Glossary
What is the Conversions API?
The Conversions API (CAPI) is Meta’s interface for sending conversion events to Meta directly from a server, instead of from the visitor’s browser through the Meta pixel. Server events can carry hashed customer identifiers, click IDs and order details, and are designed to run alongside the pixel with deduplication.
Technically, a Conversions API event is an HTTP request to Meta’s Graph API, addressed to your pixel (dataset) ID and authorized with an access token. Each event includes an event name, timestamp, action source and a user_data object with matching identifiers (hashed email and phone, fbc/fbp, IP address and user agent), plus custom_data such as order value and currency.
Because delivery is server-to-server, CAPI events are unaffected by ad blockers, Safari’s tracking prevention or a tab closed too early. The richer identifiers also tend to improve Event Match Quality, which in turn affects how many conversions Meta can attribute and optimize on.
CAPI complements the pixel rather than replacing it: both send the same event with a shared event_id, and Meta keeps one copy. Google and TikTok offer equivalent server-side interfaces (Google’s APIs and the TikTok Events API). Sending data server-side does not remove consent obligations: the same privacy rules apply.