CAPI (Conversions API)

CAPI is a server-side way to send conversions to Facebook directly from a server or tracker, bypassing the browser entirely. It's more reliable than a standard pixel because it doesn't depend on ad blockers, Safari's ITP, or other client-side restrictions.

How CAPI differs from a standard pixel

A pixel sends events from the user's browser, so it can be blocked; CAPI sends the same events from a server, where there's nothing to block. In practice the two are used together — the platform matches and deduplicates signals from the pixel and from CAPI to build a more complete picture of conversions.

CAPI in PWA arbitrage

CAPI matters especially for PWAs because a share of traffic comes from mobile browsers with strict privacy settings, where a browser pixel loses a noticeable chunk of events. A Keitaro-to-FB-CAPI integration is built into APEX out of the box, so a buyer doesn't need to wire up server-side delivery manually, which usually takes separate technical work.

FAQ

Why use CAPI if a pixel is already set up?
A pixel loses some events to browser-side blocking, and CAPI recovers them by sending the same events from the server instead. Together they give the platform fuller, more accurate data to optimize on.
How do you set up CAPI for PWA offers?
CAPI is usually configured through a tracker that receives conversions from the PWA and forwards them to the ad platform over a server channel. In APEX, that Keitaro-to-FB-CAPI link is already built in, with no separate development needed.
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