GA4 e-commerce end to end through your server container

GA4 fills its e-commerce reports only from events with the recommended names. Custom names such as productView or checkout_step_2 are stored, but they never show up as product views or revenue. Use these names exactly, in lowercase:

• view_item_list and select_item: a visitor sees a product list (category page, search results) and clicks a product in it.
• view_item: a product detail page.
• add_to_cart, remove_from_cart and view_cart: cart actions.
• begin_checkout, add_shipping_info and add_payment_info: the checkout steps.
• purchase: the completed order.
• refund: a full or partial refund, usually sent from your backend rather than the browser.

Every event carries an items array, and each item needs at least item_id or item_name. When an event has a value, it also needs currency (for example EUR), otherwise GA4 cannot turn it into revenue. purchase and refund also need a transaction_id.

Each push has two parts: first ecommerce: null, then the event with a fresh ecommerce object. The dataLayer merges objects, so without the reset the items from the previous event can leak into the next one, for example a product from view_item ending up in add_to_cart.

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({ ecommerce: null });
window.dataLayer.push({
  event: 'view_item',
  ecommerce: {
    currency: 'EUR',
    value: 129.90,
    items: [{ item_id: 'SKU-1', item_name: 'Shoes', item_brand: 'Acme', item_category: 'Footwear', price: 129.90, quantity: 1 }]
  }
});

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({ ecommerce: null });
window.dataLayer.push({
  event: 'add_to_cart',
  ecommerce: {
    currency: 'EUR',
    value: 129.90,
    items: [{ item_id: 'SKU-1', item_name: 'Shoes', price: 129.90, quantity: 1 }]
  }
});

The purchase push adds transaction_id and the full order value. Render it on the thank-you page with the real order data from your shop.

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({ ecommerce: null });
window.dataLayer.push({
  event: 'purchase',
  ecommerce: {
    transaction_id: 'T-10293',
    value: 129.90,
    currency: 'EUR',
    items: [{ item_id: 'SKU-1', item_name: 'Shoes', price: 129.90, quantity: 1 }]
  }
});

In the web container you do not need a tag per event. One Google Analytics: GA4 Event tag can read the event name and the e-commerce data from the dataLayer and send whichever event was pushed.

1. 1 Create a trigger of type Custom Event. As the event name enter ^(view_item_list|select_item|view_item|add_to_cart|remove_from_cart|view_cart|begin_checkout|add_shipping_info|add_payment_info|purchase)$ and tick Use regex matching.
2. 2 Create a tag of type Google Analytics: GA4 Event. Enter your measurement ID G-XXXXXXXXXX (or select your Google tag) and set Event Name to the built-in variable {{Event}}.
3. 3 Under More Settings open Ecommerce, tick Send Ecommerce data and choose Data Layer as the data source.
4. 4 Attach the Custom Event trigger, name the tag (for example GA4 - ecommerce) and save.

The tag goes out through the same Google tag that already has server_container_url set to https://sgtm.example.com from lesson 3, so every e-commerce event reaches your server container first.

Nothing. The GA4 client claims the e-commerce hits like any other GA4 event, and the items travel inside the hit. The GA4 tag from lesson 4, triggered on Client Name equals GA4, forwards them to Google Analytics together with value, currency and transaction_id.

The server container is still the right place for extra destinations. A Meta Conversions API tag can read the same purchase event, so the order is sent to Meta from the same data (lesson 7 shows how to share an event_id for deduplication). The Google Ads conversion tag in the next lesson reads it too.

Google Analytics deduplicates purchase events with the same transaction_id for data from web streams. Treat that as a safety net, not as the fix. The common source of duplicates is the thank-you page: a visitor refreshes it, comes back through the browser history or opens the confirmation link from the email, and the purchase push runs again.

• Render the purchase push only on the first view of the thank-you page. Keep a flag on the order in your shop (for example tracked_at) and skip the push when it is set.
• Always send a real, unique transaction_id. Never an empty string: GA4 treats all purchases with transaction_id set to an empty string as one transaction.
• Do not put personal data such as the email address in transaction_id. Use the order number.
• Send refunds with the transaction_id of the original order, so GA4 can match them.

Test in three places, from the server outwards. Open Preview in both containers and go through the shop: view a product, add it to the cart, check out and place a test order.

• Web preview: the GA4 - ecommerce tag fires on each e-commerce event and not on others.
• Server preview: the request goes to sgtm.example.com, and in the event data you see items with item_id, price and quantity, plus value and currency.
• Server preview: the GA4 tag is listed under Tags Fired for purchase.
• GA4 DebugView: the events arrive with their parameters and items.
• GA4 Monetization reports: purchases and revenue appear. These reports can take 24 to 48 hours to fill, so do not judge them on the same day.