Release management notes#

This chapter describes how maintainers manage the releases of Volto.

See also

Read the Plone Release Schedule for details of how Volto's release management works in Plone.

Definition of breaking#

A breaking change refers to a modification, enhancement, or update made to Volto's code base that has the potential to disrupt or "break" an existing Volto-based project's functionality, tests, or customizations.

Breaking changes typically require users or contributors to update their code base, configurations, or customizations of their Volto projects to accommodate the new changes, as they may no longer be compatible with the updated Volto version.

It is essential for maintainers to communicate and document breaking changes clearly to help users and collaborators understand the impact and take appropriate actions to adapt to the new version of the project. This is why Volto's Upgrade Guide exists.

We define a Public API and a Private API to classify the types of changes in Volto.

Public API#

The public API is composed of the following Volto components:

  • Public Components (./src/components/theme)

  • Current list of default blocks included in Volto

  • Volto helpers (./src/helpers)

DOM structure and default styling#

Any change to the Document Object Model (DOM) structure of any Volto component that renders HTML is considered a breaking change. This is because Volto projects rely on the DOM of the stable version for styling and look and feel customizations.

The removal of any property or tag is also considered a breaking change. This especially includes className props that would cause existing CSS to fail.

The addition of DOM elements is also considered a breaking change, because it could result in delivering unstyled or uncustomized content in a Volto project.


It is not considered a breaking change when the change to the DOM is the addition or introduction of a property, such as the addition of a class name to a component or tag.

Private API#

The private API is everything that is considered "internal" to Volto, and it is intended only to be used by Volto itself. Therefore, changes to the private API are non-breaking changes.

The following Volto components are considered private API:

  • CMS user interface fundamental components (./src/components/manage)

  • CMS user interface control panels

  • Libraries used by Volto


In general, the CMS user interface is not considered public API, but is private API, because the customization or modification in a project is not usual, and the overall experience is tied to these components. Thus we give preference to maintaining a good user experience over not backporting changes that could be breaking to the product but could be beneficial for the vast majority of use cases.

For example, if a bug is fixed in the CMS user interface and it would be declared as breaking, it would never get backported to older versions. Similarly for a useful improvement to any CMS user interface feature, or a new feature, they would never get backported to older versions.


If there is a change in the CMS user interface that implies either a change of behavior or change of markup that improves the overall user experience, it's a non-breaking change. It will be properly identified in the Volto Release Notes as a minor change.

Any change to a control panel is a non-breaking change.

If a bug is found in the text block, and the solution involves an upgrade of the Slate library, then it is a non-breaking change. This is true, even if that upgrade implies a breaking change in itself.