About Site Plugin Extensions

With site plugins, you can create interactive and feature-rich components that seamlessly integrate into Wix’s business solutions, such as Wix Stores and Wix Bookings, extending their functionality and user experience.

Wix users can easily place site plugins into predefined slots (UI placeholders) within Wix apps, using the plugin explorer available in all Wix editors.

Terminology

The following are key terms related to site plugins:

Term	Definition
Host widget	A widget belonging to a Wix business solution, which contains one or more slots.
Slot	A placeholder within a host widget in which users can add a plugin.
Site plugin	A component that can be added inside a slot, extending the host widget's functionality.
Plugin API	An API contract between a site plugin and a slot that both must implement to communicate.

How site plugins work

A site plugin integrates with its host widget in two ways:

• Visually, by embedding its UI inside one of the host's slots
• Logically, by implementing a communication interface with the host

To enable site plugins to communicate with their hosts, each slot supports an API that provides data about the plugin's context (for example the productId of the current product on the Product page).

Slots and plugin APIs

Wix offers a range of placeholders – called slots – across app pages, for which you can build plugins.

When developing a plugin, you need to explicitly declare the specific slots in which users are allowed to add it.

Explore the slots available on each host widget, as well as the APIs they support:

Wix app	Host widget
Wix eComm	Checkout page
Wix Stores	Product page
Wix Stores	Category page
Wix Stores	Shop page
Wix Stores	Gallery widget
Wix Bookings	Service page
Wix Events	Event Details page
Wix Blog	Post page

Implementation options

You can add a site plugin extension using:

• Wix Blocks: Create a site widget in Wix's native app editor. Design your site plugin using visual layout and design tools, and code your business logic using Velo, Wix’s native coding solution.
• Wix CLI: Create a site plugin using the CLI and custom element technology, with your code by default deployed on our servers. The creation and setup process of your widget takes place in the terminal. Then, to edit your plugin, you write code directly in your CLI app project's files.
• Self-hosted custom element: Create a site plugin using custom element technology, with your code deployed on your own server. The custom element is essentially a new HTML tag that you define, which is made available in the Wix editors as a widget.

Sandboxing in the editor

When rendered in the editor, custom elements are sandboxed to enhance security. This means they're treated as if they come from a different domain, and Wix does not support the allow-same-origin directive in the sandbox attribute. As a result, your site plugin can't access same-origin resources in the editor.

This restriction impacts several key web storage and caching APIs:

• Cookie Store API, such as document.cookie
• Web Storage API, such as Window.localStorage and Window.sessionStorage
• IndexedDB API
• Cache API

To overcome these limitations:

1. Detect the environment with viewMode().
2. When in the editor, mock the storage or modify your API usage accordingly.