What's new in 4.0¶

4.0 is stable¶

MageObsidian 4.0 is the first stable release. From here on, the surface listed in the Reference does not change incompatibly until 5.0. What that covers, and how long each line is supported, is in Versioning & support.

Nothing was renamed¶

No package was renamed. The Packagist and npm names are the ones you already use.

4.0.0 shipped the last 2.x and 3.x code plus SPDX license headers. Those headers caused a regression on PHP 8.3 and 8.4, where templates failed. Storefront 4.0.1 fixed it the same day, together with an unrelated bug that left a template variable missing on Magento 2.4.7.

Two release trains¶

The framework and the storefront are versioned separately. Each train versions all of its packages together.

Framework: module-modern-frontend, module-modern-frontend-cli, module-modern-frontend-twig, component-modern-frontend and the npm package mage-obsidian.
Storefront: the storefront modules and theme-base.

The storefront declares the framework line it needs, so a storefront release never installs against a framework it was not built for. See Two release trains.

Where the code lives¶

The framework lives in the mage-obsidian/framework monorepo and the storefront in mage-obsidian/storefront. The per-package repositories are read-only mirrors: open issues and pull requests in the monorepos. theme-default stays in its own repository.

Compatibility¶

Every combination of Magento Open Source and Mage-OS 2.4.7, 2.4.8 and 2.4.9 passed on 2026-10-06, with framework 4.0.0 and storefront 4.0.1. Magento and Mage-OS 2.4.7 is the floor and there is no ceiling: newer releases are expected to work and are added to the table once tested. See the compatibility table.

Upgrading from 3.x¶

The upgrade changes your version constraints and nothing else. Follow Upgrading from 3.x to 4.0.

What is not verified yet¶

Some areas have not been tested to the same depth as the rest. They are listed, with their status, in Known scope.