DoubleTick Server

Open-source CLI and MCP server for email read tracking via Gmail. Know when your emails are opened — from the terminal.

Works with the DoubleTick backend. Tracks from the CLI show up alongside tracks from the Chrome extension.

Install

npm install -g doubletick-cli

Quick Start

# 1. Log in with your Gmail account (one-time)
doubletick login

# 2. Send a tracked email
doubletick send --to [email protected] --subject "Q1 Planning" --body "Hi Jane, here are the numbers..."

# 3. Check if they read it
doubletick status --last

Commands

doubletick login

Authenticate with Gmail and DoubleTick. Opens your browser for Google sign-in. One-time setup — credentials are stored locally in ~/.doubletick/credentials.json.

doubletick logout

Remove stored credentials.

doubletick send

Send a tracked email. Injects a read-tracking pixel, sends via Gmail API, and registers the track.

# Send a tracked email (body is markdown by default)
doubletick send --to [email protected] --subject "Hi" --body "Hello **Jane**"

# HTML body instead of markdown
doubletick send --to [email protected] --subject "Hi" --body "<h1>Hello</h1>" --html

# Body from file
doubletick send --to [email protected] --subject "Hi" --body-file ./email.md

# With CC/BCC
doubletick send --to [email protected] --cc "[email protected]" --subject "Hi" --body "Hello"

doubletick status

Check if a tracked email has been opened.

# Most recent tracked email
doubletick status --last

# Find by recipient
doubletick status --to [email protected]

# By tracking ID
doubletick status abc-123

doubletick dashboard

List all your tracked emails with open rates and stats.

doubletick dashboard
doubletick dashboard --limit 50

MCP Server

DoubleTick works as an MCP server so AI agents (Claude Code, Claude Desktop, etc.) can send and track emails natively.

Setup

Add to your Claude configuration:

{
  "mcpServers": {
    "doubletick": {
      "command": "npx",
      "args": ["-y", "doubletick-cli"]
    }
  }
}

You must run doubletick login first — the MCP server uses the same stored credentials.

Tools

Tool	Description
send_tracked_email	Send an email with read tracking
check_tracking_status	Check if a tracked email has been opened
list_tracked_emails	List recent tracked emails with stats

How It Works

1. You compose an email (text or markdown)
2. The CLI converts it to HTML, generates a tracking ID, and injects a 1x1 tracking pixel
3. The email is sent via the Gmail API
4. The track is registered with DoubleTick's backend
5. When the recipient opens the email, the pixel fires and the open is logged
6. You check the status via doubletick status

The entire DoubleTick backend (pixel serving, open logging, deduplication, device detection) works unchanged. The CLI is just a new way to inject the pixel — replacing the Chrome extension's role for terminal/agent workflows.

Architecture

doubletick CLI / MCP server
  ├── Gmail API        → send emails
  └── DoubleTick API   → register tracks, check status
        ├── GET  /img?t=<id>   → tracking pixel
        ├── POST /track        → register tracked email
        ├── GET  /status?id=   → check opens
        └── GET  /dashboard    → list tracked emails

Requirements

• Node.js 18+
• A Gmail account
• A DoubleTick account (free tier: 5 tracked emails/week)

License

MIT