# Customer subscriptions Customer subscriptions are simple resources that you can use to track newsletter registrations. Populate the reference with any key that makes sense to your business domain. Send the subscriptions to any third party tool or CRM for marketing and segmentation. Let the customers manage their active subscriptions through their reserved area. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.commercelayer.io/core-api-reference/customer_subscriptions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.