SellAuth has no crypto gateway plugin, but it has a Custom Payment Method that can redirect buyers to CryptoPayr. Here is the full setup: the redirect URL, the placeholders that matter, auto-confirming orders through the SellAuth API, a test order and the fixes for the three things that usually go wrong.
SellAuth is popular with digital-goods sellers because it is fast to set up and charges nothing per sale. What it does not ship with is a crypto gateway you control. It does ship with a Custom Payment Method that can send the buyer to a URL of your choice — and that is all CryptoPayr needs. Set it up once and your SellAuth shop takes Bitcoin, Ethereum, USDT, USDC, Monero and 110+ other coins at a hosted checkout, with the order confirmed and delivered in SellAuth the moment the payment settles.
The whole thing takes about ten minutes. No plugin, no code, no webhook to write.
Step 4 happens at settlement, not when the buyer reaches a “thank you” page. A buyer who pays and closes the tab still gets their order.
Sign in and open Dashboard → Third-party integrations → SellAuth. Click Enable SellAuth integration. You get a Redirect URL that looks like this:
https://cryptopayr.com/api/v1/sellauth/<your token>?invoice={id}&ref={unique_id}&amount={price}¤cy={currency}&email={email}The token identifies your account. The {…} parts are SellAuth variables — SellAuth replaces them with the real values for every order, so copy the URL exactly, braces included.
That is the whole buyer-side setup. Your shop now offers CryptoPayr at checkout.
Without this step, paid orders show up in your CryptoPayr dashboard as Paid · confirm manually and you process them in SellAuth yourself. With it, nobody touches anything.
The key is stored encrypted and is only ever used for one call per order: GET /v1/shops/{shop_id}/invoices/{id}/process?mark_as_paid=true. If a call fails because SellAuth is briefly unreachable, CryptoPayr retries it on its own for the next hour or so; if it fails for good (a revoked key, a wrong shop id) the order is flagged in your dashboard with the reason and a Retry button.
Buy something cheap from your own shop, pick the crypto method, and pay at the CryptoPayr checkout. Then check three things:
You will also see the payment in Payments, credited to your balance like any other sale, with metadata set to sellauth:<invoice id>:<reference>. If you run a webhook for your other integrations it fires for SellAuth orders too.
SellAuth gives you two identifiers for an order. {unique_id} is the public reference the buyer sees in the checkout URL. {id} is the numeric invoice id, and it is the only value the Process Invoice API accepts. CryptoPayr’s redirect URL carries both — invoice={id} to confirm the order, ref={unique_id} to show the buyer — which is why you must paste it unchanged. A redirect URL that only passes {unique_id} will take payments fine but can never auto-confirm them.
invoice={id} part, or a placeholder was retyped by hand. Copy the URL from the CryptoPayr page again.SellAuth orders are ordinary CryptoPayr payments: the same volume-based processing fee, the same instant credit to your USD balance (or coin balance, on direct settlement), the same payouts and refunds. SellAuth itself takes nothing on a custom payment method beyond whatever fee you configure on it.
Ready? Create a free CryptoPayr account, open Third-party integrations → SellAuth, and your shop takes crypto in the next ten minutes.
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