Definition
The Conversions API (CAPI) is Meta’s server-to-server way to send website and offline events, such as Purchase or Lead, directly from your server to Meta.
In practice
Meta recommends running CAPI together with the browser pixel. Each source fills gaps in the other, and Meta deduplicates events that describe the same action.
CAPI events can include hashed customer parameters such as email and phone, plus the fbp and fbc cookies, which raise Event Match Quality and help optimization.
Similar server-side APIs exist for other platforms, including the LinkedIn Conversions API and the TikTok Events API.
Learn more: Meta Conversions API setup.
Related terms
- Event deduplicationEvent deduplication is how an ad platform recognizes that a browser event and a server event describe the same action, so the conversion is counted once.
- Event Match QualityEvent Match Quality (EMQ) is a score from 0 to 10 that Meta gives each event, showing how well its customer information can be matched to people on Meta.
- Server-side taggingServer-side tagging moves tag processing from the visitor’s browser to a server container you control.
How Markitech helps
Markitech connects your AI to Google Ads, GA4, Google Tag Manager, Meta and 12 more platforms, so it can check how Conversions API (CAPI) is set up in your own accounts and tags and propose fixes. Every change is held until you approve it.