Hosted Checkout

Popup SDK

Open RANTAN Checkout from a browser with the hosted JavaScript SDK.

The Checkout V2 SDK opens a session-specific RANTAN Checkout popup. It is designed for a popup or direct navigation, not iframe embedding.

#Load the hosted SDK

Load the versioned Checkout contract from the RANTAN application domain. It exposes the immutable RantanCheckout global.

HTML

<script src="https://app.rantan.xyz/checkout-v2.js"></script>

#Open a Checkout popup

Call open from a user gesture so browser popup blockers do not reject it. A server-created sessionId is required.

Browser

<button id="buy">Buy with RANTAN</button>
<script src="https://app.rantan.xyz/checkout-v2.js"></script>
<script>
  document.querySelector("#buy").addEventListener("click", async () => {
    const result = await RantanCheckout.open({
      productId: 123,
      sessionId: "c8a9d48e-68b2-48dd-a754-75635cae71d6",
      clientReferenceId: "order_20260730_001",
    });

    // UI notification only. Verify this session from your backend.
    await fetch("/api/orders/20260730_001/verify", { method: "POST" });
  });
</script>

#Options

Option	Required	Description
`productId`	Required	RANTAN product ID bound to the session.
`sessionId`	Required	Server-created Checkout Session UUID.
`clientReferenceId`	Optional	Merchant reference used for an additional browser-side match.
`timeoutMs`	Optional	Wait time in milliseconds. Defaults to 30 minutes and is bounded to 60 minutes.
`closeOnComplete`	Optional	Set false to keep the popup open after completion.
`onComplete / onClose / onTimeout`	Optional	Optional UI callbacks for complete, close, and timeout.

#Build a direct URL

RantanCheckout.url(options) returns the hosted URL without opening a window. Use it for full-page redirects or links.

Hosted URL

https://app.rantan.xyz/checkout/123?session_id=c8a9d48e-68b2-48dd-a754-75635cae71d6

#Completion result

The SDK checks event.origin, popup window identity, protocol version, product, session, and optional client reference before resolving.

postMessage

{
  "type": "rantan:checkout:complete",
  "version": "v2",
  "product_id": 123,
  "purchase_id": "bfaf2aa4-dd86-4356-92db-ae0431806867",
  "status": "completed",
  "client_reference_id": "order_20260730_001",
  "checkout_session_id": "c8a9d48e-68b2-48dd-a754-75635cae71d6"
}

#SDK errors

Code	Description
`CHECKOUT_SESSION_REQUIRED`	No server-created sessionId was provided.
`CHECKOUT_ALREADY_OPEN`	The same Checkout Session is already open.
`CHECKOUT_CLOSED`	The buyer closed the popup before completion.
`CHECKOUT_TIMEOUT`	The bounded wait ended before completion.