Remote MCP Server On Cloudflare A2w

🚀 Set Up a Remote MCP Server on Cloudflare

Let's launch a running 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/.

📦 Connect 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, enter http://localhost:8787/sse as the address of the MCP server in the URL, and then click "Connect".
• You will be redirected to a (simulated) user/password login screen. Enter any email and password to log in.
• After successful login, you should be redirected back to the MCP inspector, and you can now list and call any defined tools!

📦 Connect 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, and find your configuration file.

Open the file with a text editor 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 enables 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 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 instructions to add the KV namespace ID to wrangler.jsonc.
3. npm run deploy

📦 Connect to 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 the workers.dev URL of your Worker (e.g., worker-name.account-name.workers.dev/sse) as the address of the MCP server, and then click "Connect".

You have now connected to your MCP server through a remote MCP client.

📦 Connect 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 or connecting directly to your MCP server via the command line may be helpful.

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

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

rm -rf ~/.mcp-auth