Remote MCP Server On Cloudflare 45z

🚀 Building a Remote MCP Server on Cloudflare

Let's build a running remote MCP server 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/.

💻 Usage Examples

🔗 Connecting the MCP Inspector to Your Server

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

• Start it with npx @modelcontextprotocol/inspector.
• In the inspector, switch the transport type to SSE, enter http://localhost:8787/sse as the URL of the MCP server, 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 can list and call any defined tools in the MCP inspector!

🔗 Connecting Claude Desktop to Your Local MCP Server

The MCP inspector is great, but what we really want is to connect it to Claude! Follow the Anthropic's Quick Start Guide, open Settings > Developers > Edit Profile in Claude Desktop to find your profile. Open the file with 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. When opening Claude, a browser window should open and prompt you to log in. You should be able to see the available tools. With the correct prompts, Claude should ask 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

💻 Usage Examples (Remote)

🔗 Connecting the MCP Inspector to Your Remote Server

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

🔗 Connecting Claude Desktop to Your Remote MCP Server

Update Claude's 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 you encounter any issues, restarting Claude may help, or try connecting to your MCP server directly via the command line.

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

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

rm -rf ~/.mcp-auth