Remote MCP Server On Cloudflare W6j

🚀 Set Up a Remote MCP Server on Cloudflare

Let's launch a remote MCP server on Cloudflare Workers and equip it with OAuth login!

🚀 Quick Start

Local Development

# Clone the repository
git clone git@github.com:cloudflare/ai.git

# Install dependencies
cd ai
npm install

# Run locally
npx nx dev remote-mcp-server

You should be able to open a browser window at http://localhost:8787/.

Connect the MCP Inspector to Your Server

To explore the new MCP API, you can use the MCP Inspector.

• Start it using npx @modelcontextprotocol/inspector.
• In the inspector, switch the transport type to SSE, enter http://localhost:8787/sse in the URL, and click "Connect".
• You'll be directed to a (simulated) user/password login page. Enter any email and password to log in.
• You should be redirected back to the MCP inspector, and you can now list and call any defined tools!

Connect Claude Desktop to the Local MCP Server

The MCP inspector is great, but we really want to connect it to Claude! Follow Anthropic's Quick Start Guide, go to Settings > Developers > Edit Configuration in Claude Desktop to find your configuration file. Open the file in a text editor and replace it with the following content:

{
  "mcpServers": {
    "math": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "http://localhost:8787/sse"
      ]
    }
  }
}

This will run a local proxy that allows Claude to communicate with your MCP server via HTTP. When you open Claude, a browser window should open and allow you to log in. You should see available tools in the bottom right corner. With the correct prompts, Claude should ask about invoking tools.

Deployment to Cloudflare

1. npx wrangler kv namespace create OAUTH_KV
2. Follow the instructions to add the kv namespace ID to wrangler.jsonc
3. npm run deploy

Call Your Newly Deployed Remote MCP Server from a Remote MCP Client

Just as you did in "Local Development" above, run the MCP inspector: npx @modelcontextprotocol/inspector@latest Then enter your Worker's workers.dev URL (e.g., worker-name.account-name.workers.dev/sse) as the MCP server URL in the inspector and click "Connect". You've connected to your MCP server via a remote MCP client.

Connect Claude Desktop to Your Remote MCP Server

Update the Claude configuration file to point to your workers.dev URL (e.g., worker-name.account-name.workers.dev/sse), and then restart Claude.

{
  "mcpServers": {
    "math": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://worker-name.account-name.workers.dev/sse"
      ]
    }
  }
}

Debugging

If any issues occur, restarting Claude or directly connecting to your MCP server via the following command may help.

npx mcp-remote http://localhost:8787/sse

In rare cases, clearing the files in the ~/.mcp-auth file may be helpful.

rm -rf ~/.mcp