Remote MCP Server On Cloudflare 94q

🚀 Building a Remote MCP Server on Cloudflare

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

🚀 Quick Start

📦 Installation

# 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/ to view it.

💻 Usage Examples

Connecting MCP Inspectors 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 to connect to the MCP server, then click "Connect".
• You will 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

Although the MCP inspector is useful, we really want to connect it to Claude! Follow the Anthropic's Quick Start Guide, go to Settings > Developer > Edit Configuration in Claude Desktop 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 over HTTP.

After opening Claude, the browser window should display a login screen. You should be able to see a list of available tools. With the correct prompts, Claude should request to call the tools.

Deployment to Cloudflare

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

Calling 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, in the inspector, enter your Cloudflare Worker URL (e.g., worker-name.account-name.workers.dev/sse) as the URL to connect to the MCP server, and click "Connect".

You have successfully connected your MCP server to 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), and 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 directly connecting to your MCP server via the following command may be helpful.

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

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

rm -rf ~/.mcp