mcp-google-gmail 0.1.4

MCP server for Gmail API — list, read, send, draft, label, and trash emails

mcp-google-gmail

Your AI Assistant's Gateway to Gmail! 📧

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🤔 What is this?

mcp-google-gmail is a Python-based MCP server that acts as a bridge between any MCP-compatible client (like Claude Desktop, Cursor, or Windsurf) and the Gmail API. It allows you to list, read, search, send, draft, label, and trash emails — all driven by AI through natural language.

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🚀 Quick Start

Essentially the server runs in one line: uvx mcp-google-gmail@latest.

This command will automatically download the latest code and run it. We recommend always using @latest to ensure you have the newest version with the latest features and bug fixes.

1. ☁️ Prerequisite: Google Cloud Setup

   • You must configure Google Cloud Platform credentials and enable the Gmail API first.
   • ➡️ Jump to the Detailed Google Cloud Platform Setup guide below.

2. 🐍 Install uv

   • uvx is part of uv, a fast Python package installer. Install it if you haven't:

     # macOS / Linux
     curl -LsSf https://astral.sh/uv/install.sh | sh
     # Windows
     powershell -c "irm https://astral.sh/uv/install.ps1 | iex"
     

3. 🔐 Authenticate

   • Run the built-in auth command to set up your credentials:

     # Point to your OAuth credentials file
     GMAIL_CREDENTIALS_PATH="/path/to/credentials.json" uvx mcp-google-gmail@latest auth
     

   • This opens your browser for Google sign-in. After granting permission, a token.json is saved automatically.
   • You only need to do this once — subsequent runs use the cached token.

4. 🏃 Run the Server!

   uvx mcp-google-gmail@latest
   

5. 🔌 Connect your MCP Client

   • Configure your client (e.g., Claude Desktop) to connect to the running server.
   • ➡️ See Usage with Claude Desktop for config examples.

You're ready! Start issuing commands via your MCP client.

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✨ Key Features

• Full Gmail Access: Read, search, send, draft, label, and trash emails.
• 15 Tools covering all common Gmail operations.
• Flexible Authentication: Supports OAuth 2.0, Service Accounts, Base64 injection, and Application Default Credentials.
• Pagination: All list operations support page_token and max_results.
• Attachments: Send emails with file attachments.
• Reply Threading: Reply to existing threads with proper In-Reply-To headers.
• HTML Email: Send plain text and/or HTML bodies.
• Stdio & SSE Transports: Works with Claude Desktop, Cursor, and remote/container deployments.

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🔐 Authentication

The auth Command

Before using the MCP server, authenticate with Gmail:

# Using OAuth credentials (interactive — opens browser)
GMAIL_CREDENTIALS_PATH="/path/to/credentials.json" uvx mcp-google-gmail@latest auth

# Specify where to save the token
GMAIL_CREDENTIALS_PATH="/path/to/credentials.json" \
GMAIL_TOKEN_PATH="/path/to/token.json" \
uvx mcp-google-gmail@latest auth

On success, you'll see:

Credentials path: /path/to/credentials.json
Token path:       token.json

Authenticated as: [e-mail]
Total messages:   12345
Token saved to:   token.json

Authentication Priority

The server checks for credentials in this order:

1. GMAIL_CREDENTIALS_CONFIG — Base64-encoded service account JSON (env var)
2. GMAIL_SERVICE_ACCOUNT_PATH — Path to service account key file
3. GMAIL_TOKEN_PATH — Path to existing OAuth token
4. GMAIL_CREDENTIALS_PATH — Path to OAuth credentials (interactive browser flow)
5. Application Default Credentials — GOOGLE_APPLICATION_CREDENTIALS / gcloud / GCP metadata

Method A: OAuth 2.0 (Personal Accounts) 🧑‍💻

Best for personal use or local development.

1. Set up OAuth credentials in Google Cloud Console (see GCP Setup)
2. Run mcp-google-gmail auth to authenticate via browser
3. Token is cached for future use with automatic refresh

• GMAIL_CREDENTIALS_PATH — Path to OAuth credentials.json (default: credentials.json)
• GMAIL_TOKEN_PATH — Where to store the token (default: token.json)

Method B: Service Account (Servers/Automation) ✅

Best for headless environments. Requires domain-wide delegation for accessing user mailboxes.

• GMAIL_SERVICE_ACCOUNT_PATH — Path to service account JSON key (default: service_account.json)

Method C: Base64-Encoded Credentials (Containers) 🔒

Best for Docker, Kubernetes, CI/CD where file mounting is impractical.

• GMAIL_CREDENTIALS_CONFIG — Base64-encoded content of your service account JSON
• Generate with: base64 -w 0 service_account.json

Method D: Application Default Credentials (GCP) 🌐

Best for Google Cloud environments (Cloud Run, GKE, Compute Engine).

• Uses GOOGLE_APPLICATION_CREDENTIALS or gcloud auth application-default login
• No additional env vars needed — used as automatic fallback

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🛠️ Available Tools (15 Total)

Read Operations

• gmail_list_messages — List messages with query, labels, pagination (1-500 per page)

  • query (optional): Gmail search query (e.g. "is:unread", "from:[e-mail]")
  • label_ids (optional): Filter by label IDs (e.g. ["INBOX"])
  • max_results (optional, default 20): Messages per page (1-500)
  • page_token (optional): Token for next page
  • include_spam_trash (optional, default false): Include spam/trash
  • Returns: {messages: [{id, thread_id, snippet, subject, from, date}], next_page_token, result_size_estimate}

• gmail_get_message — Get full message by ID (headers, body, attachments)

  • message_id: The Gmail message ID
  • Returns: {id, thread_id, subject, from, to, cc, date, body_text, body_html, labels, attachments}

• gmail_search_messages — Search with Gmail query syntax, returns compact summaries (1-100 per page). Use gmail_get_message to read the full body of a result.

  • query: Gmail search query (e.g. "has:attachment after:2024/01/01")
  • max_results (optional, default 10): Results per page (1-100)
  • page_token (optional): Token for next page
  • Returns: {messages: [{id, thread_id, snippet, subject, from, to, date, labels}], next_page_token, result_size_estimate}

• gmail_list_drafts — List drafts with pagination and query filter

  • max_results (optional, default 20): Drafts per page (1-500)
  • page_token (optional): Token for next page
  • query (optional): Gmail search query to filter drafts
  • Returns: {drafts: [{draft_id, message_id, subject, to, snippet}], next_page_token, result_size_estimate}

Send Operations

• gmail_send_message — Send email with to/cc/bcc, HTML body, attachments, reply threading

  • to, subject, body (required)
  • cc, bcc, html_body, attachment_paths (optional)
  • reply_to_message_id, thread_id (optional, for threading)
  • Returns: {id, thread_id, label_ids}

• gmail_create_draft — Create a draft without sending (same params as send)

  • Returns: {draft_id, message_id}

• gmail_update_draft — Update an existing draft (merges provided fields with existing)

  • draft_id (required), all other fields optional
  • Returns: {draft_id, message_id}

• gmail_delete_draft — Permanently delete a draft

  • draft_id (required)
  • Returns: {success: true}

• gmail_send_draft — Send an existing draft

  • draft_id (required)
  • Returns: {message_id, thread_id}

Label Operations

• gmail_list_labels — List all labels (system and user-created)

  • Returns: {labels: [{id, name, type}]}

• gmail_create_label — Create a new label (supports nesting with /)

  • name: Label name (e.g. "Projects/Work")
  • Returns: {id, name}

• gmail_delete_label — Delete a user label (system labels cannot be deleted)

  • label_id: The label ID
  • Returns: {success: true}

• gmail_modify_message_labels — Add/remove labels from a message

  • message_id (required)
  • add_label_ids (optional): Label IDs to add
  • remove_label_ids (optional): Label IDs to remove
  • Returns: {id, label_ids}

Trash Operations

• gmail_trash_message — Move a message to trash (auto-deleted after 30 days)

  • message_id: The message ID
  • Returns: {id, label_ids}

• gmail_untrash_message — Restore a message from trash

  • message_id: The message ID
  • Returns: {id, label_ids}

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🔌 Usage with Claude Desktop

Add the server config to your claude_desktop_config.json:

🔵 Config: uvx + OAuth (Recommended for personal use)

{
  "mcpServers": {
    "gmail": {
      "command": "uvx",
      "args": ["mcp-google-gmail@latest"],
      "env": {
        "GMAIL_CREDENTIALS_PATH": "/path/to/credentials.json",
        "GMAIL_TOKEN_PATH": "/path/to/token.json"
      }
    }
  }
}

🍎 macOS Note: If you get a spawn uvx ENOENT error, use the full path:

"command": "/Users/yourusername/.local/bin/uvx"

🔵 Config: uvx + Service Account

{
  "mcpServers": {
    "gmail": {
      "command": "uvx",
      "args": ["mcp-google-gmail@latest"],
      "env": {
        "GMAIL_SERVICE_ACCOUNT_PATH": "/path/to/service_account.json"
      }
    }
  }
}

🟡 Config: Development (from cloned repo)

{
  "mcpServers": {
    "gmail": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/mcp-gmail", "mcp-google-gmail"]
    }
  }
}

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⚙️ Usage with Cursor / Windsurf

{
  "mcpServers": {
    "gmail": {
      "command": "uvx",
      "args": ["mcp-google-gmail@latest"],
      "env": {
        "GMAIL_CREDENTIALS_PATH": "/path/to/credentials.json",
        "GMAIL_TOKEN_PATH": "/path/to/token.json"
      }
    }
  }
}

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🐳 SSE Transport (Remote / Container)

uv run mcp-google-gmail --transport sse

Variable	Default	Description
HOST / FASTMCP_HOST	0.0.0.0	Bind address
PORT / FASTMCP_PORT	8000	Listen port

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☁️ Google Cloud Platform Setup (Detailed)

This setup is required before running the server.

1. Create/Select a GCP Project — Go to the Google Cloud Console
2. Enable the Gmail API — Navigate to "APIs & Services" → "Library", search for "Gmail API", click Enable
3. Configure OAuth Consent Screen — Go to "APIs & Services" → "OAuth consent screen", select External, fill in app name and contact email, add the scope https://www.googleapis.com/auth/gmail.modify
4. Create OAuth Credentials — Go to "APIs & Services" → "Credentials" → "Create Credentials" → "OAuth 2.0 Client ID", select Desktop application
5. Download Credentials — Click the download button and save as credentials.json
6. Authenticate — Run the auth command:

   GMAIL_CREDENTIALS_PATH="/path/to/credentials.json" uvx mcp-google-gmail@latest auth
   

   Complete the browser sign-in. A token.json will be saved for future use.

For Service Accounts: Go to Credentials → Create Credentials → Service Account, create a key (JSON), download it. Note: Service accounts require domain-wide delegation for Gmail access.

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🔧 Environment Variables Reference

Variable	Default	Description
GMAIL_CREDENTIALS_CONFIG	—	Base64-encoded service account JSON
GMAIL_SERVICE_ACCOUNT_PATH	service_account.json	Path to service account key file
GMAIL_TOKEN_PATH	token.json	Path to OAuth token file
GMAIL_CREDENTIALS_PATH	credentials.json	Path to OAuth client credentials file
HOST / FASTMCP_HOST	0.0.0.0	SSE transport bind address
PORT / FASTMCP_PORT	8000	SSE transport port

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💬 Example Prompts for Claude

• "List my 10 most recent unread emails"
• "Search for emails from [e-mail] with attachments"
• "Send an email to [e-mail] with subject 'Meeting Notes' and the body 'Here are the notes from today.'"
• "Create a draft reply to the last email from my manager"
• "Label all emails from [e-mail] as 'Newsletters'"
• "Trash all promotional emails from the last week"
• "Show me the full content of message ID abc123"
• "What are my unread emails about project deadlines?"

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🤝 Contributing

Contributions are welcome! Please open an issue to discuss bugs or feature requests. Pull requests are appreciated.

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📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

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🙏 Credits

• Built with FastMCP
• Uses Google API Python Client
• Inspired by mcp-google-sheets