Calendar AutoAuth MCP Server

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

Features

• Create calendar events with title, time, description, and location
• Retrieve event details by event ID
• Update existing events (title, time, description, location)
• Delete events
• List events within a specified time range
• 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 via Smithery

To install Calendar AutoAuth Server for Claude Desktop automatically via Smithery:

npx -y @smithery/cli install @raghavared/calendar-mcp --client claude

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/v2/auth/google/callback to the authorized redirect URIs
   • Download the JSON file of your client's OAuth keys
   • Rename the key file to token.json

2. Run Authentication:

   You can authenticate in two ways:

   a. Global Authentication (Recommended):

   # First time: Place token.json in your home directory's .calendar-mcp folder
   mkdir -p ~/.calendar-mcp
   mv token.json ~/.calendar-mcp/
   
   # Run authentication from anywhere
   npx @raghavared/calendar-mcp auth

   b. Local Authentication:

   # Place token.json in your current directory
   # The file will be automatically copied to global config
   npx @raghavared/calendar-mcp auth

   The authentication process will:

   • Look for token.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/v2/auth/google/callback to your authorized redirect URIs

3. Configure in Claude Desktop:

{
  "mcpServers": {
    "calendar": {
      "command": "npx",
      "args": [
        "@raghavared/calendar-mcp"
      ]
    }
  }
}

Docker Support

If you prefer using Docker:

1. Authentication:

docker run -i --rm \
  --mount type=bind,source=/path/to/token.json,target=/token.json \
  -v mcp-calendar:/path \
  -e CALENDAR_OAUTH_PATH=/token.json \
  -e "CALENDAR_CREDENTIALS_PATH=/path/credentials.json" \
  -p 3000:3000 \
  mcp/calendar auth

2. Usage:

{
  "mcpServers": {
    "calendar": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-v",
        "mcp-calendar:/path",
        "-e",
        "CALENDAR_CREDENTIALS_PATH=/path/credentials.json",
        "mcp/calendar"
      ]
    }
  }
}

Usage Examples

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

Create Event

{
  "summary": "Team Meeting",
  "start": {
    "dateTime": "2024-01-20T10:00:00Z"
  },
  "end": {
    "dateTime": "2024-01-20T11:00:00Z"
  },
  "description": "Weekly team sync",
  "location": "Conference Room A"
}

List Events

{
  "timeMin": "2024-01-01T00:00:00Z",
  "timeMax": "2024-12-31T23:59:59Z",
  "maxResults": 10,
  "orderBy": "startTime"
}

Update Event

{
  "eventId": "event123",
  "summary": "Updated Meeting Title",
  "start": {
    "dateTime": "2024-01-20T11:00:00Z"
  },
  "end": {
    "dateTime": "2024-01-20T12:00:00Z"
  }
}

Delete Event

{
  "eventId": "event123"
}

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
• Credentials are stored globally but are only accessible by the current user

Troubleshooting

1. OAuth Keys Not Found

   • Make sure token.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

This project is licensed under the ISC License.

Author

Raghava Reddy

Support

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