As cookies continue to degrade and tracking accuracy drops, Pinterest’s Conversion API (CAPI) is now crucial for eCommerce advertisers. By combining server-side tracking with product catalog events, you can significantly improve Pinterest’s ability to match users, attribute sales, and optimize campaigns for ROAS.

🧰 Prerequisites

Requirement	Notes
OpenCart (v3.x or v4.x)	With template access
Pinterest Tag ID	From Pinterest Ads Manager
Pinterest CAPI Access Token	From Ads Manager (CAPI setup)
GTM Web + Server Containers	Installed and deployed
Product Feed Catalog	Synced via Pinterest Business Manager

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🎯 What You’ll Track

Event	Purpose
PageVisit	Product pageview
AddToCart	Intent event
Checkout (Purchase)	Conversion + value
Product ID	Synced with Catalog Feed (via model in OpenCart)

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🗂️ Implementation Plan

OpenCart Pages → Web GTM Pushes Event → Server GTM Receives + Sends to Pinterest CAPI

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🔹 Step 1: Generate Pinterest Access Token

1. Go to Pinterest Ads Manager → Conversions → API Access
2. Create a new CAPI token
3. Save:
   • Pinterest Tag ID (e.g., 2612238051234)
   • Access Token

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🔹 Step 2: Setup DataLayer Push on Product Page

Edit: catalog/view/theme/*/template/product/product.twig

<script>
window.dataLayer = window.dataLayer || [];
dataLayer.push({
  event: 'pinterest_view_item',
  product_id: '{{ product.model }}',
  product_name: '{{ product.name|escape('js') }}',
  value: '{{ product.price }}',
  currency: '{{ session.currency }}',
  event_id: 'pin_{{ product.product_id }}_{{ microtime(true) | round(0, 'common') }}'
});
</script>

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🔹 Step 3: Track AddToCart on AJAX Cart Add (Optional Enhancement)

Update the controller handling add to cart (usually catalog/controller/checkout/cart.php) to also respond with a DataLayer-friendly payload (or track via MutationObserver if it’s client-side JS).

For simplicity, let’s inject on product pages using a click listener in Web GTM.

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🔹 Step 4: Track Purchase on Success Page

In catalog/controller/checkout/success.php:

$order_id = $this->session->data['order_id'];
$order_info = $this->model_checkout_order->getOrder($order_id);
$products = $this->model_checkout_order->getOrderProducts($order_id);

$items = [];
foreach ($products as $p) {
  $items[] = $p['model'];
}

$email = strtolower(trim($order_info['email']));
$phone = preg_replace('/\D/', '', $order_info['telephone']);

$data['pinterest_purchase'] = json_encode([
  'event' => 'pinterest_purchase',
  'product_ids' => $items,
  'value' => $order_info['total'],
  'currency' => $order_info['currency_code'],
  'email' => hash('sha256', $email),
  'phone' => hash('sha256', $phone),
  'event_id' => uniqid('pin_purchase_', true)
]);

In success.twig:

<script>
window.dataLayer = window.dataLayer || [];
dataLayer.push({{ pinterest_purchase|raw }});
</script>

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🔹 Step 5: Web GTM – Set Up Triggers

Trigger 1: pinterest_view_item
Trigger 2: pinterest_add_to_cart
Trigger 3: pinterest_purchase

✅ Each trigger sends an event to the Server GTM endpoint (e.g., via fetch or GA4 transport)

Optional JS Fetch Forwarding:

fetch('https://gtm.yoursite.com/event', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    event_name: '{{DL - event}}',
    product_ids: {{DL - product_ids}},
    value: '{{DL - value}}',
    currency: '{{DL - currency}}',
    email: '{{DL - email}}',
    phone: '{{DL - phone}}',
    event_id: '{{DL - event_id}}',
    action_source: 'website'
  })
});

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🔹 Step 6: Setup Pinterest CAPI in Server-Side GTM

1. Import or create a Pinterest Conversion API Tag (use custom HTTP request tag or template)
2. Request URL:
   https://api.pinterest.com/v5/events
3. Payload Example:

{
  "event_name": "checkout",
  "event_time": {{Timestamp}},
  "event_id": "{{event_id}}",
  "action_source": "website",
  "user_data": {
    "em": "{{email}}",
    "ph": "{{phone}}"
  },
  "custom_data": {
    "currency": "{{currency}}",
    "value": {{value}},
    "content_ids": {{product_ids}},
    "content_type": "product"
  }
}

4. Header Setup:

Header	Value
Authorization	Bearer YOUR_ACCESS_TOKEN
Content-Type	application/json

5. Trigger: Custom Trigger for each event name:
   • Event equals pinterest_purchase
   • Event equals pinterest_view_item
   • Event equals pinterest_add_to_cart

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🔹 Step 7: Ensure Deduplication

• Send unique event_id in both pixel and CAPI (if you also implement client pixel)
• Pinterest automatically deduplicates based on event_id

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🧪 QA & Debugging

Tool	Use
Server GTM Preview	Verify event data and API response
Pinterest Event Manager	Confirm CAPI events
Chrome → DevTools → Network	Validate fetch or pixel delivery
Pinterest Tag Helper Extension	Debug client-side tags

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🔐 Bonus: Set Cookie for epik (Pinterest Click ID)

In header.twig:

<script>
const epik = new URLSearchParams(window.location.search).get('epik');
if (epik) {
  document.cookie = `epik=${epik}; path=/; max-age=2592000; SameSite=Lax`;
}
</script>

✅ You can later read this cookie in Server GTM via event.data.cookie.epik.

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📦 Architecture Overview

[OpenCart Product or Success Page]
    ↓
[dataLayer Push (Web GTM)]
    ↓                         ↘
[Pixel (optional)]       [Fetch → Server GTM]
                                ↓
                         [Pinterest CAPI]

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