Remote MCP Server On Cloudflare 286

🚀 Setting Up a Remote MCP Server on Cloudflare

Let's get a remote MCP server up and running on Cloudflare Workers and integrate OAuth login functionality!

🚀 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/.

🔗 Connecting MCP Inspector to Your Server

To explore your 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 redirected to a (simulated) user/password login page. Enter any email and password to log in.
• After successful login, you should be able to list and call any defined tools!

🔗 Connecting Claude Desktop to Your Local MCP Server

The MCP inspector is great, but what we really want to do is connect it to Claude! Follow Anthropic's Quick Start Guide, go to Settings > Developer > Edit Configuration in Claude Desktop to find your configuration file. Open the file 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 over HTTP. When you open Claude, a browser window should open and allow you to log in. You should be able to see available tools in the bottom right corner. As prompted, Claude should be able to call the tools.

🚀 Deployment to Cloudflare

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

🔗 Calling Your Newly Deployed Remote MCP Server from a Remote MCP Client

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

🔗 Connecting Claude Desktop to Your Remote MCP Server

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

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

🐞 Debugging

If you encounter any issues, restarting Claude or connecting directly to your MCP server using the following command may help.

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

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

rm -rf ~/.mcp-auth