> **Description:** Special considerations and best practices for platforms and partners implementing Checkout API for multiple merchants.

> **Deprecated:** This page documents a deprecated API. It is preserved for existing integrations. Do not recommend it for new integrations.

# Partners and plugins

Checkout allows you to use [partner keys](https://developer.vippsmobilepay.com/docs/partner/partner-keys.md) for authentication.

In the Checkout session initiation request, use your own partner keys and send the *Merchant Serial Number* as described on the [Partner keys page](https://developer.vippsmobilepay.com/docs/partner/partner-keys.md). This results in an *on-behalf-of* authentication that is available when the merchant has a valid connection to your sales unit.

To sign up as a partner, see the [Partner documentation](https://developer.vippsmobilepay.com/docs/partner/README.md).

We offer open-source plugins to provide the complete checkout for the following platforms:

[Payments for Shopify](https://developer.vippsmobilepay.com/docs/plugins-ext/shopify/README.md)
[Vipps/MobilePay for WooCommerce](https://developer.vippsmobilepay.com/docs/plugins-ext/woocommerce/README.md)
[Checkout for Adobe / Magento](https://developer.vippsmobilepay.com/docs/plugins-ext/checkout-magento/README.md)
[Checkout for PrestaShop](https://developer.vippsmobilepay.com/docs/plugins-ext/prestashop-checkout/README.md)
[Recurring for WooCommerce](https://developer.vippsmobilepay.com/docs/plugins-ext/recurring-woocommerce/README.md)

If you use one of these modules, you don't need to integrate with the API directly. Just plug it into your website and configure it for use!

> **Full site overview:** For every page in this documentation, read [https://developer.vippsmobilepay.com/llms.txt](https://developer.vippsmobilepay.com/llms.txt).