> Portal Navigation:
> 
> - Append `.md` to any URL under `https://dev.wix.com/docs/` to get its markdown version.
> - Pages are either content pages (article or reference text) or menu pages (a list of links to child pages).
> - To get a menu page, truncate any URL to a parent path and append `.md` (e.g. `https://dev.wix.com/docs/sdk.md`, `https://dev.wix.com/docs/sdk/core-modules.md`).
> - Top-level index of all portals: https://dev.wix.com/docs/llms.txt
> - Full concatenated docs: https://dev.wix.com/docs/llms-full.txt

## Resource: About Site Plugins

## Article: About Site Plugins

## Article Link: https://dev.wix.com/docs/site-extensions/site-plugins/about-site-plugins.md

## Article Content:

# About Site Plugins

A [site plugin](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/site-plugins.md) is a custom element that renders in a slot on a widget built by a Wix business solution, such as the Wix eCommerce Checkout page. This reference is the contract for a plugin you add as an extension: the generated files, the configuration object, the custom element that renders in the slot, and the plugin's settings panel.

The file set and configuration object are the same whether you add the plugin in a Studio Two site project or in a Wix CLI app.

## What's in this reference

- [Site Plugin Extension Files and Code](https://dev.wix.com/docs/site-extensions/site-plugins/site-plugin-extension-files-and-code.md): The generated file set, the `extensions.sitePlugin()` configuration fields, the custom element and the slot data it receives, and the settings panel.

The configuration file lists the slots the plugin can fill. For the widgets that have slots, each slot's `placements` values, and the data each slot passes to a plugin, see [About Slots](https://dev.wix.com/docs/build-apps/develop-your-app/extensions/site-extensions/site-plugins/supported-wix-app-pages/about-slots.md).

> **Note:** The screenshots and slot locations in About Slots and its widget pages might not match every Wix editor. In some editors, a widget and its slots might look different, or not exist.

## See also

- [Site Plugins](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/site-plugins.md)
- [Site Plugin Extension Files and Code](https://dev.wix.com/docs/site-extensions/site-plugins/site-plugin-extension-files-and-code.md)
- [About Slots](https://dev.wix.com/docs/build-apps/develop-your-app/extensions/site-extensions/site-plugins/supported-wix-app-pages/about-slots.md)