Google Calendar AutoAuth MCP Server

Google Calendar AutoAuth MCP Server

A Model Context Protocol (MCP) server for Google Calendar integration in Claude Desktop with auto authentication support. This server enables AI assistants to manage Google Calendar through natural language interactions.

Features

  • Create calendar events with title, description, location, and attendees
  • Update existing calendar events
  • Delete calendar events
  • Retrieve event details
  • List events within a specified time range
  • Search for events by keyword
  • List all available calendars
  • Support for natural language date/time input (e.g., "tomorrow at 2pm", "next monday")
  • Full integration with Google Calendar API
  • Simple OAuth2 authentication flow with auto browser launch
  • Support for both Desktop and Web application credentials
  • Global credential storage for convenience

Installation & Authentication

Installing Manually

  1. Create a Google Cloud Project and obtain credentials:a. Create a Google Cloud Project:
    • Go to Google Cloud Console
    • Create a new project or select an existing one
    • Enable the Google Calendar API for your project

    b. Create OAuth 2.0 Credentials:

    • Go to "APIs & Services" > "Credentials"
    • Click "Create Credentials" > "OAuth client ID"
    • Choose either "Desktop app" or "Web application" as application type
    • Give it a name and click "Create"
    • For Web application, add http://localhost:3000/oauth2callback to the authorized redirect URIs
    • Download the JSON file of your client's OAuth keys
    • Rename the key file to gcp-oauth.keys.json
  2. Run Authentication:You can authenticate in two ways:a. Global Authentication (Recommended):
    # First time: Place gcp-oauth.keys.json in your home directory's .calendar-mcp folder mkdir -p ~/.calendar-mcp mv gcp-oauth.keys.json ~/.calendar-mcp/ # Run authentication from anywhere npx @nchufa/calendar auth
    b. Local Authentication:
    # Place gcp-oauth.keys.json in your current directory # The file will be automatically copied to global config npx @nchufa/calendar auth
    The authentication process will:
    • Look for gcp-oauth.keys.json in the current directory or ~/.calendar-mcp/
    • If found in current directory, copy it to ~/.calendar-mcp/
    • Open your default browser for Google authentication
    • Save credentials as ~/.calendar-mcp/credentials.json

    Note:

    • After successful authentication, credentials are stored globally in ~/.calendar-mcp/ and can be used from any directory
    • Both Desktop app and Web application credentials are supported
    • For Web application credentials, make sure to add http://localhost:3000/oauth2callback to your authorized redirect URIs
  3. Configure in Claude Desktop:

Add the following to your Claude Desktop configuration file:

{ "mcpServers": { "calendar": { "command": "npx", "args": [ "@nchufa/calendar" ] } } }

Available Tools

The server provides the following tools that can be used through Claude Desktop:

1. Create Event (create_event)

Creates a new calendar event.

{ "summary": "Team Meeting", "description": "Weekly team sync to discuss project progress", "location": "Conference Room A", "start": "2025-04-01T14:00:00", "end": "2025-04-01T15:00:00", "attendees": ["colleague@example.com", "manager@example.com"], "reminders": { "useDefault": false, "overrides": [ { "method": "email", "minutes": 30 }, { "method": "popup", "minutes": 10 } ] } }

Natural language date/time is also supported:

{ "summary": "Coffee with John", "location": "Starbucks Downtown", "start": "tomorrow at 2:30pm", "end": "tomorrow at 3:30pm" }

2. Get Event (get_event)

Retrieves details of a specific calendar event.

{ "eventId": "abc123xyz456", "calendarId": "primary" }

3. Update Event (update_event)

Updates an existing calendar event.

{ "eventId": "abc123xyz456", "summary": "Updated Meeting Title", "location": "New Location", "start": "2025-04-01T15:00:00", "end": "2025-04-01T16:00:00" }

4. Delete Event (delete_event)

Deletes a calendar event.

{ "eventId": "abc123xyz456", "calendarId": "primary" }

5. List Events (list_events)

Lists calendar events within a specified time range.

{ "calendarId": "primary", "timeMin": "2025-04-01T00:00:00", "timeMax": "2025-04-07T23:59:59", "maxResults": 10, "orderBy": "startTime" }

6. Search Events (search_events)

Searches for events matching a query.

{ "query": "meeting", "calendarId": "primary", "timeMin": "2025-04-01T00:00:00", "maxResults": 5 }

7. List Calendars (list_calendars)

Lists all available calendars.

{}

Natural Language Date/Time Support

The server supports various natural language formats for dates and times:

  • Specific dates: "2025-04-01T14:00:00" (ISO format)
  • Simple references: "today", "tomorrow", "now"
  • Relative times: "2 hours later", "3 days later"
  • Day references: "next monday", "next tuesday"
  • Combined formats: "tomorrow at 2pm", "monday at 15:30"

This makes it easy to create and update events using natural language instructions.

Security Notes

  • OAuth credentials are stored securely in your local environment (~/.calendar-mcp/)
  • The server uses offline access to maintain persistent authentication
  • Never share or commit your credentials to version control
  • Regularly review and revoke unused access in your Google Account settings

Troubleshooting

  1. OAuth Keys Not Found
    • Make sure gcp-oauth.keys.json is in either your current directory or ~/.calendar-mcp/
    • Check file permissions
  2. Invalid Credentials Format
    • Ensure your OAuth keys file contains either web or installed credentials
    • For web applications, verify the redirect URI is correctly configured
  3. Port Already in Use
    • If port 3000 is already in use, please free it up before running authentication
    • You can find and stop the process using that port

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT

Acknowledgments

Special thanks to GongRzhe and his Calendar-Autoauth-MCP-Server project which served as a foundation for this implementation.

Support

If you encounter any issues or have questions, please file an issue on the GitHub repository.

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security - not tested
A
license - permissive license
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quality - not tested

Enables AI assistants to manage Google Calendar through natural language interactions with features like creating, updating, and deleting events, searching calendars, and supporting natural language date/time inputs.

  1. Features
    1. Installation & Authentication
      1. Installing Manually
    2. Available Tools
      1. 1. Create Event (create_event)
      2. 2. Get Event (get_event)
      3. 3. Update Event (update_event)
      4. 4. Delete Event (delete_event)
      5. 5. List Events (list_events)
      6. 6. Search Events (search_events)
      7. 7. List Calendars (list_calendars)
    3. Natural Language Date/Time Support
      1. Security Notes
        1. Troubleshooting
          1. Contributing
            1. License
              1. Acknowledgments
                1. Support