Wix Site Plugin Builder

Creates site plugin extensions for Wix CLI applications. Site plugins are custom elements that integrate into predefined slots within Wix business solutions (like Wix Stores, Wix Bookings), extending their functionality and user experience.

Site owners can place site plugins into UI slots using the plugin explorer in Wix editors.

Quick Start Checklist

Follow these steps in order when creating a site plugin:

1. [ ] Create plugin folder: src/extensions/site/plugins/<plugin-name>/
2. [ ] Create <plugin>.tsx extending HTMLElement with observedAttributes
3. [ ] Create <plugin>.panel.tsx with WDS components and widget.getProp/setProp
4. [ ] Create <plugin>.extension.ts with extensions.sitePlugin() and unique UUID
5. [ ] Update src/extensions.ts to import and use the new extension
6. [ ] Run npx tsc --noEmit to verify TypeScript compiles
7. [ ] Run npx wix build and npx wix preview to test
8. [ ] Verify plugin appears in plugin explorer for target slots

Architecture

Site plugins consist of three required files:

1. Plugin Component (<plugin-name>.tsx)

Custom element component that renders in the slot using native HTMLElement:

• Extend HTMLElement class
• Define observedAttributes for reactive properties
• Implement connectedCallback() and attributeChangedCallback() for rendering
• Use inline styles via template strings
• Attributes use kebab-case (e.g., display-name)

2. Settings Panel (<plugin-name>.panel.tsx)

Settings panel shown in the Wix Editor sidebar:

• Uses Wix Design System components (see WDS-COMPONENTS.md)
• Manages plugin properties via @wix/editor widget API
• Loads initial values with widget.getProp('kebab-case-name')
• Updates properties with widget.setProp('kebab-case-name', value)
• Wrapped in WixDesignSystemProvider > SidePanel > SidePanel.Content

3. Extension Configuration (<plugin-name>.extension.ts)

Defines the plugin's placement configuration:

• Specifies which slots the plugin can be added to
• Configures auto-add behavior on app installation
• Sets the tag name and file paths

Plugin Component Pattern

Site plugins use native HTMLElement custom elements:

// my-site-plugin.tsx
class MyElement extends HTMLElement {
  static get observedAttributes() {
    return ['display-name'];
  }

  constructor() {
    super();
  }

  connectedCallback() {
    this.render();
  }

  attributeChangedCallback() {
    this.render();
  }

  render() {
    const displayName = this.getAttribute('display-name') || "Your Plugin's Title";

    this.innerHTML = `
      <div style="font-size: 16px; padding: 16px; border: 1px solid #ccc; border-radius: 8px; margin: 16px;">
        <h2>${displayName}</h2>
        <hr />
        <p>
          This is a Site Plugin generated by Wix CLI.<br />
          Edit your element's code to change this text.
        </p>
      </div>
    `;
  }
}

export default MyElement;

Key Points:

• Extend HTMLElement class directly
• Define observedAttributes static getter to list reactive attributes
• Attributes use kebab-case (e.g., display-name, bg-color)
• Implement connectedCallback() for initial render
• Implement attributeChangedCallback() to re-render when attributes change
• Use inline styles via template strings
• Use this.getAttribute('attribute-name') to read attribute values

Settings Panel Pattern

// my-site-plugin.panel.tsx
import React, { type FC, useState, useEffect, useCallback } from 'react';
import { widget } from '@wix/editor';
import {
  SidePanel,
  WixDesignSystemProvider,
  Input,
  FormField,
} from '@wix/design-system';
import '@wix/design-system/styles.global.css';

const Panel: FC = () => {
  const [displayName, setDisplayName] = useState<string>('');

  useEffect(() => {
    widget.getProp('display-name')
      .then(displayName => setDisplayName(displayName || "Your Plugin's Title"))
      .catch(error => console.error('Failed to fetch display-name:', error));
  }, [setDisplayName]);

  const handleDisplayNameChange = useCallback((event: React.ChangeEvent<HTMLInputElement>) => {
    const newDisplayName = event.target.value;
    setDisplayName(newDisplayName);
    widget.setProp('display-name', newDisplayName);
  }, [setDisplayName]);

  return (
    <WixDesignSystemProvider>
      <SidePanel width="300" height="100vh">
        <SidePanel.Content noPadding stretchVertically>
          <SidePanel.Field>
            <FormField label="Display Name">
              <Input
                type="text"
                value={displayName}
                onChange={handleDisplayNameChange}
                aria-label="Display Name"
              />
            </FormField>
          </SidePanel.Field>
        </SidePanel.Content>
      </SidePanel>
    </WixDesignSystemProvider>
  );
};

export default Panel;

Key Points:

• Prop names in widget.getProp() and widget.setProp() use kebab-case (e.g., "display-name")
• Always update both local state AND widget prop in onChange handlers
• Wrap content in WixDesignSystemProvider > SidePanel > SidePanel.Content
• Use WDS components from @wix/design-system
• Import @wix/design-system/styles.global.css for styles
• Include aria-label for accessibility

Attribute Naming Convention

Site plugins use kebab-case consistently for HTML attributes:

File	Convention	Example
<plugin>.tsx (getAttribute)	kebab-case	this.getAttribute('display-name')
<plugin>.tsx (observedAttributes)	kebab-case	['display-name', 'bg-color']
<plugin>.panel.tsx (widget API)	kebab-case	widget.getProp('display-name')

Output Structure

Site plugins live under src/extensions/site/plugins. Each plugin has its own folder with files named after the plugin.

src/extensions/site/plugins/
└── {plugin-name}/
    ├── {plugin-name}.tsx           # Main plugin component (HTMLElement)
    ├── {plugin-name}.panel.tsx     # Settings panel component
    └── {plugin-name}.extension.ts  # Extension registration
public/
└── {plugin-name}-logo.svg          # Plugin logo (optional)

References

Topic	Reference
Complete Examples	EXAMPLES.md
Slots (App IDs, multiple placements, finding slots)	SLOTS.md
WDS Components	WDS-COMPONENTS.md

Available Slots

Site plugins integrate into predefined slots in Wix business solutions. Each slot is identified by:

• appDefinitionId: The ID of the Wix app (e.g., Stores, Bookings)
• widgetId: The ID of the page containing the slot
• slotId: The specific slot identifier

Common placement areas include product pages (Wix Stores), booking pages (Wix Bookings), service pages, and event pages.

For supported pages, common Wix App IDs, and how to find slot IDs, see SLOTS.md.

Extension Registration

Extension registration is MANDATORY and has TWO required steps.

Step 1: Create Plugin-Specific Extension File

Each site plugin requires an extension file in its folder:

// my-site-plugin.extension.ts
import { extensions } from '@wix/astro/builders';

export default extensions.sitePlugin({
  id: '{{GENERATE_UUID}}',
  name: 'My Site Plugin',
  marketData: {
    name: 'My Site Plugin',
    description: 'Marketing Description',
    logoUrl: '{{BASE_URL}}/my-site-plugin-logo.svg',
  },
  placements: [{
    appDefinitionId: 'a0c68605-c2e7-4c8d-9ea1-767f9770e087',
    widgetId: '6a25b678-53ec-4b37-a190-65fcd1ca1a63',
    slotId: 'product-page-details-6',
  }],
  installation: { autoAdd: true },
  tagName: 'my-site-plugin',
  element: './extensions/site/plugins/my-site-plugin/my-site-plugin.tsx',
  settings: './extensions/site/plugins/my-site-plugin/my-site-plugin.panel.tsx',
});

CRITICAL: UUID Generation

The id must be a unique, static UUID v4 string. Generate a fresh UUID for each extension - do NOT use randomUUID() or copy UUIDs from examples. Replace {{GENERATE_UUID}} with a freshly generated UUID like "95a28afd-7df1-4e09-9ec1-ce710b0389a0".

Property	Type	Description
id	string	Unique static UUID v4 (generate fresh)
name	string	Internal name for the plugin
marketData.name	string	Display name in plugin explorer and app dashboard
marketData.description	string	Description shown in plugin explorer and app dashboard
marketData.logoUrl	string	Path to logo file ({{BASE_URL}} resolves to public folder)
placements	array	Array of slot placements where plugin can be added
placements.appDefinitionId	string	ID of the Wix app containing the slot
placements.widgetId	string	ID of the page containing the slot
placements.slotId	string	ID of the specific slot
installation.autoAdd	boolean	Whether to auto-add plugin to slots on app installation
tagName	string	HTML custom element tag (kebab-case, must contain a hyphen)
element	string	Relative path to plugin component
settings	string	Relative path to settings panel component

Step 2: Register in Main Extensions File

CRITICAL: After creating the plugin-specific extension file, you MUST read wix-cli-extension-registration and follow the "App Registration" section to update src/extensions.ts.

Without completing Step 2, the site plugin will not be available in the plugin explorer.

Examples

For complete examples with all three required files (plugin component, settings panel, extension configuration), see EXAMPLES.md.

Example use cases:

• Best Seller Badge - Customizable badge on product pages with text and color settings
• Booking Confirmation - Custom confirmation message for booking pages
• Product Reviews Summary - Star rating and review count display
• Data-Driven Plugin - Plugin with Wix Data API integration and editor environment handling

Best Practices

Implementation Guidelines

• Use inline styles - CSS imports are not supported in custom elements
• Handle editor environment - Show placeholders when in editor mode for data-dependent plugins
• Editor sandboxing - Plugins are sandboxed in the Editor; localStorage, sessionStorage, and cookies are restricted. Use viewMode() to detect editor and mock storage if needed
• Validate all input - Check required props are present
• Follow naming conventions - kebab-case for all attributes and widget API
• Keep plugins focused - Each plugin should do one thing well
• Test in multiple slots - If supporting multiple placements, test each one

Performance Considerations

• Keep bundle size small - plugins load on user-facing pages
• Avoid heavy computations on initial render
• Lazy load data when possible
• Use efficient re-rendering patterns

Verification

After implementation, use wix-cli-app-validation to validate TypeScript compilation, build, preview, and runtime behavior.

Code Quality Requirements

• Strict TypeScript (no any, explicit return types)
• Native HTMLElement class for plugin components
• React functional components with hooks for settings panels
• Proper error handling and loading states
• No @ts-ignore comments
• Inline styles via template strings (no CSS imports)
• Handle Wix Editor environment when using Wix Data API
• Consistent attribute naming using kebab-case throughout