Glossary · Mesurer proprement

Server-side conversion API

A server-side conversion API is a way of declaring a conversion directly from one server to another, without going through the visitor's browser. The amount and the customer's identity therefore never cross a machine you do not control.

Cookies, consentement, serveur : mesurer la campagne sans pister la personne. The forty terms of the trade

What it is for

It settles two problems at once. Reliability: a blocker, a closed tab or a dropped connection no longer make a sale disappear. And integrity: an amount sent by a browser can be rewritten by anyone, which makes any money figure disputable.

How it is wired

A secret key on the server side, a call at payment time, and the click identifier sent along with the amount. The key must never end up in a page: everything sent to the browser is public, however carefully it is handled.

The classic mistake

Declaring the sale from the thank-you page. It is not always reached, it can be reloaded ten times, and its content can be edited by the visitor — three different ways to distort revenue.

Webhook

Where a sale is declared from

The visitor's browser

Your server

The first path is convenient and forgeable. The second asks for a key, and holds up in front of a client.

The API, and how to call it

What Subtraq does with it

It is a product rule: sales only arrive through the server, with a key. An amount posted from a browser is worth nothing. A single tool registry serves the API, the MCP server and the documentation — adding a tool is one entry, not three implementations.