Google Analytics 4

1Role / Purpose

GA4 plays a dual role in our stack:

2Server-Side Architecture

Full flow

Addingwell DataLayer
      |
GTM Web Container
      |
GA4 Config Tag (transport_url = sGTM)
      |
Server-Side GTM (custom domain)
      |
+-- GA4 Server Tag --> Google Analytics
+-- Meta CAPI Tag --> Meta Conversions API
+-- Google Ads Tag --> Enhanced Conversions
+-- Other server-side destinations

Why server-side?

• Bypasses adblockers (first-party custom domain)
• More reliable data (no client-side loss)
• Consent Mode handled server-side
• A single collection point for every destination
• ITP cookie restore via Addingwell

3Data Transport

In our architecture GA4 acts as the transport layer between the GTM Web container and the sGTM. GA4 events carry everything the destinations need.

server_container_url

The server_container_url field in the GA4 Config tag redirects hits to the sGTM instead of google-analytics.com.

Without server_container_url:
browser --> google-analytics.com (blocked by adblockers)

With server_container_url:
browser --> tags.my-store.com --> sGTM --> GA4 + destinations

GA4 data flow

GA4 is wired automatically through the server-side transport. The GA4 Config tag in the GTM Web container sends hits to the sGTM custom domain (first-party). The sGTM receives and distributes them.

GTM Web (client)
--> GA4 Config + Transport tag
  --> HTTP request to the sGTM custom domain (first-party)

sGTM (server)
--> GA4 Client (receives the request)
  +-- GA4 Server tag --> Google Analytics 4
  +-- META - CAPI - All Events --> Meta (Full CAPI, server-only)
  +-- GADS - Conv - purchase --> Google Ads Enhanced Conversions
  +-- (coming soon) TikTok Events API, Snap CAPI

Server-side enrichment:
- Automatic SHA-256 hashing (email, phone, address)
- Attribution cookies (fbp, fbc, gclid, wbraid, gbraid)
- event_id for deduplication
- Consent Mode v2 signals forwarded

What GA4 receives

• Every e-commerce event from the DataLayer (page_view, view_item, add_to_cart, purchase, and so on)
• Enriched parameters (items[], value, currency, transaction_id)
• Consent Mode v2 signals (analytics_storage, ad_storage)
• First-party attribution cookies (fbp, fbc, gclid) via cookie restore

What GA4 does not receive directly

• Plain-text PII (hashed server-side only)
• Events for other destinations (Meta, Google Ads): the sGTM handles those in parallel
• Events without analytics consent (only anonymised Advanced Consent Mode pings)

4E-commerce Events

Events tracked in GA4

Config Tag (GTM Web)

The GA4 Config tag in the GTM Web container sets up collection and transport to the sGTM.

GA4 Transport Tag

A second GA4 Event tag acts as transport for e-commerce events to the sGTM, forwarding DataLayer events to the server container.

GA4 Server Tag (sGTM)

The GA4 Server Tag in the sGTM receives events and forwards them to the Google Analytics property.

GA4 Client (sGTM) receives the hit
      |
GA4 Server Tag --> forwards to Google Analytics
      |
Other tags (Meta, Google Ads) --> read the same events
      |
Every destination receives the enriched data

• The GA4 Client parses incoming hits
• The GA4 Server Tag forwards to Google Analytics
• Other tags (Meta CAPI, Google Ads) fire on the same events
• No double sending: one GA4 hit feeds every destination

Conversions & attribution

In GA4, mark the key events as conversions:

Attribution model

• GA4 uses Data-Driven Attribution by default
• Modelled conversions compensate for data loss (consent, adblockers)
• Advanced Consent Mode sends anonymised pings even without analytics consent
• Google Ads conversions imported from GA4 benefit from the modelling

5Configuration

Prerequisites

• GA4 property created in Google Analytics
• Measurement ID (G-XXXXXXXXXX)
• Web stream configured
• sGTM custom domain configured (server_container_url)

Connectors

GA4 credentials are configured in Connectors:

DebugView & Realtime

DebugView

1. 1GA4 Admin → DebugView
2. 2Enable debug mode (GTM Preview or debug_mode=true)
3. 3Events appear in real time with all their parameters
4. 4Check the ecommerce parameters (items[], value, currency)
5. 5Check that events actually arrive (no gaps in the funnel)

Realtime

• GA4 Admin → Reports → Realtime
• Shows events from the last 30 minutes
• Useful for a quick check after a change
• Does not show detailed parameters (use DebugView for that)

6Verification

Verify the sGTM transport

1. 1Open the browser's Network tab
2. 2Filter by the custom domain (tags.my-store.com)
3. 3/collect requests must point to the sGTM
4. 4No direct request to google-analytics.com

Verify GA4 events

1. 1GA4 → DebugView (enable debug mode)
2. 2Browse the store: home → collection → product → cart → checkout
3. 3Check every event in the funnel
4. 4Check the ecommerce parameters (items[], value, currency)
5. 5Complete a test purchase → check purchase carries transaction_id

Verify consent

• Before consent: anonymised pings only (Advanced Consent Mode)
• After analytics consent: full events with GA4 cookies
• Check in GTM Preview Mode that consent really gates the tags

GA4-as-destination checks (Phase 3)

Checkpoints specific to GA4 as an sGTM destination:

• Events visible in GA4 Realtime after consent
• Requests sent through the sGTM custom domain (not googletagmanager.com)
• GA4 Server Tag active in the sGTM and forwarding to Google Analytics
• Check in GA4 → Admin → DebugView that events really arrive from the server

7Troubleshooting

8GA4 Checklist