Existing tags compatibility

Eureka reads the calls your site already makes to other analytics tools, so you don't have to retag. It never replaces them:

• the tool's original function is always called, with the same arguments, and its result is passed through;
• Eureka's own handler runs in a try/catch, so it can never break your tags;
• tools that load after Eureka, or replace their globals, are re-hooked automatically (polling for 30 s, plus page load events);
• a click or page view reported by a tool enriches the event Eureka captured itself instead of creating a duplicate. Tool page views are not counted again by default (bridges.pageviews: false); their naming (Piano page and chapters, Adobe pageName…) is attached to Eureka's page events.

Every event keeps its source (src) and its original name (on), so you can trace it back to your tracking plan.

Tool	What is read	Highlights
Google tag (gtag.js) / GA4	dataLayer gtag entries	GA4 event names are Eureka's canonical model. view_search_results → search, file_download → download, user_id → hashed user ID, consent commands
Google Tag Manager	dataLayer.push({event})	GA4 ecommerce.items, Universal Analytics enhanced ecommerce (add, remove, checkout, purchase, detail, click, impressions, promoClick…), custom events with their properties. gtm.* system events ignored.
Matomo / Piwik	_paq.push	trackEvent → event named after the action, trackGoal, trackSiteSearch, trackLink, cart and trackEcommerceOrder → purchase, setUserId, consent calls
Piano Analytics	pa.sendEvent(s), pa.privacy.setMode	page.display, click.*, product.*, cart.*, transaction.confirmation → purchase, internal_search_result.display → search, publisher and self-promotion events, av.*
AT Internet SmartTag	ATInternet.Tracker.Tag instances	page.send, page.set + dispatch(), click.send (action, navigation, download, exit); names chapter1::chapter2::name
Adobe Analytics	s.t(), s.tl()	pageName, events prodView, scAdd, scRemove, scView, scCheckout, purchase, products string
Segment / RudderStack	analytics.track/page/identify	Segment ecommerce spec (Order Completed → purchase…)
Meta pixel	fbq	ViewContent, AddToCart, InitiateCheckout, AddPaymentInfo, Purchase, Lead, CompleteRegistration, Search, custom events

Turn a bridge off:

eureka('config', { bridges: { fbq: false } })

To rename events or map a custom name to a canonical one (for example a Matomo event Cart/Add to add_to_cart), use Admin → Event mappings.