Server-side Awin affiliate tracking

Why server-side for Awin?

Affiliate networks like Awin rely on conversion tracking to calculate commissions. The client-side Awin Mastertag and conversion pixel lose 20–35% of conversions to ad-blockers, Safari ITP and consent banners — which means unpaid commissions to partners and under-reported sales. That's why Awin offers server-to-server (S2S) tracking: the conversion is sent straight from your server, not the browser.

How server-to-server tracking with Awin works

There are two phases. On the click-in from an Awin link the URL carries an awc parameter (the Awin click reference) — the unique click identifier that attributes the sale to the partner. DataNostro captures it and stores it in a first-party cookie, so it survives a multi-day path to purchase (unlike third-party cookies that Safari deletes).

On order completion the server-side GTM container fires a sale event straight to the Awin S2S endpoint — with the stored awc, advertiser ID, value, currency and order reference. No browser pixel, so there's nothing for an ad-blocker or ITP to block.

What gets sent to Awin over S2S

• awc — Awin click reference captured on click-in (the key to partner attribution)
• advertiserId — your Awin advertiser ID
• amount + currency — order value and currency
• ref / orderRef — order reference (also used for deduplication)
• commissionGroup — commission group if you split rates by category
• voucher — applied voucher code (optional, for voucher attribution)
• test mode — test flag to validate without a real commission

Server-to-server vs. the Awin Mastertag

The client-side Mastertag is good for journey tracking, but the conversion itself is fragile on it — one ad-blocker or a declined marketing consent and the sale goes uncounted. S2S is resilient: it runs on the server, out of reach of blocking. The best result is the combination — Mastertag for the journey, S2S for a reliable record of the sale.

Deduplication and accurate attribution

If you run both the Mastertag and S2S, Awin matches the two paths by ref (order reference), so the conversion isn't counted twice. DataNostro sends the same ref as the client tag — deduplication works out of the box and you see one clean conversion instead of two.

Setup in DataNostro — no developer

In Connections you enter your Awin advertiserId and API token, enable awc capture and map the sale event from your store. Done in minutes, no code changes. Works with the GA4 data layer and e-commerce platforms (Shopify, WooCommerce, PrestaShop).