Skip to content
The Madison Avenue Field GuideA field guide to marketing & advertising, by Brandon Mina

GlossaryMeasurement & AttributionConversion API (CAPI)

Measurement & Attribution

Conversion API (CAPI)

A server-to-server connection that sends conversion events directly to ad platforms.

By Brandon MinaCEO, BrandPilot AIUpdated November 2026

Short answer

A Conversion API (CAPI) is a server-to-server connection that sends conversion events, such as purchases and leads, directly from a business's systems to an ad platform like Meta. Because it bypasses the browser, it is less affected by ad blockers, cookie limits and tracking restrictions, improving measurement accuracy and campaign optimization alongside pixels.