Remote MCP Server On Cloudflare Xce

🚀 Building a Remote MCP Server on Cloudflare

Let's build a remote MCP server 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 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 and enter http://localhost:8787/sse as the URL of the MCP server, then click "Connect".
• You'll be redirected to a (simulated) user/password login screen. 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!

🔗 Connecting Claude Desktop to the Local MCP Server

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

{
  "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 a list of available tools. Depending on the correct prompts, Claude may request to call a tool.

🚀 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

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

Just as you did in the "Local Development" section above, run the MCP Inspector: npx @modelcontextprotocol/inspector@latest Then enter the URL of your worker-name.account-name.workers.dev/sse (for example) as the URL of the MCP server and click "Connect". You've now connected the MCP server to the 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., worker-name.account-name.workers.dev/sse) and 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 ~/.mcp-auth may be helpful.

rm -rf ~/.mcp-auth