Launching July 2026 · Join the waitlist

Monetize your extension effortlessly.

ExtensionBill is the modern ExtensionPay alternative with a Merchant of Record built in.

Add payments in a day, not a week. No backend, no tax headaches. Connect your Merchant of Record and start charging.

Works with the MoR you already use

Join the waitlist

We're on the way to release in July 2026. Join now to get early access and be first to charge for your extension, no backend, tax handled.

No spam, just one email the day we launch.

Merchants of Record

Browsers supported

Servers to run

Cut of your revenue

The wedge

One quadrant nobody else fills

Extension developers need two things: a no-backend SDK and a Merchant of Record that handles tax. Every other tool gives you one, not both. ExtensionBill sits in the corner where both are true.

You are here

No-backend SDK Tax handled (MoR)

ExtensionBill

Drop-in SDK and the tax handled.

Build the glue yourself Tax handled (MoR)

Polar, Creem, Dodo, Paddle, Lemon Squeezy

Tax handled, but you build and host the backend glue.

No-backend SDK You handle the tax

ExtPay, Addon Pay

No backend, but you still owe the global tax.

Build the glue yourself You handle the tax

Raw Stripe

Build everything yourself, and owe the tax too.

Bring the MoR you already use

Connect any supported Merchant of Record. Switch whenever you like.

Everything you need to charge for your extension

A complete payment integration for your extension: a hosted verification layer and a drop-in SDK. You keep your Merchant of Record, your pricing, and your payouts.

Zero backend

ExtensionBill's hosted layer verifies payments straight from your extension. No server to provision, no API to babysit, no infrastructure bill.

Your extension ExtensionBill verifies Your MoR

Bring your own MoR

Connect Polar, Paddle, Lemon Squeezy, Creem, or Dodo Payments. Your MoR is the seller of record, so it collects and remits tax. You own pricing and payouts.

Drop-in SDK

One import and a few lines. Add it to a new extension, or migrate an existing one in minutes.

Familiar, modern API

A clean, well-typed SDK that covers everything ExtPay does. Migrate an existing extension in minutes, and the tax is suddenly handled.

Instant unlock

The moment a user pays, premium features unlock. No polling, no webhooks to wire up.

Always current with your MoR

When a Merchant of Record changes its API, we update the integration for you. You never chase a breaking change or ship an extension update just to stay compatible.

Flat fee, no revenue cut

Pick a package and pay one flat monthly fee, whatever you earn. ExtensionBill never takes a percentage or per-sale cut, so your cost stays the same as your revenue grows.

Any revenue, $0 cut from us. Just your flat package fee.

Monetize any kind of extension

However your extension makes money, ExtensionBill handles the payment layer.

AI-powered tools

Charge per month or per seat for GPT wrappers, writing assistants, and research copilots. Gate the model behind a paid check.

Productivity & utilities

Sell a Pro tier for power features: bulk actions, exports, automations, and deeper integrations.

One-time Pro unlock

Offer a lifetime unlock for premium features with a single payment, no subscription to manage.

Subscriptions & trials

Run free trials and recurring plans through your MoR. ExtensionBill checks status on every launch.

From zero to paid in three steps

No backend to build, no webhooks to host. Connect, drop in, charge.

Connect your MoR

Connected

Payouts go straight to you

Drop in the SDK

Add one import and a couple of lines. ExtensionBill's hosted layer handles verification for you.

popup.js

// Gate a premium feature
const user = await extpay.getUser()
if (user.paid) showProFeatures()

Get paid

Users check out through your MoR, which applies the right tax at their location. Access unlocks instantly.

Pro plan $5/ mo

Paid Premium unlocked instantly

Add payments in a few lines

Install the SDK, point it at your Merchant of Record, and ship.

Install

$ npm install extensionbill

Join the waitlist See how it works

Works in Chrome, Firefox, and Edge.

Integrate

popup.js

// Open checkout, then unlock once the user has paid
import ExtensionBill from 'extensionbill'
const extpay = ExtensionBill('your-extension-id')
 
upgradeBtn.onclick = () => extpay.openCheckout()
 
const { paid } = await extpay.getUser()
if (paid) enableProMode()

Coming from ExtPay?

Coming from ExtPay? Migrate in minutes.

ExtensionBill's SDK covers the same jobs as ExtPay with a cleaner, modern API. A short, mechanical migration, and you gain a Merchant of Record that handles tax for you.

Same concepts: getUser(), checkout, paid events
A short, mechanical rename, mapped by the migration guide
Gain worldwide MoR tax compliance instantly

Join the waitlist

background.js

// Familiar concepts, cleaner API, tax handled.
import ExtensionBill from 'extensionbill'
// renamed from ExtPay
 
const extpay = ExtensionBill('your-extension-id')
const user = await extpay.getUser()
 
if (user.paid) unlockPremiumFeatures()
else extpay.openCheckout()

How ExtensionBill compares

ExtPay gives you a no-backend SDK but leaves you the tax. A raw Merchant of Record handles tax but leaves you the backend. ExtensionBill is the only one that does both.

What you need	ExtPay	Raw MoR	ExtensionBill
No-backend SDK	Yes	Build it yourself	Yes
Merchant of Record (VAT, GST, tax)	You owe the tax	Yes	Yes
Typed, modern SDK	Plain JS	No SDK	TypeScript-first
What it costs you	5% of revenue	~4% + your dev time	Flat monthly fee
Cross-browser (Chrome, Firefox, Edge)	Yes	Do it yourself	Yes
Switch providers anytime	Stripe only	Locked per provider	Any MoR

Secure by architecture

ExtensionBill removes whole categories of risk by keeping payment data and servers out of your hands.

No backend, no breach

There's no server for you to run, so there's no server of yours to attack. Verification is hosted, hardened, and maintained for you.

Tax handled by your MoR

Your Merchant of Record collects and remits VAT, GST, and sales tax at each customer's location, and owns PCI compliance. None of it ever touches your extension.

You own the money

Payouts land in your MoR account and the customer relationship stays yours. ExtensionBill never touches the funds.

No lock-in

Switch Merchants of Record whenever you like. The SDK is provider-agnostic, so your code stays portable.

Flat pricing. Not 5% of your revenue.

ExtPay-style tools take 5% forever. ExtensionBill charges a flat monthly fee, whatever you earn. A $5k/mo extension pays a 5% cutter $250 every month. With ExtensionBill it stays flat.

Demo pricing, could be changed

Free

$0 / mo

1 extension, to get started

1 extension
All 5 Merchants of Record
TypeScript-first SDK
Hosted payment verification
Community support

Join the waitlist

Starter

$19 / mo

Up to 3 extensions

Up to 3 extensions
Everything in Free
Email support

Join the waitlist

Growth

$49 / mo

Up to 10 extensions

Up to 10 extensions
Everything in Starter
Priority support

Join the waitlist

Scale

$99 / mo

Unlimited extensions

Unlimited extensions
Everything in Growth
Priority support

Join the waitlist

No cut of your revenue, ever. You also pay your Merchant of Record's standard transaction fees, the ones you already agreed to.

Questions, answered

What developers usually ask before integrating.

Do I really not need a backend?

Right. ExtensionBill hosts the verification layer. Your extension calls the SDK and we confirm payment status against your MoR. There's no server for you to run or maintain.

Which Merchants of Record are supported?

Polar, Paddle, Lemon Squeezy, Creem, and Dodo Payments. Each one handles checkout, tax, and payouts. You can switch between them without touching your extension code.

How much does ExtensionBill cost?

ExtensionBill charges a flat monthly fee, from free up to $99/mo based on how many extensions you run. Unlike ExtPay-style tools, we never take a percentage of your revenue. You also pay your MoR's standard transaction fees, which you already agreed to.

Can I migrate from the original ExtPay?

Yes. ExtensionBill covers the same jobs as ExtPay with a cleaner, modern API. Migrating an existing extension is a short, mechanical rename (the migration guide maps each call). New projects integrate the same way.

How are payments verified?

When a user opens your extension, the SDK asks ExtensionBill whether they've paid. We check with your MoR and return the status, so premium features unlock instantly with no webhooks to host.

Can I switch MoRs later?

Anytime. Your MoR is a connection, not a lock-in. Re-link a different provider and your extension keeps working.

Who handles VAT and sales tax?

Your Merchant of Record does. It acts as the seller of record, collecting and remitting VAT, GST, and sales tax at the buyer's location worldwide. ExtensionBill never touches tax, and neither do you.

Be first when we launch

ExtensionBill opens in July 2026. Join the waitlist for early access: bring your Merchant of Record, drop in the SDK, and start charging with the tax handled, for a flat fee.

Join the waitlist See pricing