Upgrading to v12

If you are migrating from WordPress to Altis, check out the migrating guide first.

To upgrade to Altis v12, edit your composer.json and change the version constraint for altis/altis and any local environment modules to ^12.0.0. Note that the new default and recommended version of PHP for Altis v12 is now 8.0. Make sure you have tested your custom code and any additional plugins for compatibility with PHP version 8.0.

	"require": {
		"altis/altis": "^12.0.0"
	"require-dev": {
		"altis/local-server": "^12.0.0"
	"config": {
		"platform": {
			"php": "8.0"

Once you have made these changes run composer update and then run the wp altis migrate command:

# For cloud environments
wp altis migrate

# For local server
composer server cli -- altis migrate

Breaking Changes

PHP 8.0

Altis v12 fully supports PHP 8.0 in both local and cloud environments. Support for earlier versions of PHP has been deprecated and will be removed in future versions. There are plenty of backward incompatible changes in PHP 8.0 which should be addressed. Local Server will also run PHP 8.0 by default unless version 7.4 is explicitly requested.

Refer to our PHP Version Guide for up-to-date compatibility, testing and upgrading information.

Asset Loader

We've updated the humanmade/asset-loader dependency from 0.5.0 to 0.6.1. As part of this change, the following previously deprecated methods in the asset-loader were removed: autoregister, autoenqueue, and register_assets. If your Altis project is using the asset-loader library directly, it is recommended to run a search for these functions across your codebase when upgrading to Altis v12.

Deprecating Local Chassis

We are deprecating and discontinuing support for the Local Chassis development environment in Altis v12. The newer Local Server should be the go-to environment for all Altis development going forward. This means that the require-dev section in the project's composer.json should no longer list altis/local-chassis and should only use altis/local-server instead:

	"require-dev": {
		"altis/local-server": "^12.0.0"

Note that Local Server will not automatically inherit or import any data from existing Chassis environments. Any files or database migrations between development environments will have to be done manually.

Headline Features

Codespaces Support

Altis now has support for GitHub Codespaces, which is a cloud-based development environment directly inside the browser. This makes it possible to quickly launch and work on Altis projects without having to install any of the development tools on your local computer. It also allows you to share preview environments with colleagues.

Visit our complete guide to get started with Altis in Codespaces.