claude-gmail-mcp

A super tiny Gmail MCP server for Claude Code. Lets Claude send, search, and read Gmail on your behalf.

Two backends are supported and auto-selected at startup:

• Gmail API (OAuth) — recommended. No app password. Batch search. Direct Gmail web URLs on every result.
• SMTP/IMAP (app password) — simpler setup. Fallback when the OAuth token isn't present.

I needed something for my projects — there were a bunch around which seemed super complicated. So why not have Claude CLI build one for me :-p

Prerequisites

• uv installed
• One of:
  • A Google Cloud OAuth client (Desktop app) — for the API backend, OR
  • A Gmail App Password — for the SMTP/IMAP backend

Install (Gmail API backend — recommended)

1. In Google Cloud Console, create a project, enable the Gmail API, and configure the OAuth consent screen (External, add your Gmail as a test user). Create an OAuth client of type Desktop app and download the credentials JSON.

2. Run the auth helper, pointing at the downloaded file:

uvx --from claude-gmail-mcp claude-gmail-mcp-auth /path/to/credentials.json

Browser opens → sign in → approve (scope: `gmail.modify`). Refresh token is saved to `~/.config/claude-gmail-mcp/token.json` (perms `600`).

3. Register the MCP server with Claude Code (no env vars needed):

claude mcp add gmail --scope user -- uvx claude-gmail-mcp

Install (SMTP/IMAP backend — fallback)

claude mcp add gmail --scope user \
  -e GMAIL_ADDRESS=you@gmail.com \
  -e GMAIL_APP_PASSWORD=your-app-password \
  -- uvx claude-gmail-mcp

Replace `you@gmail.com` and `your-app-password` with your actual credentials. Drop `--scope user` to install only for the current project directory.

Verify

claude mcp list

You should see `gmail` listed as a configured server. To see which backend is active, run:

uvx claude-gmail-mcp 2>&1 | head -1

Expected: `[gmail-mcp] backend=api` or `[gmail-mcp] backend=imap`. Ctrl-C to exit.

Backend selection

At startup the server picks exactly one backend:

1. Token file at `GMAIL_TOKEN_PATH` (default `~/.config/claude-gmail-mcp/token.json`) exists → API backend.

2. Else `GMAIL_ADDRESS` + `GMAIL_APP_PASSWORD` env vars set → IMAP backend.

3. Else tools return a "no backend configured" error.

To force a switch to the IMAP backend when a token file exists, set `GMAIL_TOKEN_PATH` to a non-existent path (or delete the token file).

Usage

Ask Claude to send an email:

> Send an email to alice@example.com with subject "Hello" and body "Hi from Claude!"

Tools exposed:

• `send_email` — `to`, `subject`, `body`, optional `cc`/`bcc`, `html`, `attachments` (local file paths; unreadable files are skipped with a warning).
• `search_emails` — `queries` (single string or list of strings), `max_results` (per query when a list is passed). Results include the Gmail message ID in hex and a direct Gmail web URL per hit.
• `read_email` — `uid` (the hex ID from `search_emails`). Output includes the Gmail web URL at the top.

Batch search example:

> Search Gmail for "is:unread from:alice" and "is:unread from:bob" — show me both side by side.

Claude passes both queries in a single tool call. The response is sectioned per query. API backend executes the list step in one HTTP roundtrip; IMAP backend iterates.

Attachment example:

> Send an email to alice@example.com with subject "Report" and attach ~/Documents/report.pdf

Publishing to PyPI

python -m build && twine upload dist/*

For Development

git clone https://github.com/pliablepixels/claude-gmail-mcp.git
cd claude-gmail-mcp
uv sync
uv run pytest

Run the server locally:

uv run claude-gmail-mcp

Test with Claude Code using your local copy instead of the published package:

claude mcp add gmail --scope user \
  -- uv run --directory /path/to/claude-gmail-mcp claude-gmail-mcp

(For the IMAP backend add `-e GMAIL_ADDRESS=... -e GMAIL_APP_PASSWORD=...`.)