Can I sell credits rather than a subscription?

Yes. Credit packs are one-time purchases, and you can run them alongside subscriptions in the same catalogue. Many AI products end up selling both to different segments.

How do I bill for usage above an allowance?

Pay-as-you-go pricing covers metered products, and you can also charge a one-off amount onto a live subscription mid-cycle for an overage or an add-on.

How should my backend grant credits?

On the payment_success webhook, which fires for the first charge and every renewal. Do not fulfil on subscription_created alone — it can arrive while the first payment is still pending.

What about tax when my users are worldwide?

We are the Merchant of Record, so VAT, GST and US sales tax are calculated, collected, remitted and filed under our registrations. You are not registering in the EU or watching US nexus thresholds.

Can my agents call the platform directly?

Yes. Alongside the REST API and CLI there is an MCP server with documented Cursor, Claude and VS Code integration, so an agent can query orders or manage products.

SaaS · AI products

Billing for a product whose costs move with every request.

An AI product has a marginal cost that a normal SaaS does not, an audience that arrives from everywhere at once, and a pricing model that will change twice before the year is out. Credit packs, metered usage and mid-cycle plan changes are all first-class here.

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What AI pricing needs that ordinary billing lacks

001

Packs

Credits, not just seats

Sell a pack of generations as a one-time purchase, or bundle an allowance into a plan and charge for what goes beyond it. Both are ordinary products here, and both settle into the same order stream.

002

Metered

Usage you can charge for

Pay-as-you-go pricing, plus one-off amounts charged onto a live subscription. When a user burns their allowance on day nine, the overage does not have to wait for the next renewal.

003

Flexible

Pricing will change

Model costs drop, competitors move, and the tier that made sense in spring does not in autumn. Plans, offers and intervals are configuration, and moving a customer between them is prorated to the day.

004

Global

Your users are everywhere on day one

AI products get international from the first tweet. Local payment methods, local pricing and the VAT or GST on each charge are handled from the first sale, not after an accountant asks.

Subscription plans with credit allowances and usage-based charges listed alongside monthly recurring revenue. — Plans, allowances and the overage charges on top of them, in one view.

Shipping pricing for an AI product

01
Decide the unit

A credit, a generation, a seat or a month. Whichever it is, model it as a product with offers rather than as code.
02
Put checkout in the app

An overlay opens over your pricing page so nobody leaves mid-upgrade. Embedded works if a modal is wrong for the flow.
03
Grant on the event

Credit the account from the payment webhook, not from the browser redirect. The tab gets closed; the webhook still arrives.
04
Change the pricing later

Add plans, retire offers, move customers with proration. None of it requires a migration or a new integration.

Merchant of Record

You could do all of this yourself

Selling digital goods across borders means registering for tax in each market, wiring up a tax engine, and answering for every dispute. As your Merchant of Record, that is our name on the paperwork instead of yours.

What it takes

Fungies

Processor only

01 Tax registration

✓ None needed — we are already registered.

You register for VAT and sales tax per market.

02 Tax calculation

✓ Real-time rates on every transaction.

You wire up a tax engine and maintain it.

03 Remittance

✓ We file and pay the authorities directly.

You file monthly, quarterly, and annually.

04 Audits

✓ We answer the tax authority.

You keep the records and take the questions.

05 Chargebacks

✓ Disputes and fraud handled for you.

Your team fights each case.

06 Pricing

✓ One commission, only when you sell.

Processor fee plus tax software plus consultants.

07 Accounting

✓ You receive net revenue.

Gross receipts plus a tax liability to track.

The pieces you would otherwise build

Credit packs: One-time purchases at any tier, with the bulk discount expressed as ordinary pricing rather than logic.
Free trials that convert: Start a plan in trial and let it roll over, or end the trial early through the API when someone upgrades.
Entitlements from webhooks: Open access on payment_success and close it on cancellation, so credits follow money rather than a nightly job.
Self-serve upgrades: A branded portal where users change plan, buy more credits or update a card without emailing support.
An API and an MCP server: REST at api.fungies.io/v0, a JavaScript SDK, a CLI, and an MCP server your own agents can call.
Tax on every charge: Calculated for the buyer's country, remitted and filed under our registrations, including on renewals.