How to Add Subscriptions to a Chrome Extension: The Complete Guide

Why Monetizing Chrome Extensions Is Hard

You've built a Chrome extension that people love. Now you want to charge for it. Simple, right?

Not quite. Chrome extensions present unique challenges that don't exist in traditional web apps:

This guide shows you how to solve each of these problems and ship a monetized extension.

The Architecture You Need

A Chrome extension with subscriptions requires three components:

1. Your Extension: The Chrome extension itself (popup, content scripts, background service worker)

2. A Backend API: Handles authentication, subscription validation, and license checks

3. A Payment Flow: Stripe Checkout or similar for collecting payments

The extension talks to your backend. The backend talks to your payment provider. The extension never handles payment directly.

Step 1: Set Up Authentication

Before you can charge users, you need to know who they are. The cleanest approach is magic link authentication:

1. User enters email in your extension popup

2. Extension calls your API to send a magic link

3. User clicks link, lands on your web page

4. Web page exchanges token for a session

5. Session is stored in extension storage

This keeps sensitive auth logic on your server while giving the extension a secure session token.

Why magic links? No passwords to store, works great across devices, and users already expect this flow from modern apps.

Step 2: Create Your Subscription Plans

Define what you're selling. For a Chrome extension, common models include:

Set up your plans in your billing system with clear entitlements. For example:

Step 3: Implement the Checkout Flow

When a user clicks "Upgrade to Pro" in your extension:

1. Extension calls your API: POST /checkout/session

2. API creates a Stripe Checkout session with the user's email

3. API returns the checkout URL

4. Extension opens the URL in a new tab

The user completes payment on Stripe's hosted checkout page. Stripe sends a webhook to your backend. Your backend updates the subscription status.

Important: Never embed payment forms in your extension. Always redirect to a hosted checkout page. This keeps you PCI compliant and avoids Chrome Web Store policy issues.

Step 4: Validate Subscriptions in the Extension

Every time your extension needs to check if a user has access to a paid feature:

1. Extension calls your API: GET /subscriptions/current

2. API returns the subscription status and entitlements

3. Extension caches the result (with a reasonable TTL)

4. Extension enables/disables features based on entitlements

Caching strategy: Check the subscription on extension load and every 5-15 minutes. Don't hit your API on every user action.

Step 5: Handle Edge Cases

Real-world extensions need to handle:

Subscription expired: Show a gentle upgrade prompt, not a hard block. Give users a day or two of grace.

Payment failed: The subscription enters "past_due" status. Notify the user but don't immediately cut access. Learn more about handling failed payments in our guide on subscription lifecycle management.

Offline usage: Cache the subscription status. If the user is offline, trust the cached status for a reasonable period (24-48 hours).

Multiple devices: Subscriptions should be per-user, not per-device. Store the session token securely and sync status across the user's browsers.

The Code: A Minimal Implementation

Here's what the extension-side code looks like:

// background.js (service worker)

async function checkSubscription() {

const { sessionToken } = await chrome.storage.local.get('sessionToken');

if (!sessionToken) return { status: 'none' };

const response = await fetch('https://api.yourapp.com/v1/subscriptions/current', {

headers: { 'Authorization': `Bearer ${sessionToken}` }

});

const subscription = await response.json();

await chrome.storage.local.set({ subscription });

return subscription;

}

// popup.js

async function upgradeClicked() {

const { sessionToken } = await chrome.storage.local.get('sessionToken');

const response = await fetch('https://api.yourapp.com/v1/checkout/session', {

method: 'POST',

headers: {

'Authorization': `Bearer ${sessionToken}`,

'Content-Type': 'application/json'

},

body: JSON.stringify({ planId: 'pro_monthly' })

});

const { url } = await response.json();

chrome.tabs.create({ url });

}

Why StackBE Makes This Easier

Building all of this from scratch means writing:

StackBE provides all of this out of the box. One API for auth, billing, and entitlements.

Instead of building and maintaining subscription infrastructure, you can focus on what makes your extension valuable.

As we've discussed in why billing doesn't belong in your core app, separating subscription logic from your product code leads to faster shipping and fewer bugs.

Next Steps

1. Sign up for StackBE and create your first app

2. Define your products and plans

3. Integrate the SDK into your extension

4. Launch and start earning

Your extension is ready to make money. The infrastructure shouldn't be what holds you back.