Connect the MCP-B Extension to any MCP host

@mcp-b/native-host v1.0.0 Release Notes

See this video for instructions on getting it set up: https://screen.studio/share/E0Lv9lZ7

Release Date: August 02, 2025

Overview

Initial release of @mcp-b/native-host, bridging the MCP-B browser extension to local MCP clients via a Streamable HTTP endpoint (default: http://127.0.0.1:12306/mcp). Based on mcp-chrome.

Installation

Install globally:

npm install -g @mcp-b/native-host

Setup Instructions

Ensure the MCP-B extension is installed and your MCP-enabled site is open in Chrome.

For Clients Supporting Streamable HTTP (e.g., Cursor)

Add to your client's config (e.g., .cursor/mcp.json):

{
  "type": "streamable-http",
  "url": "http://127.0.0.1:12306/mcp"
}

For Stdio-Only Clients (e.g., Claude Desktop)

Use mcp-proxy to bridge Streamable HTTP to stdio.

1. Install mcp-proxy (via uv or pipx):

   uv tool install mcp-proxy

2. Find full path: which mcp-proxy (e.g., /Users/yourusername/.local/bin/mcp-proxy).

3. Add to Claude's config (Settings > Developer > Edit Config):

   {
     "mcpServers": {
       "mcp-b-proxy": {
         "command": "/path/to/mcp-proxy",
         "args": [
           "http://127.0.0.1:12306/mcp",
           "--transport=streamablehttp"
         ],
         "env": {}
       }
     }
   }

Usage Notes

• Disable Web Store extension during dev to avoid port clashes.
• Test with MCP Inspector; tools are domain-prefixed.

What's Next

Custom ports, enhanced logging, and multi-browser support.

Report issues on GitHub. Join Discord.