Shopify setup

About 10 minutes. You'll need access to your theme code and the free Shopify Flow app.

1. Set your offer's landing URL

https://yourstore.myshopify.com/?s2s_click={click_id}

2. Save the click ID on the order

1
In Shopify admin go to Online Store → Themes → … → Edit code.
2
Open layout/theme.liquid and paste this just before </body>. Then save.

theme.liquid

<script>
  (function () {
    var KEY = 's2s_click';
    var id = new URLSearchParams(location.search).get(KEY);
    if (id) localStorage.setItem(KEY, id);
    id = id || localStorage.getItem(KEY);
    if (!id) return;
    // Attach the click ID to the cart so it is saved on the order
    fetch('/cart/update.js', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ attributes: { s2s_click: id } })
    });
  })();
</script>

This remembers the click ID when the visitor lands and attaches it to the cart, so every order carries an s2s_click attribute.

3. Send the postback with Shopify Flow

1
Install Shopify Flow from the Shopify App Store and create a new workflow.
2
Trigger: Order created, or Order paid if you only pay for paid orders.
3
Add a condition: the order's custom attributes include the key s2s_click.
4
Action: Send HTTP request, method GET, with this URL:

HTTP request URL

https://affn.io/api/public/postback?click_id={% for a in order.customAttributes %}{% if a.key == "s2s_click" %}{{ a.value }}{% endif %}{% endfor %}

Include &amount={{ order.currentSubtotalPriceSet.shopMoney.amount }}&order_id={{ order.name }} so percent and product commission rules apply. Turn the workflow on.

No Flow? Use a custom pixel (fallback)

Go to Settings → Customer events → Add custom pixel and paste the code below. It runs in the shopper's browser, so ad blockers can stop it. Use Flow whenever you can.

Custom pixel

const KEY = 's2s_click';
analytics.subscribe('checkout_completed', async () => {
  const id = await browser.localStorage.getItem(KEY);
  if (!id) return;
  fetch('https://affn.io/api/public/postback?click_id=' + encodeURIComponent(id), { keepalive: true });
});

Test your setup

Open a partner link and confirm the address bar shows ?s2s_click=…
Place a test order (Bogus Gateway or a 100% discount code)
In the order's Additional details, s2s_click is listed
Flow's run history shows the HTTP request with status 200
The conversion appears under Conversions in AFFN