> For the complete documentation index, see [llms.txt](https://domainmappingsystem.gitbook.io/domainmappingsystem-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://domainmappingsystem.gitbook.io/domainmappingsystem-docs/features/alias-domain-authentication.md).

# Alias Domain Authentication

In order to allow website visitors to login to user accounts on mapped subdomains of your website, you can simply enable the checkbox for *Alias Domain Authentication:*

<figure><img src="/files/4GcjLhKa7UzQYw2Q2HD0" alt=""><figcaption><p>Alias Domain Authentication Checkbox</p></figcaption></figure>

This will allow users to login to Alias Domains of your website and remain only logged in to that Alias Domain. They are only able to access protected login pages that are mapped to the specified alias.

### Selective Alias Domain Authentication

The dropdown checkbox allows you to selectively activate Alias Domain Authentication only on specific alias domains:&#x20;

<figure><img src="/files/SfDOA9xQs7qCcN08DOTP" alt=""><figcaption><p>Activating Subdomain Authentication on Specific Subdomains</p></figcaption></figure>

### Multisite Requirements

If you are trying to configure Alias Domain Authentication on multisite, you must update the sunrise.php file mentioned in our [multisite integration](/domainmappingsystem-docs/features/multisite-integration.md) docs to change this string from this:

```
if ( ! is_multisite() || $is_admin ) {
    return $site;
}
```

To this:

```
if ( ! is_multisite() || ! $is_admin ) {
    return $site;
}
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://domainmappingsystem.gitbook.io/domainmappingsystem-docs/features/alias-domain-authentication.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.