Jenny —
Cold Email Automation Extension

The Problem

Manual Outreach at Scale is Broken

• Time cost — sending 100+ individual emails manually takes several hours per week
• Account risk — bulk tools route outside Gmail, hurting deliverability and risking bans
• No visibility — no way to know which recipients opened emails without external tools
• No safety net — one Google block can silently kill an entire campaign with no alert

The Solution

Gmail-Native Automation with Smart Protection

Jenny sends directly through the Gmail API using the user's own account and OAuth 2.0 tokens — preserving sender reputation and deliverability. A real-time block detector monitors every send; if Google flags any message, the campaign terminates immediately to protect the account. WebSocket-powered open tracking reports back exactly who opened, when.

MV3 Service Worker Constraints

Persistent Logic Without Persistent Workers

Manifest V3 service workers are ephemeral — they shut down after ~30s of inactivity, breaking long-running campaigns. Jenny works around this by offloading all stateful campaign logic to the Express.js backend. The extension's service worker acts as a thin relay: it starts a campaign run, then the backend drives execution independently, pinging the extension via WebSocket only when an event (open, block, completion) occurs.

Real-Time Open Tracking

Pixel → Webhook → WebSocket Pipeline

Each outgoing email has a unique 1×1 PNG tracking pixel URL embedded in the HTML body. When a recipient opens the email, their client fetches the pixel — hitting a lightweight Express endpoint that records the open event in PostgreSQL with a timestamp and IP hash. A WebSocket message is immediately broadcast to the connected extension popup, updating the live campaign dashboard without polling.