What is a Conversions API (CAPI)?

A Conversions API (CAPI) is the server-side channel an ad platform provides for reporting conversions directly from your backend, instead of relying on its browser pixel. Meta popularised the name with its Conversions API; Google has offline conversion import and enhanced conversions, and TikTok and Microsoft have their own equivalents.

Why it exists

Browser pixels lose conversions to ad blockers, cookie restrictions, and pages that fail to load. A Conversions API lets your server report the sale from a place none of that reaches, with the click id and hashed customer data attached for matching.

The catch

Each platform’s API is a separate integration with its own event format, and each needs careful deduplication against the existing pixel. Get it wrong and you either lose the data or count every sale twice. That is why most businesses use a tool rather than building it in-house.

Trakt runs every major Conversions API from one integration, deduplicated on event id, with a shadow mode that logs the exact payload before anything is sent so you can verify it first.