Multisite Override Style

Network-wide CSS and theme.json overrides for WordPress Multisite. Enforce brand consistency across all subsites from a single admin panel.

Features

• CSS Override — CodeMirror editor, appended after all theme stylesheets (priority 9999)
• theme.json Override — Visual fields (colors, typography, spacing, borders) + raw JSON editor
• Deep Merge — Values merged into the Global Styles (user) layer via wp_theme_json_data_user
• Per-Site Exemptions — Network admin can exempt individual sites
• Revision History — Last 10 saves with one-click restore
• Preview — Test changes on a live site before saving
• Import / Export — JSON bundle for dev → staging → production promotion
• Block Theme Aware — theme.json applies to block themes only; classic themes get CSS only

Requirements

• WordPress Multisite 6.8+
• PHP 8.3+
• Network activation only

Installation

From GitHub Release (recommended)

1. Download the latest multisite-override-style.zip from Releases
2. Upload via Network Admin → Plugins → Add New → Upload Plugin
3. Network Activate from Network Admin → Plugins

The plugin includes automatic updates — you’ll see new versions in WordPress like any other plugin.

For Development

cd wp-content/plugins
git clone https://github.com/soderlind/multisite-override-style.git
cd multisite-override-style
composer install
npm install && npm run build

Then Network Activate from Network Admin → Plugins.

Usage

Navigate to Network Admin → Themes → Override Style.

Tab	Purpose
CSS	Raw CSS editor (CodeMirror)
theme.json	Visual fields + Raw JSON
Sites	Per-site exemption toggles
History	Revision list with restore
Import / Export	JSON download/upload

Development

# Start dev server (hot reload)
npm run start

# Production build
npm run build

# Run PHP tests
composer test

# Lint JS
npm run lint:js

Project Structure

├── multisite-override-style.php   # Plugin bootstrap
├── src/
│   ├── Plugin.php                 # Hook wiring
│   ├── Admin/                     # Network admin page, REST API, Edit Site screen
│   ├── Override/                  # CSS + theme.json injection
│   ├── Preview/                   # Transient-backed draft preview
│   └── Storage/                   # Settings + Revisions repositories
├── resources/js/
│   ├── index.jsx                  # React entry
│   ├── api.js                     # REST client
│   └── components/                # React UI
├── build/                         # Compiled assets
├── languages/                     # POT file
└── tests/                         # PHPUnit + Brain Monkey

Hooks

Hook	Type	Description
wp_theme_json_data_user	Filter	Merges network theme.json override
wp_enqueue_scripts (9999)	Action	Enqueues network CSS override

REST API

All endpoints require manage_network capability.

Method	Endpoint	Description
GET	/wp-json/mos/v1/settings	Current CSS, theme.json, exemptions
POST	/wp-json/mos/v1/settings	Save settings (creates revision)
GET	/wp-json/mos/v1/revisions	List last 10 revisions
POST	/wp-json/mos/v1/revisions/{id}/restore	Restore a revision
GET	/wp-json/mos/v1/sites	All sites with exemption status
POST	/wp-json/mos/v1/sites/{id}/exemption	Toggle exemption
POST	/wp-json/mos/v1/preview	Create draft, returns preview URL
DELETE	/wp-json/mos/v1/preview/{token}	Discard draft
GET	/wp-json/mos/v1/export	Download settings bundle
POST	/wp-json/mos/v1/import	Import settings bundle

License

GPL-2.0-or-later

Author

Per Søderlind

📦 Source: soderlind/multisite-override-style · Edit on GitHub