# Server-Side Tracking

> Capturing a conversion server-to-server — recorded on an external system's server and sent into AnyTrack's server via a Postback URL, incoming webhook, or REST API — with no browser involved.

Server-side tracking (also **server-to-server** or **S2S**) is how a conversion reaches AnyTrack without a browser. The conversion fires in an external system, is recorded on that system's server, and is then sent server-to-server into AnyTrack's server — through a [Postback URL](/glossary/postback-url), an [incoming webhook](/glossary/incoming-webhook), or a REST API call. A classic example: an affiliate network's tracking server notifies AnyTrack of a credited sale.

**The inbound side of going server-side.** The outbound side — delivering conversions to ad platforms — is [Server-Side Tagging](/glossary/server-side-tagging). The full chain is server-side tracking in, server-side tagging out.

## What Server-Side Tracking means for each marketer

- **Affiliate marketer:** The core inbound path — the network's server calls a [Postback URL](/glossary/postback-url) with the Click ID when a sale is credited.
- **eCommerce marketer:** Store and checkout events (Shopify order webhooks) confirm the Purchase server-side even when the browser pixel is blocked.
- **Lead-gen marketer:** CRM and offline-close events (HubSpot, Stripe) flow in via incoming webhooks, often reshaped through Zapier or Make first.
- **Business owner:** The "data coming in" side — their own app or funnel server tells AnyTrack a conversion happened.

## Server-Side Tracking vs Server-Side Tagging vs Conversion API

- [Server-Side Tagging](/glossary/server-side-tagging) — the outbound counterpart: tracking captures conversions *into* AnyTrack; tagging delivers them *out* to ad platforms.
- [Conversion API](/glossary/conversion-api) — the outbound channel to ad platforms; server-side tracking is the inbound capture. Don't equate "server-side" with "CAPI".

## How AnyTrack uses Server-Side Tracking

Once a conversion is captured server-side, AnyTrack stores and attributes it in the Data Store, then forwards it to your ad platforms via [Server-Side Tagging](/glossary/server-side-tagging). Incoming webhooks that bring store and app conversions in are included on **all** plans (Free included), because they are an inbound channel. Affiliate [Postback URLs](/glossary/postback-url) require a **paid** plan and the [Tracking Tag](/glossary/tracking-tag) installed so AnyTrack can match the Click ID — and a postback must never be trimmed, since removing the Click ID parameter breaks the match.