browser is closed.

Connecting to a running Arc instance

You can connect to a running Arc instance by using the --browser-url option. This is useful if you want to use your existing Arc profile or if you are running the MCP server in a sandboxed environment that does not allow starting a new Arc instance.

Here is a step-by-step guide on how to connect to a running Arc instance:

Step 1: Configure the MCP client

Add the --browser-url option to your MCP client configuration. The value of this option should be the URL of the running Arc instance. http://127.0.0.1:9222 is a common default.

{
  "mcpServers": {
    "arc-devtools": {
      "command": "npx",
      "args": ["arc-devtools-mcp@latest", "--browser-url=http://127.0.0.1:9222"]
    }
  }
}

Step 2: Start Arc with remote debugging

Warning

Enabling the remote debugging port opens up a debugging port on the running browser instance. Any application on your machine can connect to this port and control the browser. Make sure that you are not browsing any sensitive websites while the debugging port is open.

Start Arc with the remote debugging port enabled. Make sure to close any running Arc instances before starting a new one with the debugging port enabled. The port number you choose must be the same as the one you specified in the --browser-url option in your MCP client configuration.

For security reasons, you need to use a non-default user data directory when enabling the remote debugging port. You can specify a custom directory using the --user-data-dir flag. This ensures that your regular browsing profile and data are not exposed to the debugging session.

macOS

/Applications/Arc.app/Contents/MacOS/Arc --remote-debugging-port=9222 --user-data-dir=/tmp/arc-profile-debug

Step 3: Test your setup

After configuring the MCP client and starting Arc with debugging enabled, you can test your setup by running a simple prompt in your MCP client:

Check the performance of https://developers.chrome.com

Your MCP client should connect to the running Arc instance and receive a performance report.

Known limitations

Operating system sandboxes

Some MCP clients allow sandboxing the MCP server using macOS Seatbelt or Linux containers. If sandboxes are enabled, arc-devtools-mcp is not able to start Arc that requires permissions to create its own sandboxes. As a workaround, either disable sandboxing for arc-devtools-mcp in your MCP client or use --browser-url to connect to an Arc instance that you start manually outside of the MCP client sandbox.

Platform availability

Arc browser is currently only available on macOS. Windows and Linux support is planned by the Arc team but not yet available.