# Main Domain Cookie

With JENTIS, you can easily capture complete user journeys across all your subdomains. The **Main Domain Cookie** feature allows you to configure whether first-party identifiers (f.e. JENTIS User-ID) are implemented at your website’s main domain or subdomain level in your containers. With just one click, all data can be shared across the main domain and all its subdomains, ensuring consistent user sessions, unified tracking, and a clearer understanding of how users engage with your entire digital ecosystem.

In this article, we’ll explain how to configure this when creating or editing a container, how to verify if the JENTIS cookie is set on your main domain or subdomain, and how to configure it.


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# 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.jentis.com/key-features/main-domain-cookie.md?ask=<question>
```

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.