What Is a Postback? Postback URL and S2S Explained

Postback (or postback URL) is an automatic notification one server sends to another when a specific event happens — for example, when a sportsbook, casino or broker confirms a sign-up or records a customer’s first deposit (FTD). So, what is a postback in one line? It’s how a conversion that happens on someone else’s system gets reported back to you.

How it works in practice

Instead of relying on a pixel running in the user’s browser, a postback works server to server (S2S): as soon as the event occurs in the source system (e.g. a payment platform, operator or broker), a request is fired to a URL configured beforehand, reporting the event and the tracking parameters tied to it (such as the click_id of the original click).

A generic postback URL template looks something like this (parameter names vary from platform to platform):

https://your-endpoint.example/postback?click_id={click_id}&event={event}&amount={amount}

The operator replaces the placeholders in braces with the real values at the moment of the event, so your side receives which click converted, which event it was (sign-up, FTD, redeposit) and how much was deposited.

This approach is more reliable than depending on the browser alone, because it isn’t affected by ad blockers, third-party cookies or lost sessions.

Where postbacks fit in Telegram tracking

In Track4you, the word shows up in two senses, running in opposite directions:

• Platform postback (Integrations): the sportsbook, casino or broker notifies Track4you. Each integration generates a tracking link (t4y.io/v2/...); on every click, Track4you creates a unique click_id and sends the lead to the platform’s sign-up page with that value in the URL. When the registration, FTD or deposit happens, the platform calls the integration’s postback URL (a server-to-server GET) returning the same click_id, and Track4you sends the conversion to Meta through CAPI. There’s no time limit on Track4you’s side: every conversion that arrives by postback, even weeks after the click, goes to the pixel and becomes a signal for the algorithm. Whether Ads Manager credits it to a campaign is decided by Meta’s attribution window (by default, 7 days after the click or 1 day after a view). Available on the Pro and Enterprise plans.
• Postbacks to your system: Track4you notifies your CRM, spreadsheet or automation (n8n, Make) of every funnel event — page view, button click, channel entry and exit — with a JSON POST. Up to 4, on any plan.

The platform postback is what lets a campaign optimize for people who deposit, not just people who enter the channel. Neither one attributes the channel entry itself: enter_channel is tied to the original click by the attribution window (up to 7 days after the click), with the tracking bot detecting the entry, without depending on a postback.

See the complete guide to tracking Telegram conversions and the iGaming S2S postback guide for the full flow, from click to deposit. For brokers, there’s also a binary options version.