Google Calendar MCP Server is an integration that connects AI assistants to Google Calendar, enabling full calendar management and scheduling capabilities across multiple Google accounts. Key features: - Multi-account and multi-calendar support for simultaneous access to work, personal, or any configured calendars - Complete event lifecycle management including create, update, delete, and search operations - Cross-account conflict detection to identify overlapping events across any combination of calendars - Advanced recurring event modification capabilities - Free/busy availability queries for scheduling optimization - Natural language understanding for parsing dates and times - Intelligent event import from images, PDFs, and web links

Google Calendar MCP Server

A Model Context Protocol (MCP) server that provides Google Calendar integration for AI assistants like Claude.

Features

Quick Start

Prerequisites

1. A Google Cloud project with the Calendar API enabled 2. OAuth 2.0 credentials (Desktop app type)

Google Cloud Setup

1. Go to the Google Cloud Console 2. Create a new project or select an existing one. 3. Enable the Google Calendar API for your project. Ensure that the right project is selected from the top bar before enabling the API. 4. Create OAuth 2.0 credentials: - Go to Credentials - Click "Create Credentials" > "OAuth client ID" - Choose "User data" for the type of data that the app will be accessing - Add your app name and contact information - Add the following scopes (optional): - https://www.googleapis.com/auth/calendar.events and https://www.googleapis.com/auth/calendar - Select "Desktop app" as the application type (Important!) - Save the auth key, you'll need to add its path to the JSON in the next step - Add your email address as a test user under the Audience screen - Note: it might take a few minutes for the test user to be added. The OAuth consent will not allow you to proceed until the test user has propagated. - Note about test mode: While an app is in test mode the auth tokens will expire after 1 week and need to be refreshed (see Re-authentication section below).

Installation

Option 1: Use with npx (Recommended)

Add to your Claude Desktop configuration:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "google-calendar": {
      "command": "npx",
      "args": ["@cocal/google-calendar-mcp"],
      "env": {
        "GOOGLE_OAUTH_CREDENTIALS": "/path/to/your/gcp-oauth.keys.json"
      }
    }
  }
}

⚠️ Important Note for npx Users: When using npx, you must specify the credentials file path using the GOOGLE_OAUTH_CREDENTIALS environment variable.

Option 2: Local Installation

git clone https://github.com/nspady/google-calendar-mcp.git
cd google-calendar-mcp
npm install
npm run build

Then add to Claude Desktop config using the local path or by specifying the path with the GOOGLE_OAUTH_CREDENTIALS environment variable.

Option 3: Docker Installation

git clone https://github.com/nspady/google-calendar-mcp.git
cd google-calendar-mcp
cp /path/to/your/gcp-oauth.keys.json .
docker compose up

See the Docker deployment guide for detailed configuration options including HTTP transport mode.

First Run

1. Start Claude Desktop 2. Ask Claude to authenticate with the Google Calendar MCP server (e.g., "Authenticate with Google Calendar"). This step is required before using any calendar tool — without it, requests will fail with a -32600 error. 3. Complete the OAuth flow in your browser 4. You're ready to use calendar features!

Using Claude Code? The same steps apply — just ask Claude to authenticate with the Google Calendar MCP server from your CLI session before using any calendar tool.

Re-authentication

If you're in test mode (default), tokens expire after 7 days. If you are using a client like Claude Desktop it should open up a browser window to automatically re-auth. However, if you see authentication errors you can also resolve by following these steps:

For npx users:

export GOOGLE_OAUTH_CREDENTIALS="/path/to/your/gcp-oauth.keys.json"
npx @cocal/google-calendar-mcp auth

For local installation:

npm run auth

To avoid weekly re-authentication, publish your app to production mode (without verification): 1. Go to Google Cloud Console → "APIs & Services" → "OAuth consent screen" 2. Click "PUBLISH APP" and confirm 3. Your tokens will no longer expire after 7 days but Google will show a warning about the app being unverified.

See Authentication Guide for details.

Managing Multiple Accounts

Connect multiple Google accounts and use them simulta