Gmail Attachments MCP Server

gmail-attachments-mcp

A focused Model Context Protocol server (and standalone CLI) for downloading Gmail attachments to disk. Three tools, read-only OAuth scope, no extra surface area.

Built because the hosted claude.ai Gmail connector in Claude Desktop returns attachment IDs and metadata only — not the actual bytes. This server fills that gap for any MCP client (Claude Code, Claude Desktop, Cursor, Cline, etc.), and also works as a plain CLI for cron jobs and shell scripts.

If you used @GongRzhe/Gmail-MCP-Server (1.1k★, archived 2026-03-03) for its attachment-download workflow, this is a minimal successor focused on that single capability.

Features

• 3 MCP tools — gmail_search, gmail_download_thread_attachments, gmail_download_latest_matching. That's the whole API.
• Read-only OAuth scope (gmail.readonly) — can't send, delete, or modify mail.
• Works as both an MCP server and a standalone CLI — same code, same auth token, both surfaces.
• Env-var-driven config — GMAIL_MCP_CREDENTIALS, GMAIL_MCP_TOKEN, GMAIL_MCP_DEFAULT_DEST_DIR.
• Cron-friendly — once authorized, the cached refresh token lets headless jobs run indefinitely.

Install

pip install gmail-attachments-mcp
# or, with uv:
uv tool install gmail-attachments-mcp

One-time setup (~10 minutes)

You need a Google Cloud OAuth client. The server runs entirely on your machine; nothing leaves it.

1. Sign in to Google Cloud Console with the Gmail account whose attachments you want to download.
2. Create a project (or pick an existing one).
3. Enable the Gmail API: console.cloud.google.com/apis/library/gmail.googleapis.com.
4. Configure the OAuth consent screen under APIs & Services → OAuth consent screen:
   • Google Workspace users: User type = Internal (no app verification needed).
   • Personal Gmail users: User type = External. Add your own Gmail address as a test user under "Test users".
5. APIs & Services → Credentials → + Create credentials → OAuth client ID
   • Application type: Desktop app
   • Download the JSON.
6. Run setup:

gmail-attachments-mcp setup --import-credentials ~/Downloads/client_secret_*.json

A browser window opens for OAuth consent. After consent, a refresh token is cached at ~/.config/gmail-attachments-mcp/token.json (or $XDG_CONFIG_HOME/gmail-attachments-mcp/).

Verify:

gmail-attachments-mcp status
gmail-attachments-mcp search "has:attachment newer_than:7d" --max 3

See docs/setup-google-oauth.md for screenshots and troubleshooting.

Use it from Claude Code

claude mcp add --scope user gmail-attachments gmail-attachments-mcp -- serve

Then in any Claude Code session:

Use the gmail-attachments MCP to download the latest CV from careers@example.com to ~/CVs.

Use it from Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (Mac) or %APPDATA%/Claude/claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "gmail-attachments": {
      "command": "gmail-attachments-mcp",
      "args": ["serve"]
    }
  }
}

Restart Claude Desktop. See docs/claude-desktop.md for details.

Use it from Cursor / Cline / Continue / others

Any MCP client that supports stdio servers. Point it at the same gmail-attachments-mcp serve command. See docs/other-clients.md.

Use it from the shell or cron

# Search
gmail-attachments-mcp search "from:noreply@stripe.com has:attachment newer_than:30d"

# Download every attachment from a specific thread
gmail-attachments-mcp thread 19db831fab15b507 --dest ~/Invoices

# Download from the latest match, only PDFs
gmail-attachments-mcp latest "from:hr@example.com has:attachment" --dest ~/CVs --ext .pdf,.docx

Cron example — pull CV attachments hourly:

0 * * * * /usr/local/bin/gmail-attachments-mcp latest "to:careers@example.com has:attachment newer_than:2d" --dest ~/CVs --ext .pdf,.docx >> ~/.cache/gmail-attachments-mcp.log 2>&1

The 3 MCP tools

gmail_search(query, max_results=10)

Returns thread summaries with attachment filenames. Use Gmail's standard query syntax.

[
  {
    "thread_id": "19db831fab15b507",
    "subject": "Folon Q3 2026 Quarterly Product Recap",
    "sender": "Manon Muhtasin Rahman <manon@example.com>",
    "date": "Thu, 23 Apr 2026 08:35:00 +0600",
    "snippet": "Hi everyone, Attached is...",
    "message_count": 1,
    "attachment_count": 1,
    "attachment_filenames": ["Folon Quarterly Report Q3 2026.pdf"]
  }
]

gmail_download_thread_attachments(thread_id, dest_dir?, extensions?)

Downloads every attachment in a thread to disk. Returns path, size_bytes, mime_type, original_filename per file.

gmail_download_latest_matching(query, dest_dir?, extensions?)

Convenience: search + download from the single most recent match, in one call.

Configuration

All paths can be overridden via environment variables.

Security

• Token storage: refresh token is written to ~/.config/gmail-attachments-mcp/token.json with mode 0600. Anyone with shell access to your account can read your Gmail. Treat the file like a password.
• OAuth scope: default is gmail.readonly. Cannot send, delete, or modify mail. If you change $GMAIL_MCP_SCOPES, you're on the hook for the consequences.
• Credential file: your OAuth client secret JSON is not a password — it identifies your app to Google. But never commit it. The included .gitignore blocks the common filenames.
• OAuth client: your client lives in your Google Cloud project. There's no central server, no telemetry, nothing leaves your machine.

Troubleshooting

No valid Gmail token when invoked from Claude Desktop / cron The first OAuth flow requires a browser. Run gmail-attachments-mcp setup once in a terminal where a browser can open. Subsequent runs use the cached refresh token.

Token has been expired or revoked Refresh tokens stay valid as long as you use them at least every 6 months and don't revoke them at myaccount.google.com/permissions. Re-auth:

gmail-attachments-mcp setup --reauth

Access blocked: This app's request is invalid On personal Gmail, your OAuth consent screen needs your address listed under Test users. Workspace users should select Internal audience to avoid this.

HttpError 403: Request had insufficient authentication scopes You changed $GMAIL_MCP_SCOPES without re-authorizing. Run gmail-attachments-mcp setup --reauth.

Comparison with other Gmail MCP servers

Pick this one if you want a tiny, focused, read-only tool. Pick a fuller one if you also need to send mail, manage labels, drafts, threads, etc.

Authentication — bring your own Google OAuth client

There are no API keys and no shipped secrets. The server authenticates to your Google account with an OAuth client you create, and caches a refresh token locally. The author has zero access to your data.

• Why your own client? Google's restricted scopes (here, gmail.readonly) can't be redistributed in a shared app, and an unverified shared app is capped at 100 users. "Bring your own OAuth client" is the standard pattern for personal-data MCP servers.
• What you need: a free Google Cloud project, the Gmail API enabled, an OAuth consent screen, and a Desktop OAuth client. Full walkthrough → docs/setup-google-oauth.md.
• Where your token lives: ~/.config/gmail-attachments-mcp/token.json (mode 0600). Delete it to revoke locally; revoke fully at myaccount.google.com/permissions.
• No hosted/SaaS option — everything runs locally; your mail never touches a third-party server.

Related tools

Part of a small family of focused, local MCP servers for Google Workspace data the hosted connectors don't expose:

• gmail-attachments-mcp — download Gmail attachment bytes to disk (this repo)
• google-drive-comments-mcp — read comment threads on Docs/Sheets/Slides
• google-drive-files-mcp — move/organize Drive files

They can share one OAuth login or stay isolated — see each repo's setup.

License

MIT. See LICENSE.

Contributing

Issues and PRs welcome. Run pytest and ruff check src tests before submitting.

git clone https://github.com/zayansalman/gmail-attachments-mcp
cd gmail-attachments-mcp
pip install -e ".[dev]"
pytest