Checkout Links

Integration Overview

Checkout Links allow you to create a URL that instantly creates a SellAuth checkout session when opened. This is the simplest possible integration: no JavaScript, no SDK, no embeds, no custom logic. You can use these links behind buttons, anchors, images, emails, or ads, and they will open the SellAuth checkout automatically. When a customer opens a Checkout Link:

A checkout session is created server-side
A short loading screen is shown
A background CAPTCHA is solved automatically
The customer is redirected to the SellAuth checkout page

The loading spinner is intentional and required for bot protection.

HTML Integration

All you need to do is create a link or button that points to the Checkout Link URL:

<a
  href="https://<your shop>.mysellauth.com/checkout-link?cart[0][productId]=<product id>&cart[0][variantId]=<variant id>&cart[0][quantity]=<quantity>"
  target="_blank"
>
  <span>Buy Now</span>
</a>

Parameters

`cart` (required)

An array of cart items.

Field	Type	Required	Description
`cart[index].productId`	number	Yes	Product ID
`cart[index].variantId`	number	Yes	Variant ID
`cart[index].quantity`	number	Yes	Quantity (1-100000)
`cart[index].parentVariantId`	number \| null	No	ID of the variant this addon product belongs to

Other Parameters (optional)

Parameter	Type	Required	Description
`currency`	string \| null	No	3-letter currency code
`email`	string \| null	No	Customer email
`affiliate`	string \| null	No	Affiliate / referral code
`utm_source`, `utm_medium`, `utm_campaign`, `utm_term`, `utm_content`	string \| null	No	Campaign attribution stored on the invoice, max 100 characters each. The external referrer host is recorded automatically when the link is opened from another site.

Example with all parameters and multiple cart items

https://<your shop>.mysellauth.com/checkout-link?cart[0][productId]=1&cart[0][variantId]=1&cart[0][quantity]=1&cart[1][productId]=3&cart[1][variantId]=3&cart[1][quantity]=2&cart[1][parentVariantId]=1&currency=USD&email=john.doe@email.com&affiliate=CREATOR123

Need more control (custom items, prefilled details, server-side creation)? See the Checkout API.

Storefront

Integrations

Theming

Localization

Integration Overview

HTML Integration

Parameters

`cart` (required)

Other Parameters (optional)

Example with all parameters and multiple cart items

​Integration Overview

​HTML Integration

​Parameters

​cart (required)

​Other Parameters (optional)

​Example with all parameters and multiple cart items

Integration Overview

HTML Integration

Parameters

`cart` (required)

Other Parameters (optional)

Example with all parameters and multiple cart items