Tracking and measurement
Conversions API (CAPI)
Meta's interface for sending conversion events directly from a server. Often used alongside the pixel with deduplication.
The Conversions API is Meta's interface for sending events such as purchases directly from a server to Meta, instead of or alongside the browser pixel. It carries the event, its value and the customer information used for matching, hashed before it is sent. It is the Meta side of server-side tracking.
Most stores run CAPI and the pixel together. The pixel fires in the browser, the server sends the same event through CAPI, and a shared event ID lets Meta discard the duplicate. The server event is the reliable one: it arrives even when the pixel is blocked, and it can carry the corrected value after costs or refunds.
CAPI quality shows up as event match quality in Meta's interface and, less visibly, in how well value optimisation works. An assistant connected to Meta's ads AI connectors reads the results of that tracking but cannot fix it; when campaign figures look wrong, the CAPI setup and the deduplication are the first things to check.