# Merchant Center Custom App Integration Guide

Worldline Configuration page is integrated with Commercetools as a Merchant Center Custom App. Once integrated, it can be accessed from a link in the left navigation in Merchant Center. More on Custom Applications could be found here: [https://docs.commercetools.com/merchant-center/managing-custom-applications](https://docs.commercetools.com/merchant-center/managing-custom-applications)

The Worldline configuration is saved as a Custom Object with container 'worldline-configuration'. Within the container, each store will have it's own configuration. The web and cron modules fetch the custom object for their operations. Those applications cache the configuration in Redis to avoid fetching it again. When the configuration changes, the cache is automatically cleared.