@mcp-z/mcp-gmail

MCP server for Gmail integration with OAuth authentication, message search, batch operations, and Google Sheets export

Requires Node.js >=20. The examples use npx, included with npm, to run this server and @mcp-z/cli.

Common uses

• Search and read messages
• Send and reply to emails
• Manage labels and export messages to CSV

Transports

MCP supports stdio and HTTP.

Both the 2025 and 2026-07-28 protocol revisions are served, over either transport, from the same server. Your client negotiates whichever it speaks. A 2025 client keeps working with no change, and support for it is not being dropped. The 2026-07-28 revision is stateless, so a client speaking it sends no initialize handshake and carries no session id.

Stdio

{
  "mcpServers": {
    "gmail": {
      "command": "npx",
      "args": ["-y", "@mcp-z/mcp-gmail"]
    }
  }
}

HTTP

{
  "mcpServers": {
    "gmail": {
      "type": "http",
      "url": "http://localhost:9002/mcp",
      "start": {
        "command": "npx",
        "args": ["-y", "@mcp-z/mcp-gmail", "--port=9002"]
      }
    }
  }
}

start is an extension used by npx @mcp-z/cli up to launch HTTP servers for you.

Create a Google Cloud app

1. Go to Google Cloud Console.
2. Create or select a project.
3. Enable the Gmail API.
4. Create OAuth 2.0 credentials (Desktop app).
5. Copy the Client ID and Client Secret.
6. Select your MCP transport (stdio for local and http for remote) and platform

• For stdio, choose "APIs & Services", + Create client, "Desktop app" type
• For http, choose "APIs & Services", + Create client, "Web application" type, add your URL (default is http://localhost:3000/oauth/callback based on the --port or PORT)
• For local hosting, add "http://127.0.0.1" for Ephemeral redirect URL

7. Enable OAuth2 scopes: openid https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/userinfo.email https://mail.google.com/
8. Add test emails

OAuth modes

Configure via environment variables or the env block in .mcp.json. The configuration reference below lists every option.

Loopback OAuth (default)

Environment variables:

GOOGLE_CLIENT_ID=your-client-id
GOOGLE_CLIENT_SECRET=your-client-secret

Example (stdio) - Create .mcp.json:

{
  "mcpServers": {
    "gmail": {
      "command": "npx",
      "args": ["-y", "@mcp-z/mcp-gmail"],
      "env": {
        "GOOGLE_CLIENT_ID": "your-client-id"
      }
    }
  }
}

Example (http) - Create .mcp.json:

{
  "mcpServers": {
    "gmail": {
      "type": "http",
      "url": "http://localhost:3000/mcp",
      "start": {
        "command": "npx",
        "args": ["-y", "@mcp-z/mcp-gmail", "--port=3000"],
        "env": {
          "GOOGLE_CLIENT_ID": "your-client-id"
        }
      }
    }
  }
}

Local (default): omit REDIRECT_URI → ephemeral loopback. Cloud: set REDIRECT_URI to your public /oauth/callback and expose the service publicly.

Note: the start block is a helper in npx @mcp-z/cli up for starting an HTTP server from your .mcp.json. See @mcp-z/cli for details.

Service account

Environment variables:

AUTH_MODE=service-account
GOOGLE_SERVICE_ACCOUNT_KEY_FILE=/path/to/service-account.json

Example:

{
  "mcpServers": {
    "gmail": {
      "command": "npx",
      "args": ["-y", "@mcp-z/mcp-gmail", "--auth=service-account"],
      "env": {
        "GOOGLE_SERVICE_ACCOUNT_KEY_FILE": "/path/to/service-account.json"
      }
    }
  }
}

DCR (self-hosted)

HTTP only. Requires a public base URL. CSV export and /files are disabled in DCR mode; resourceStoreUri is ignored.

{
  "mcpServers": {
    "gmail-dcr": {
      "command": "npx",
      "args": [
        "-y",
        "@mcp-z/mcp-gmail",
        "--auth=dcr",
        "--port=3456",
        "--base-url=https://oauth.example.com"
      ],
      "env": {
        "GOOGLE_CLIENT_ID": "your-client-id",
        "GOOGLE_CLIENT_SECRET": "your-client-secret"
      }
    }
  }
}

How to use

# Start the configured server and list its tools
npx -y @mcp-z/cli inspect --servers gmail --tools

# Call a tool after authorizing Gmail
npx -y @mcp-z/cli call-tool gmail message-search '{"query":"from:[email protected]"}'

Tools

1. categories-list
2. label-add
3. label-delete
4. labels-list
5. message-get
6. message-mark-read
7. message-move-to-trash
8. message-respond
9. message-search
10. message-send
11. messages-export-csv

Resources

1. email

Prompts

1. draft-email
2. query-syntax

Configuration reference

See server.json for all supported environment variables, CLI arguments, and defaults.

Storage backends

OAuth tokens (TOKEN_STORE_URI) and DCR registrations (DCR_STORE_URI) are stored through keyv-registry, which picks an adapter from the URI protocol.

file:// (the default, under ~/.mcp-z/) and memory:// work with no extra setup.

Any other backend needs its adapter installed alongside this server. Adapters are resolved with require(), so a globally installed server finds a globally installed adapter:

npm install -g @mcp-z/mcp-gmail @keyv/redis

TOKEN_STORE_URI=redis://localhost:6379 mcp-gmail

A protocol whose adapter is missing fails at startup naming the package to install.

Documentation

API Docs