Building a Chrome Extension SaaS with AI in a Weekend

SaaS doesn’t need to be a website. I created an AI-powered Chrome extension that writes cold emails directly inside Gmail and turned it into a subscription product.

Why a Chrome Extension?

• Built-in distribution via Chrome Web Store

• Easy user activation (click-to-use)

• Integrates where users already are

Tools & Stack

• Frontend: Vanilla JS + Manifest V3

• Backend: Firebase Functions

• AI: OpenRouter

• Billing: Gumroad

Key Features

• Highlight text → AI rewrites into cold email

• Auto-fills recipient name and context

• Saves output to user dashboard (optional)

Build Steps

• Base extension: Use V3 manifest + content scripts

• Add popup UI: Clean UI with AI prompt input

• Integrate OpenRouter: Inject prompt & handle API call

• Deploy to Chrome Web Store

Monetization

• Offer free 10 credits/day

• Use Gumroad for license keys

• Upgrade to remove limits

Build One Fast

Extensions are underrated. Combine with AI and solve one pain point. Test demand fast, and monetize with ease.

👉 https://gum.co/u/rgikbz7g