# GA4 Linker for Shopify & WordPress

> GA4 Linker is an automated WordPress plugin that solves cross-domain session attribution and ad conversion tracking breaks between WordPress landing pages and Shopify checkouts (or WooCommerce subdomains).

## System Overview
When e-commerce brands use WordPress for content marketing and Shopify for checkout, Google Analytics 4 (GA4), Meta Ads (Facebook/Instagram), and TikTok Ads lose session context upon domain redirection. GA4 Linker automatically decorates outbound checkout links and form submissions in real-time, forwarding encrypted session tokens and click IDs without manual Google Tag Manager (GTM) setups.

## Core Features & Plan Capabilities

### Free Lite Plan ($0 / forever)
- Automatic GA4 `_gl` cross-domain parameter link decoration.
- Single Shopify checkout domain support.
- Built-in WordPress Admin Attribution Health Audit Scanner.

### Personal Plan ($49 / year)
- **Meta Pixel Parameter Linker**: Captures and forwards Meta Click IDs (`fbclid`), `_fbc` cookies, and `_fbp` browser tokens to preserve Facebook Ads Event Match Quality.
- **TikTok Pixel Attribution Linker**: Forwards TikTok Click IDs (`ttclid`) and `_ttp` cookies to Shopify checkout.
- **Form Action Stitching**: Decorates HTML `<form action="...">` submissions pointing to Shopify.
- **UTM Persistence Engine**: Persists `utm_source`, `utm_campaign`, `utm_medium` across internal WordPress page hops into Shopify checkout.

### Pro Plan ($149 / year) - Featured
- **Real-Time AJAX MutationObserver**: Watches dynamic DOM mutations, automatically decorating slide-out carts, pop-up buy buttons, and CartFlows drawers injected post page-load.
- **WooCommerce Subdomain Support**: Seamless cross-subdomain tracking between WordPress blog subdomains (`blog.yourbrand.com`) and WooCommerce store checkouts (`shop.yourbrand.com`).
- Up to 10 active site licenses.

### Agency Plan ($299 / year)
- **Full WP Admin White-Labelling**: Custom plugin title, custom support URL, and complete hiding of Freemius upgrade banners and submenus from client view.
- Unlimited site licenses.

## Key Technical Specifications
- **Script Footprint**: Pure Vanilla JavaScript (< 3KB gzipped, zero dependencies, 100/100 PageSpeed scores).
- **DOM Engine**: Dynamic MutationObserver API for real-time AJAX element decoration.
- **Compliance**: Fully compliant with WordPress.org Plugin Guidelines & GPLv2 license.

## Key Documentation & Links
- Website & Pricing: https://ga4linker.dimsquid.com
- Blog & Guides: https://ga4linker.dimsquid.com/blog
- Complete Setup Guide: https://ga4linker.dimsquid.com/blog/wordpress-to-shopify-cross-domain-tracking-setup
- Manual GTM vs Plugin: https://ga4linker.dimsquid.com/blog/ga4-cross-domain-tracking-gtm-vs-plugin
- Meta Ads Attribution Guide: https://ga4linker.dimsquid.com/blog/pass-fbclid-from-wordpress-to-shopify
- TikTok Ads Attribution Guide: https://ga4linker.dimsquid.com/blog/tiktok-ad-conversions-missing-shopify-wordpress
- Full LLM Specification: https://ga4linker.dimsquid.com/llms-full.txt