Developers

Add payments to your site in minutes

One script tag. One function call. Cards, bank, and USDC crypto payments, all from a single checkout overlay that works on any website or platform.

How it works

SaturnShift runs as a checkout overlay on your existing site. You keep your design, your flow, your cart.

Load one script tag in your page head

Add a payment button anywhere on your page

Call SaturnShift.checkout() on button click

Customer pays and gets redirected to your confirmation page

What you can integrate

The checkout widget is one piece. SaturnShift also gives you hosted payment pages, invoicing, and a real-time merchant dashboard.

JS snippet

Checkout Widget

Embed a payment button on any page. Opens a secure overlay — no redirect, no custom UI to build.

No-code

Payment Links

Generate shareable payment links from your dashboard. No code required. Useful for invoicing, email, or SMS.

Real-time

Merchant Dashboard

Track every transaction in real time. View payment status, networks used, amounts, and export reports. No backend code needed.

The checkout experience

What your customers see

When a customer clicks your payment button, the SaturnShift checkout loads as a secure overlay. No redirects. No new tabs. They stay on your page.

Integration guide

Select your platform.

Step 1. Load the SaturnShift script

Paste this just before the closing </head> tag in your HTML file.

<script src="https://api.saturnshift.io/checkout.js"></script>

Step 2. Add a payment button

Place this where you want the button on your page. You can style it however you like.

<button id="payBtn">Pay Now</button>

This runs alongside your existing checkout — it does not replace it.

Step 3. Initialize the checkout

Paste this inside a script tag at the bottom of your HTML file, just before the closing </body> tag.

SaturnShift.checkout({
  publicKey: "YOUR_PUBLIC_KEY",
  amount: 49.00,
  currency: "USD",
  title: "Pro Plan",
  description: "Monthly subscription",
  externalReference: "order_" + Date.now(),
  idempotencyKey: "order_" + Date.now(),
  redirectUrl: "https://yoursite.com/thank-you",
  openInNewTab: false,
  allowCard: true,
  allowBank: true,
  allowCrypto: true
}, "#payBtn");

Replace YOUR_PUBLIC_KEY with your actual public key from your dashboard. Use a unique value per order for externalReference and idempotencyKey.

Checkout parameters

Full reference for the SaturnShift.checkout() function.

Parameter	Type	Required	Description
`publicKey`	`string`	Yes	Your merchant public key from the Developers page in your dashboard.
`amount`	`number`	Yes	The payment amount in USD.
`currency`	`string`	Yes	Currency code. Currently only "USD" is supported.
`title`	`string`	Yes	Product or service name shown to the customer.
`description`	`string`	No	Optional description shown in the checkout overlay.
`externalReference`	`string`	Yes	Your internal order or invoice ID. Used for reconciliation.
`idempotencyKey`	`string`	Yes	Unique key per transaction to prevent duplicate charges. Use your order ID.
`redirectUrl`	`string`	Yes	URL the customer is redirected to after a successful payment.
`openInNewTab`	`boolean`	No	Opens the checkout in a new browser tab instead of an overlay. Default: false.
`allowCard`	`boolean`	No	Enable card payments in the checkout. Default: true.
`allowBank`	`boolean`	No	Enable ACH bank payments in the checkout. Default: false.
`allowCrypto`	`boolean`	No	Enable USDC crypto payments in the checkout. Default: true.

Crypto supported on

Ethereum

Base

Polygon

Arbitrum

Payments on any network are automatically bridged and settled to BASE.