Purchase links

A purchase link (buy link) is a URL on usethatapp.com that runs the entire hosted checkout for one price of your app: identity, payment via Stripe, tax, receipt — then returns the buyer to your app. UseThatApp is the merchant of record: it processes the payment, calculates and remits applicable tax, handles refunds and chargebacks, and appears on the buyer's card statement. You get payouts via Stripe.

URL anatomy

https://www.usethatapp.com/buy/{price_id}/?next=...&ref=...&email=...

{price_id} is the opaque public price identifier (prefix prc_). Don't construct it — get it from the Pricing API, where every price also carries a ready-made buy_url you can use directly.

The SDK builds these links for you — purchase_url / purchaseUrl is a pure URL builder: no network call, no configuration needed (an empty price id raises Python ValueError / JavaScript UtaError):

from usethatapp import purchase_url

purchase_url("<prc-price-id>",
             next="https://yourapp.com/welcome",
             ref="partner42",
             email="buyer@example.com")

import { purchaseUrl } from "usethatapp";

purchaseUrl("<prc-price-id>", {
  next: "https://yourapp.com/welcome",
  ref: "partner42",
  email: "buyer@example.com",
});

Query parameters

What the buyer sees

1. Identify. Email, country, and ZIP on one page. An email that matches an existing account is sent through normal sign-in (including MFA). A new email gets an account auto-created — no password, no verification wall in the purchase path.
2. Pay. Card entry via Stripe.
3. Confirm. A confirmation page, then the charge.
4. Return. A success page (with a "resend receipt email" button), then the redirect to next or your Login URL. The license is created synchronously during checkout, so the entitlement is live the moment the buyer returns — no webhook lag, no polling.

The receipt email

The post-purchase email contains:

• the receipt,
• an email-verification link,
• a set-a-password link (for auto-created accounts), and
• a manage link for the subscription.

Already-licensed buyers

A buyer who already has an active license for your app and hits a buy link is never double-charged — they're recognized and sent straight back to your app.

Where buyers can purchase

Purchases are open to buyers in the United States, the European Union, Canada, Australia and the other countries offered at checkout. The buyer's country is enforced on both the declared tax address (country + postal code at identify) and the card's billing address at confirmation. UseThatApp is the merchant of record, so tax is calculated and remitted for you: EU buyers see VAT-inclusive prices, and an EU business can enter its VAT number at identify (or on its UseThatApp profile) to be invoiced net under the reverse charge.

Manage links

The companion to a buy link: the buyer's subscription-management page scoped to your app (upgrade, auto-renew, Stripe billing portal). client_id is your app's public OAuth client id from the dashboard's Integration page; next is validated the same way as above and becomes the "Back to your app" button.

https://www.usethatapp.com/manage/{client_id}/?next=https://yourapp.com/account

Or build it with the SDK — manage_url(next=…) / manageUrl({ next }) — also pure, needing only UTA_CLIENT_ID (Python raises UtaConfigError without it).

Next steps

Get your price ids and ready-made buy URLs from the Pricing API, walk the end-to-end story in Sell from your own website, then test your purchase flow.