MCP Server - Google Workspace

A Model Context Protocol (MCP) server for Google Workspace integration, providing tools for Gmail, Google Calendar, and Google Drive access.

Features

• 🔐 Simple Authentication: Environment variable based credentials
• 📧 Gmail: List, read, search emails
• 📅 Calendar: List and create events
• 📁 Drive: File management (coming soon)
• 🔄 Auto Token Refresh: Automatic OAuth token refresh
• 🏢 Multi-User Support: Host applications can decrypt and inject user-specific credentials

Installation

For Individual Use

npm install mcp-server-google-workspace
# or
pnpm add mcp-server-google-workspace

For Development

git clone <repo-url>
cd mcp-server-google-workspace
pnpm install
pnpm build

Authentication

The MCP server reads Google OAuth credentials from environment variables:

# .env
GOOGLE_CLIENT_ID=your_client_id
GOOGLE_CLIENT_SECRET=your_client_secret
GOOGLE_REFRESH_TOKEN=your_refresh_token
GOOGLE_ACCESS_TOKEN=your_access_token  # optional

Multi-User Platforms

For platforms serving multiple users, the host application should:

1. Fetch encrypted credentials from database
2. Decrypt credentials (e.g., using AWS KMS)
3. Pass decrypted credentials as environment variables when starting the MCP server

This keeps the MCP server simple and delegates credential management to the host application.

Available Tools

Gmail Tools

gmail_list_emails

List recent emails from Gmail inbox.

Parameters:

• hours (number, optional): Hours to look back (default: 24)
• maxResults (number, optional): Max emails to return (default: 50)
• query (string, optional): Gmail search query

Example:

{
  "hours": 168,
  "maxResults": 50,
  "query": "from:boss@company.com"
}

gmail_read_email

Read full content of a specific email.

Parameters:

• emailId (string, required): Gmail message ID

gmail_search_emails

Search emails with Gmail query syntax.

Parameters:

• query (string, required): Search query
• maxResults (number, optional): Max results (default: 50)

Query Examples:

• "from:user@example.com subject:meeting"
• "has:attachment after:2025/11/01"
• "is:unread label:important"

Calendar Tools

calendar_list_events

List calendar events for a date range.

Parameters:

• date (string, optional): Start date (YYYY-MM-DD), default: today
• days (number, optional): Number of days (default: 1)
• maxResults (number, optional): Max events (default: 50)

calendar_create_event

Create a new calendar event.

Parameters:

• summary (string, required): Event title
• start (string, required): Start time (ISO 8601)
• end (string, required): End time (ISO 8601)
• description (string, optional): Event description
• location (string, optional): Event location
• attendees (array, optional): Attendee emails

Example:

{
  "summary": "Team Meeting",
  "start": "2025-11-02T10:00:00Z",
  "end": "2025-11-02T11:00:00Z",
  "description": "Quarterly review",
  "attendees": ["team@company.com"]
}

Usage

With Claude Desktop

Add to your Claude Desktop configuration:

{
  "mcpServers": {
    "google-workspace": {
      "command": "npx",
      "args": ["-y", "mcp-server-google-workspace"],
      "env": {
        "GOOGLE_CLIENT_ID": "your_client_id",
        "GOOGLE_CLIENT_SECRET": "your_client_secret",
        "GOOGLE_REFRESH_TOKEN": "your_refresh_token"
      }
    }
  }
}

Programmatic Usage (e.g., with Claude Agent SDK)

For multi-user platforms, decrypt credentials and inject them when starting the server:

import { Agent } from '@anthropic-ai/claude-agent-sdk';

// Your backend decrypts credentials from database
const credentials = await decryptUserCredentials(userId);

const agent = new Agent({
  mcpServers: [{
    command: 'node',
    args: ['path/to/mcp-server-google-workspace/dist/index.js'],
    env: {
      GOOGLE_CLIENT_ID: credentials.clientId,
      GOOGLE_CLIENT_SECRET: credentials.clientSecret,
      GOOGLE_REFRESH_TOKEN: credentials.refreshToken,
    }
  }]
});

Development

# Install dependencies
pnpm install

# Build
pnpm build

# Watch mode
pnpm watch

# Run locally
pnpm dev

Testing

With MCP Inspector

npx @modelcontextprotocol/inspector node dist/index.js

With Environment Variables

cp .env.example .env
# Edit .env with your credentials
pnpm dev

OAuth Setup

To get Google OAuth credentials:

1. Go to Google Cloud Console
2. Create a new project or select existing
3. Enable Gmail API and Google Calendar API
4. Create OAuth 2.0 credentials
5. Add authorized redirect URI
6. Get client ID and client secret
7. Use OAuth playground to get refresh token

Contributing

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

License

MIT

Author

iskifogl