Collection of Google-native tools (Gmail, Calendar, Drive, Tasks) for MCP with OAuth management, automated token refresh, and auto re-authentication capabilities.
Author:@vakharwalad23
Updated at:

Workplace & Productivity

Google MCP Tools

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This is a collection of Google-native tools (e.g., Gmail, Calendar) for the MCP protocol, designed to integrate seamlessly with AI clients like Claude or Cursor.

Google MCP server

Quick Install

Click below for one-click install with .mcpb:

Install with Claude MCPB
JSON configs
{
  "mcpServers": {
    "google-mcp": {
      "command": "bunx",
      "args": ["--no-cache", "google-mcp@latest"],
      "env": {
        // Either can be used, but not both
        // Use OAuth
        "GOOGLE_OAUTH_CLIENT_ID": "<your_client_id>",
        "GOOGLE_OAUTH_CLIENT_SECRET": "<your_client_secret>",
        "GOOGLE_OAUTH_TOKEN_PATH": "<path_to_store_tokens> CAN_BE_ANYWHERE_ON_YOUR_SYSTEM",
        // Use Service Account
        "GOOGLE_CLIENT_EMAIL": "<your_service_account_email>",
        "GOOGLE_PRIVATE_KEY": "<your_service_account_private_key>",
        "GMAIL_USER_TO_IMPERSONATE": "<user_to_impersonate>"
      }
    }
  }
}

</user_to_impersonate></your_service_account_private_key></your_service_account_email></path_to_store_tokens></your_client_secret></your_client_id>

What's New in v1.1.0

πŸ†• Major Features

  • Complete Email Attachment Support:
    • βœ‰οΈ Send emails with attachments from local files or Google Drive
    • πŸ“₯ Download all email attachments to local storage
    • πŸ”„ Dual attachment sources: Local file paths or Google Drive file IDs
    • πŸ“ Smart file handling: Automatic MIME type detection and filename sanitization

πŸ”§ Enhanced Email Capabilities

  • Multi-source attachments: Attach files from local storage or Google Drive in the same email
  • Custom filenames: Override original filenames for attachments
  • File size validation: Automatic 25MB Gmail limit enforcement
  • Cross-platform downloads: Auto-detection of Downloads folder on Windows, macOS, and Linux
  • Conflict resolution: Automatic file renaming to prevent overwrites

πŸ“ New & Enhanced Tools

  • google_gmail_send_email: Now supports attachments from local files and Google Drive
  • google_gmail_draft_email: Create drafts with attachments
  • google_gmail_download_attachments: Download all email attachments with customizable path

Features

  • OAuth Management:

    • Refresh expired access tokens automatically
    • Update tokens in the token file without re-authentication
    • Complete re-authentication with automated token cleanup
    • Maintain session continuity across long-running operations
  • Gmail:

    • Send emails with multiple recipients (to, cc, bcc) and attachments from local files or Google Drive.
    • Download all email attachments to local storage with cross-platform support.
    • List emails with custom queries, labels, and result limits.
    • Read specific emails by ID with attachment information.
    • Manage labels (add, remove, list).
    • Draft and delete emails.
  • Calendar:

    • List calendars and set a default calendar.
    • Create events with details (summary, start/end time, attendees, etc.).
    • List upcoming events with customizable filters.
    • Update or delete existing events.
    • Find free time slots for scheduling.
  • Drive:

    • Filter with search queries
    • Sort by modification date or other criteria
    • Customize display count
    • View detailed file metadata
    • Read file content (text, docs, spreadsheets)
    • Create new files with specified content
    • Update existing files
    • Delete files (trash or permanent)
    • Share files with specific permissions
  • Tasks:

    • View all task lists
    • Create new task lists
    • Delete existing task lists
    • Set default task list
    • List tasks with filters
    • View task details
    • Create tasks with title, notes, and due dates
    • Update task properties
    • Mark tasks as complete
    • Delete tasks
  • TODO Plans:

    • Google Contacts: Search and manage contacts.
    • And Many More...

You can chain commands for workflows, e.g.:

"List my unread emails, draft a reply to the latest one, and schedule a follow-up meeting tomorrow at 2 PM."

OAuth Token Management

The server includes built-in OAuth token management to handle expired access tokens gracefully:

  • Automatic Token Refresh: When access tokens expire, you can refresh them without going through the full OAuth flow again
  • Complete Re-authentication: Automatically handle cases where refresh tokens are invalid or expired
  • Persistent Storage: Refreshed tokens are automatically saved to your configured token file path
  • Session Continuity: All Google services are re-initialized with fresh tokens after refresh

Refreshing Tokens

If you encounter authentication errors or want to proactively refresh your tokens, simply ask:

Refresh my Google OAuth tokens

This will:

  1. Use your stored refresh token to get new access tokens
  2. Update the token file with the new credentials
  3. Re-initialize all Google services with fresh authentication
  4. Show you the new token expiration time

Complete Re-authentication

If you get invalid_grant errors or your refresh token has expired, you can start fresh:

Re-authenticate my Google account

This automated process will:

  1. Delete existing tokens from your token file
  2. Start OAuth server to handle the callback
  3. Open browser for fresh authentication
  4. Save new tokens automatically
  5. Re-initialize services with fresh credentials

You'll only need to click "Allow" in the browser - everything else is automated!

Note: If you don't have a valid refresh token, you'll need to go through the initial OAuth authentication flow again.

Manual Installation

  1. Prerequisites:

    • Install Bun:
    brew install oven-sh/bun/bun  # macOS/Linux with Homebrew
    
  2. Set Up OAuth:

    • Create a Google Cloud project in the Google Cloud Console.
    • Set up OAuth 2.0 credentials (Client ID, Client Secret).
    • Choose the type Desktop app.
    • If using test mode, add your email to the test users list.
    • Make sure to enable API access for desired services (Gmail, Calendar, Drive etc.).
  3. Configure Your Client: Edit your claude_desktop_config.json (or equivalent config file for your client):

{
  "mcpServers": {
    "google-mcp": {
      "command": "bunx",
      "args": ["--no-cache", "google-mcp@latest"],
      "env": {
        // Either can be used, but not both
        // Use OAuth
        "GOOGLE_OAUTH_CLIENT_ID": "<your_client_id>",
        "GOOGLE_OAUTH_CLIENT_SECRET": "<your_client_secret>",
        "GOOGLE_OAUTH_TOKEN_PATH": "<path_to_store_tokens>",
        // Use Service Account
        "GOOGLE_CLIENT_EMAIL": "<your_service_account_email>",
        "GOOGLE_PRIVATE_KEY": "<your_service_account_private_key>",
        "GMAIL_USER_TO_IMPERSONATE": "<user_to_impersonate>"
      }
    }
  }
}
  1. Authenticate:
    • The first time you run the server, it will open a browser for OAuth authentication. Follow the prompts to grant access, and tokens will be saved to GOOGLE_OAUTH_TOKEN_PATH.

Usage

Now, ask Claude to use the google-mcp tool.

Send an email to [email protected] with the subject "Meeting Notes" and body "Here are the notes from today."
List my upcoming calendar events for the next 3 days.
Create a calendar event titled "Team Sync" tomorrow at 10 AM for 1 hour.
Refresh my Google OAuth tokens
Re-authenticate my Google account

Transport Support

This MCP server supports both stdio and HTTP transports via environment variables:

Stdio Transport (Default)

# Default mode - uses stdio transport
bun run dev
# Or explicitly
MCP_TRANSPORT=stdio bun run index.ts

HTTP Transport (Streamable HTTP)

# HTTP mode with Streamable HTTP support
MCP_TRANSPORT=http bun run index.ts
# Or with custom port
MCP_TRANSPORT=http PORT=3000 bun run index.ts

When running in HTTP mode, the server provides these endpoints:

  • GET /health - Health check endpoint with session count
  • GET /mcp - Session info and server status
  • POST /mcp - Main MCP JSON-RPC endpoint for sending requests
  • DELETE /mcp - End session endpoint

Session Management

The Streamable HTTP transport uses the official MCP SDK with automatic session management:

  1. Automatic Sessions: The server automatically generates secure session IDs
  2. SSE Streaming: Supports Server-Sent Events for real-time communication
  3. JSON Responses: Falls back to JSON responses when SSE is not available
  4. DNS Protection: Built-in security features for production deployment

Configuration for HTTP Transport

For HTTP transport, configure your client with the server URL:

{
  "mcpServers": {
    "google-mcp-http": {
      "url": "http://localhost:3000/mcp",
      "env": {
        "GOOGLE_OAUTH_CLIENT_ID": "<your_client_id>",
        "GOOGLE_OAUTH_CLIENT_SECRET": "<your_client_secret>",
        "GOOGLE_OAUTH_TOKEN_PATH": "<path_to_store_tokens>"
      }
    }
  }
}

Local Development

git clone https://github.com/vakharwalad23/google-mcp.git
cd google-mcp
bun install

# Run in stdio mode (default)
bun run dev:stdio

# Run in HTTP mode
bun run dev:http

Thank you for using Google MCP Tools! If you have any questions or suggestions, feel free to open an issue or contribute to the project.

Play around with the tools and enjoy!! </path_to_store_tokens></your_client_secret></your_client_id></user_to_impersonate></your_service_account_private_key></your_service_account_email></path_to_store_tokens></your_client_secret></your_client_id>

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