Build a Remote MCP Server on Cloudflare (Without Auth) to Query and read from, write to, and update Google Calendar

This example allows you to deploy a remote MCP server giving your MCP client access to your Google Calendar that doesn't require authentication on Cloudflare Workers.

This MCP server can

1. query your Google Calendar
2. add an event to your GCal
3. edit or update an event in your GCal so you can do it directly from Cursor or Windsurf, leaving your coding flow uninterrupted!

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

Setup Google Calendar API

Create a Google Service account here if you haven't already.

On the service accounts page, select your service account and then click Keys -> click add key -> click create new key, select JSON as the key type, and finally click get private key from JSON. Open that JSON file and select the string corresponding to private key.

Add it and the following variables to your .dev.vars file like so:

GOOGLE_CLIENT_EMAIL="REPLACE-WITH-YOUR-service account email" 
GOOGLE_CALENDAR_ID="REPLACE-WITH-THE-GMAIL-ACCOUNT-OF-THE-CALENDAR-YOU-WANT-TO-QUERY"
GOOGLE_PRIVATE_KEY="REPLACE-WITH-PRIVATE-KEY" 

.dev.vars is for local texting. To deploy your secrets to your deployed Cloudflare Worker/MCP server, run npx wrangler secret put GOOGLE_CLIENT_EMAIL, click enter, and type in your google_client_email. Do that for each secret.

We need to activate the Google Calendar API for a Google Cloud project of our choice (ie Google Calendar API). Use an existing project or create a new one: At the top of the Google Cloud Console dashboard, click on the project selection and “New Project”, enter a name e.g. “chat-with-calendar-mcp" and click “Create”. Then, in the Google API dashboard, click Enable APIs and services. Search for the Google Calendar API and click Enable.

Share your GCal w/ the Google Service Account Email

In your Google Calendar, click settings, then Settings menu, then under Settings for my calendars select the calendar you want to share. Click + Add people and groups and type in your service account email. Give them permission to "Make changes and manage sharing."

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. 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
      ]
    }
  }
}

Restart Claude and you should see the tools become available.