Merge Announcement: Plugin Dependencies

Note: This post was updated to add the “Third-party plugins not hosted on The community site where WordPress code is created and shared by the users. This is where you can download the source code for WordPress core, plugins and themes as well as the central location for community conversations and organization.” section. 15th February, 2024 – @costdev

View the kickoff post, the Trac ticket and the feature plugin for PluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the Plugin Directory or can be cost-based plugin from a third-party Dependencies.

Purpose & Goals

Extensibility of WordPress through plugins and the HooksHooks In WordPress theme and development, hooks are functions that can be applied to an action or a Filter in WordPress. Actions are functions performed when a certain event occurs in WordPress. Filters allow you to modify certain functions. Arguments used to hook both filters and actions look the same. APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways. is one of its most beneficial features. There are many plugins that act purely as extensions of others, building functionality on top. The Plugin Dependencies feature aims to make the process of installing/activating addons (dependents) and the plugins they rely on (dependencies) consistent and easy to use.

Plugin authors are currently implementing their own ways of informing users about other plugins that they depend on. The implementations are inconsistent and sometimes incomplete. Users are often left to search for and install the other required plugins themselves.

The feature does not intend to replace the need for defensive coding within dependent plugins, or ensure version compatibility with their dependencies; nor does it seek to mitigate the vast array of potential plugin interactions. For WordPress and/or PHPPHP The web scripting language in which WordPress is primarily architected. WordPress requires PHP 5.6.20 or higher incompatibilities, CoreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. already has handling for preventing installing, updating, or activating plugins with unmet requirements.

Implementation Details

A plugin’s dependencies can be declared by the use of a new Requires Plugins headerHeader The header of your site is typically the first thing people will experience. The masthead or header art located across the top of your page is part of the look and feel of your website. It can influence a visitor’s opinion about your content and you/ your organization’s brand. It may also look different on different screen sizes. in the dependent plugin’s main file. This must contain a comma-separated list of slugs for its dependencies, such as jetpack (jetpack/jetpack.php is not supported). It does not support commas in plugin slugs.


 * Plugin Name: Bridge for Foo and Bar
 * Requires Plugins: foo, bar

Version management support, such as providing specific minimum and maximum version numbers through the Requires Plugins header value, is not currently supported.


Declaring a plugin dependency places the following requirements:

  1. Bridge for Foo and Bar can only be installed once Foo and Bar have been installed.
  2. Bridge for Foo and Bar can only be activated once Foo and Bar have been activated.
  3. Foo and Bar can only be deactivated once Bridge for Foo and Bar has been deactivated.
  4. Foo and Bar can only be deleted once Bridge for Foo and Bar has been deleted.

Viewing, installing and activating dependencies

In the Plugins > Add New screen, dependencies are listed in the dependent’s plugin card. Next to these is a View Details link to open a dependency’s information modal. The dependency can be installed and activated using the buttons in the modal’s footer.

Previously, the modal would close upon clicking the Install Now or Activate button. The feature makes the modal persistent, and the buttons used in the plugin cards and modal now use the same underlying markup and functionality for consistency and reduced maintenance burden.

The side effect of this shared functionality is that automatic redirection upon activating a plugin from Plugins > Add New is no longer available. This has the benefit of not redirecting a user away from the Plugins > Add New screen for each plugin, removing them from their current context. Users can therefore install and activate multiple plugins without leaving their current context.

For plugins with onboarding experiences, they often have additional logic in case a plugin is installed and activated through a tool such as WP-CLIWP-CLI WP-CLI is the Command Line Interface for WordPress, used to do administrative and development tasks in a programmatic way. The project page is, so that the user is still presented with the onboarding experience upon navigating to a screen deemed an appropriate starting place.

Automatic deactivation of dependent plugins

As currently implemented, plugins with unmet dependencies are automatically deactivated. While this was the approach suggested in initial discussions, there were valid concerns raised about this behavior after merging into trunk. These have been weighed and discussed, and a decision was made to remove this behavior.

Third-party plugins not hosted on

Defining plugins not hosted on as dependencies will enforce and display the dependencies to the user. However, there will be no ability to install the missing plugins through the UIUI User interface changes, and these will need to be installed manually.

UI changes

The feature makes changes to the UI on two screens: Plugins > Installed plugins, and Plugins > Add New.

Design Feedback

Design feedback was requested on the ticketticket Created for both bug reports and feature development on the bug tracker. and responses were received from @azaozz, @paaljoachim and @karmatosed on the ticket and on the Feature Plugin repository.

Plugins > Installed plugins

The following changes are made:

  1. Dependent plugin rows now contain a list of their dependencies, linked to the respective plugin modal to install and activate the dependency.
  2. Dependency plugin rows now contain a list of their dependents.
  3. If a plugin has dependencies that are not installed and active, the Activate link is disabled.
  4. If a plugin has dependents that are active, the Deactivate and Delete links are disabled.


Plugin rows without listing any dependents or dependencies.
No dependents or dependencies are listed.


Plugin rows for a dependent and its two dependencies. The plugin row for a dependency shows a list of plugins that depend on it, and a dependent's plugin row shows a list of plugins that it depends on. The dependent's plugin row links the names of each dependency to a modal with buttons to install and activate the dependency.
Dependents and dependencies are listed, and actions are enabled/disabled based on the status of requirements.

Plugins > Add New

The following changes are made:

  1. If a plugin has unmet dependencies, the Install Now and Activate buttons are disabled, both in their plugin card and their plugin information modal.
  2. Dependent plugin cards now contain a notice listing their dependencies, with a View Details link to the dependency’s information modal which contains Install Now or Activate buttons based on their current installation status.
  3. Plugin information modals are now persistent after button clicks, and modal-based plugin installation and activation are now performed through AJAX directly within the modal.


A plugin card that does not list dependencies for the plugin, and allows installation even if the dependencies are not installed first.
Plugin card with no dependencies listed and an active Install Now button despite unmet dependencies.


A plugin card with a notice containing a list of dependencies and a link to open a modal with buttons to install and activate the dependency
Plugin card with dependencies listed with modal links to install and activate each dependency, and the “Install Now” button disabled while dependencies are unmet.

User Testing

The feature team released calls for testing in October 2022 and March 2023. Additional user testing was performed during design and technical feedback with reports on the ticket and in the #core-upgrade-install SlackSlack Slack is a Collaborative Group Chat Platform The WordPress community has its own Slack Channel at channel up to the day of commit.


Based on responses to calls for testing, and design and technical feedback, the following UI changes were made:

  1. Adminadmin (and super admin) notices for each unmet dependency were reduced to a single notice informing the user that there were plugins with unmet dependencies.
  2. A dedicated Dependencies tab was removed from the Plugins > Add New screen in favour of an integrated solution in plugin rows on Plugins > Installed plugins and plugin cards on Plugins > Add New.
  3. The plugin row on Plugins > Installed plugins had a Manage Dependencies action link removed, which linked to the removed Dependencies tab.
  4. Messaging was improved to inform the user about missing dependencies.


A security review was performed by @costdev during the development of the feature following WordPress security best practices of escaping output, sanitizing input (slugs, POST, etc.), verifying AJAX referrers and using nonces where appropriate. Comparisons were also done with existing functionality to avoid missed opportunity for hardening the feature.

AccessibilityAccessibility Accessibility (commonly shortened to a11y) refers to the design of products, devices, services, or environments for people with disabilities. The concept of accessible design ensures both “direct access” (i.e. unassisted) and “indirect access” meaning compatibility with a person’s assistive technology (for example, computer screen readers). (

The feature was reviewed by the team for accessibility concerns. In addition, @costdev reached out to @joedolson regarding the use of links (<a>) as buttons, rather than <button> elements.

It was deemed that this approach, though likely not ideal, is consistent with the patterns throughout the code base today. A wider conversation is needed before a decision can be made about this specific  accessibility pattern at a later date.

wp.a11y.speak() is implemented where appropriate in JavascriptJavaScript JavaScript or JS is an object-oriented computer programming language commonly used to create interactive effects within web browsers. WordPress makes extensive use of JS for a better user experience. While PHP is executed on the server, JS executes within a user’s browser., consistent with prior functionality in Core.

Unit Tests

In addition to user testing, testing by Core developers, and the feature team, unit tests have been written for the feature and the public API is covered. There are plans to continue increasing test coverage during the 6.5 BetaBeta A pre-release of software that is given out to a large group of users to trial under real conditions. Beta versions have gone through alpha testing in-house and are generally fairly close in look, feel and function to the final product; however, design changes often occur as part of the process. period.

Props to @afragen, @pbiron, @azaozz and @desrosj for peer review.

#6-5, #feature-plugins, #feature-projects, #feature-plugin-dependencies, #merge-proposals