Open Claude in Chrome

What is Open Claude in Chrome?

Open Claude in Chrome is an open-source, clean-room reimplementation that connects Claude Code to a Chromium browser with the same 18 MCP tools, removing the official extension’s domain blocklist.

Key Features

• No domain blocklist: Unlike the official extension (which lists 58 blocked domains across categories), Open Claude in Chrome is intended to navigate anywhere.
• Clean-room reimplementation (open source, MIT license): Source code is available under the MIT license.
• Works with any Chromium browser: Supported browsers include Chrome and Edge by default, with additional Chromium browsers mentioned such as Brave, Arc, Opera, Vivaldi, etc.
• Same 18 MCP tools as Claude in Chrome: The project lists 18 tool endpoints and positions them as identical to the official extension.
• Browser automation architecture with three components: An extension (Manifest V3 with CDP-based automation), an MCP server (Node.js process started by Claude Code), and a native messaging host bridge to connect the MCP server to the extension.

How to Use Open Claude in Chrome

1. Prepare prerequisites: Install Node.js v18+ and have a supported Chromium browser installed. Also use Claude Code v2.0.73+.
2. Install extension dependencies:
   • cd host
   • npm install
   • cd ..
3. Load the extension:
   • Open your browser’s extensions page (e.g., chrome://extensions, brave://extensions, edge://extensions).
   • Enable Developer mode.
   • Click Load unpacked and select the extension/ directory.
   • Copy the extension ID shown under the extension name.
4. Register the native messaging host:
   • Run ./install.sh <your-extension-id>.
   • If you use multiple browsers, pass multiple IDs (example format is provided in the repo).
5. Restart the browser: The browser reads native messaging host configs on startup.
6. Add MCP to Claude Code:
   • Run: claude mcp add open-claude-in-chrome -- node /absolute/path/to/host/mcp-server.js
   • The repo suggests determining the absolute path with: echo "node $(pwd)/host/mcp-server.js"
7. Verify: Start a new Claude Code session and test navigation to a site such as reddit.com; the repo includes a screenshot-based verification step.

Use Cases

• Browsing sites that are blocked in the official extension: If the official extension blocks specific domains (the repo enumerates categories like banking, investing, payments/transfers, gambling, dating, and more), Open Claude in Chrome is intended to allow navigation to those domains.
• Reading and extracting page content: Use the provided tools such as get_page_text to extract main article or page text, supporting workflows like quick review or summarization.
• Interacting with web forms: Use form_input to set form values by element reference, which is useful for structured data entry tasks.
• Client-side automation inside a browsing session: Use actions like read_page (accessibility tree), find (locate elements by text/attributes), and navigate/back/forward to progress through multi-step pages.
• Debugging or inspection during automated browsing: Tools such as read_console_messages and read_network_requests help users see console output and network activity encountered by the automation.

FAQ

Q: Which browsers are supported? A: The project states Chrome and Edge only by category, but also supports “any Chromium browser,” listing examples such as Brave, Arc, Opera, and Vivaldi.

Q: How do I install the native messaging host correctly? A: Run ./install.sh with the extension ID shown in your browser’s extensions page. If you use multiple browsers, pass all relevant extension IDs. Then restart the browser before using Claude Code.

Q: How do I connect Open Claude in Chrome to Claude Code? A: Add it as an MCP in Claude Code using claude mcp add open-claude-in-chrome -- node /absolute/path/to/host/mcp-server.js, using the absolute path to host/mcp-server.js.

Q: What should I do if the extension isn’t connecting? A: The repo suggests verifying the extension is loaded and enabled, confirming ./install.sh was run with the correct extension ID, restarting the browser completely, and checking that the native messaging host manifest exists under the browser’s NativeMessagingHosts directory. It also mentions using an absolute path when adding the MCP server.

Q: Does Open Claude in Chrome include the same browser tools as the official extension? A: The repo lists 18 MCP tools and presents them as the “same 18 MCP tools” as Claude in Chrome.

Alternatives

• Use the official “Claude in Chrome” extension: This would match the same general Claude-in-browser workflow, but the repo emphasizes that the official extension includes a domain blocklist.
• Other AI browser automation approaches: Look for tools that integrate an LLM with browser automation via protocols or agent frameworks (the key difference is whether they use MCP-style tool exposure and how they handle browser restrictions).
• Generic browser automation (non-LLM): Automation frameworks can navigate and interact with pages without an LLM tool layer, but they won’t provide the same LLM-facing tool set described in the MCP integration.