🔴 Phase 1 — Core · Drives dynamic retargeting and catalog matching.

view_item

When to push

When the product detail page (PDP) renders.

Push once per view. If the user switches variants without changing page, don't re-push (unless it's a distinct SKU in the catalog).

Example

window.dataLayer.push({ ecommerce: null });
window.dataLayer.push({
  event: 'view_item',
  ecommerce: {
    currency: 'EUR',
    value: 42.00,
    items: [
      {
        item_id: 'BIO-CRM-001',
        item_name: 'Hydrating Day Cream',
        item_brand: 'Biosphere',
        item_category: 'Skincare',
        item_category2: 'Face',
        item_category3: 'Hydration',
        item_variant: '50 ml',
        price: 42.00,
        quantity: 1
      }
    ]
  },
  user_data: /* if user logged in, see Foundations */
});

Parameters

Event level

Parameter	Type	Required
currency	string	required
value	number	required — displayed product price
items	array (1 item)	required

Item level

• item_id required
• item_name recommended
• price, quantity (= 1) recommended
• item_brand, item_category*, item_variant recommended

Platforms

Platform	Native event	Notes
GA4	view_item
Meta	ViewContent	content_ids = [item_id], content_type = 'product'
Google Ads	Dynamic remarketing	Matches GMC id

Critical for the Meta Catalog

The item_id you send must match exactly an id in the Meta Catalog feed, otherwise dynamic retargeting (DPA) won't match.

Pitfalls

• ❌ Pushing view_item on every variant swap (image carousel, color picker) → event spam.
• ❌ Missing currency or value → Meta ViewContent loses value information.
• ❌ item_id ≠ Meta Catalog id → DPA audiences broken.