Google Calendar MCP Server

What is Google Calendar MCP Server?

It is an implementation of the Model Context Protocol (MCP) for Google Calendar that enables interaction with calendar events via CLI or Server-Sent Events (SSE). It is designed for developers and users who want to programmatically manage Google Calendar events through MCP-compatible clients.

How to use Google Calendar MCP Server?

Prerequisites: Node.js 18+, a Google account with Calendar API access, and OAuth 2.0 credentials from Google Cloud Console. Configure environment variables (GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, GOOGLE_REFRESH_TOKEN, etc.) in a .env file, install dependencies (npm install), and build (npm run build). Run as an HTTP/SSE server (npm run start:http) or as a CLI stdio server (npm run start:stdio). Integrate with MCP clients like Claude Desktop by adding the server configuration to the client's config file.

Key features of Google Calendar MCP Server

• List calendar events within a specified time range
• Create new events with attendees, description, and time
• Update existing events (summary, start/end time)
• Delete events from the calendar
• Find free time slots for a given duration
• Supports both HTTP/SSE and CLI stdio transports

Use cases of Google Calendar MCP Server

• Automate event creation and management from an MCP client
• Check availability and schedule meetings without manual calendar checks
• Integrate Google Calendar into larger workflows via MCP
• Build AI assistants that can read and modify calendar events

FAQ from Google Calendar MCP Server

What are the prerequisites to run the server?

Node.js 18 or higher, a Google account, and OAuth 2.0 credentials (client ID, client secret, and a refresh token) from the Google Cloud Console.

How do I obtain a refresh token?

The README provides a JavaScript script (getToken.js) that starts a local HTTP server, generates an OAuth authorization URL, and after user consent prints the refresh token to the console.

What tools does the server expose?

Five tools: list_events, create_event, update_event, delete_event, and find_free_time. Each expects a JSON object with specific parameters (e.g., time range, event details).

How can I integrate the server with Claude Desktop?

Add a JSON entry to Claude's claude_desktop_config.json specifying the absolute path to the built index.js, the command node, and the required environment variables.

What transport modes are supported?

Two modes: HTTP/SSE (server listens on a port, default 3334) and CLI stdio (interactive command-line mode). The SSE endpoint is at GET /sse and message endpoint at POST /messages.