nspady/google-calendar-mcp

A Model Context Protocol (MCP) server that provides Google Calendar integration for AI assistants like Claude.
I also built Cocal , the calendar integration I wanted for chat: a visual calendar inside Claude that shows your whole day around a proposed time, plus booking links and invites you manage from the conversation. It's hosted, so it works on desktop and mobile with no Google Cloud setup.
Real Cocal UI with sample calendar data. Click either screenshot to enlarge.
Try Cocal →
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Features
- **Multi-Account Support**: Connect multiple Google accounts (e.g., work, personal) and query them simultaneously
- **Multi-Calendar Support**: List events from multiple calendars in a single request
- **Cross-Account Conflicts**: Detect overlapping events across any combination of calendars
- **Event Management**: Create, update, delete, and search calendar events
- **Recurring Events**: Advanced modification capabilities for recurring events
- **Free/Busy Queries**: Check availability across calendars
- **Smart Scheduling**: Natural language understanding for dates and times
- **Intelligent Import**: Add calendar events from images, PDFs, or web links
Quick Start
> Don't want to set up a Google Cloud project? Cocal is a hosted option that works in Claude on desktop and mobile.
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
**⚠️ 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**
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**
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:**
**For local installation:**
**To avoid weekly re-authentication**, publish your app to production mode (without verification):