Native “Maintenance Mode” with Custom Message and Access Rules

[smahjoob]

Currently, WordPress only has a basic maintenance mode when performing updates, which displays a simple English message:

"Briefly unavailable for scheduled maintenance. Check back in a minute."

There is no control, customization, or management UI for this mode. Everything is handled at the file system level, without any user interface or flexibility.

🔥 Proposed Solution:
We propose adding a native "Maintenance Mode" feature with the following functionality:

Built-in Maintenance Mode UI in the WordPress admin dashboard.

Ability to set a custom message, HTML content, custom CSS, and a contact button.

Rules to allow access only to specific users (e.g., admin, logged-in users, etc.).

Scheduling options for starting and ending the maintenance mode.

A “coming soon” page or customizable message for general visitors.

🔧 Why Not Just a Plugin?
Plugins are not always available when the WordPress core is being updated or in cases of failure.

Plugins may not provide precise control over the load order during updates or maintenance.

Customizing the maintenance page and setting precise rules should be handled in the core, ensuring reliability and performance.

✅ Conclusion:
The maintenance mode in WordPress should go beyond a basic message. We need a fully-featured, secure, and customizable Maintenance Mode directly in the core that is easy to use, reliable, and useful for all types of websites.

Thanks to @audrasjb for reminding me about the Decision, not Option principle.