123hi123/remote-mcp-server-authless

Building a Remote MCP Server on Cloudflare (With API Key Authentication)

This example allows you to deploy a remote MCP server with API key authentication on Cloudflare Workers. The server now requires a valid API key to access the MCP tools, providing better security for your deployment.

Get started:

This will deploy your MCP server to a URL like: remote-mcp-server-authless.<your-account>.workers.dev/sse

Alternatively, you can use the command line below to get the remote MCP Server created on your local machine:

npm create cloudflare@latest -- my-mcp-server --template=cloudflare/ai/demos/remote-mcp-authless

API Key Authentication

The MCP server now includes API key authentication. By default, the API key is set to "password", but you can customize this by:

1. Environment Variable: Set MCP_API_KEY in your Cloudflare Worker's environment variables
2. Wrangler Config: Modify the vars.MCP_API_KEY value in wrangler.jsonc

Setting a Custom API Key

To set a custom API key, update the wrangler.jsonc file:

{
  "vars": {
    "MCP_API_KEY": "your-secure-api-key-here"
  }
}

Authentication Methods

The server accepts API keys via multiple methods:

• Authorization Header: Authorization: Bearer your-api-key
• X-API-Key Header: X-API-Key: your-api-key
• Query Parameter: ?api_key=your-api-key

Customizing your MCP Server

To add your own tools to the MCP server, define each tool inside the init() method of src/index.ts using this.server.tool(...).

Connect to Cloudflare AI Playground

You can connect to your MCP server from the Cloudflare AI Playground, which is a remote MCP client:

1. Go to https://playground.ai.cloudflare.com/
2. Enter your deployed MCP server URL (remote-mcp-server-authless.<your-account>.workers.dev/sse)
3. Provide your API key when prompted
4. You can now use your MCP tools directly from the playground!

Connect Claude Desktop to your MCP server

You can also connect to your remote MCP server from local MCP clients, by using the mcp-remote proxy.

To connect to your MCP server from Claude Desktop, follow Anthropic's Quickstart and within Claude Desktop go to Settings > Developer > Edit Config.

Update with this configuration:

{
  "mcpServers": {
    "calculator": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "http://localhost:8787/sse",  // or remote-mcp-server-authless.your-account.workers.dev/sse
        "password"  // Replace with your actual API key
      ]
    }
  }
}

Note: The third argument in the args array is your API key. Make sure to replace "password" with your actual API key.

Restart Claude and you should see the tools become available after authentication.

Health Check

You can check if your server is running by visiting the root endpoint:

• GET / or GET /health - Returns server status (no authentication required)

Security Features

• All MCP endpoints (/sse, /mcp) now require valid API key authentication
• Multiple authentication methods supported for flexibility
• Configurable API keys via environment variables
• Health check endpoint remains publicly accessible