ECAPI (Event and Conversion API)
The Event & Conversion API (commonly known as CAPI) is designed to standardize communication of marketing-related events from advertisers’ systems to advertising platforms and partners. The recipients are able to leverage this information to optimize marketing campaigns toward desired outcomes and to better measure and report on marketing campaign performance across complete marketing funnels. Available for Public Comment Until Friday, February 20, 2026
How an Event & Conversion API works
The Event & Conversion API defines a set of full-funnel events that are of interest to advertisers. By providing these events to partners, advertisers enable them to:
- Optimize ad campaigns toward desired outcomes
- Measure campaign performance throughout the marketing funnel
These capabilities enable advertising platforms and partners to improve campaign ROI through more effective targeting and better insight into what strategies lead to high value events.
This API is intended for server to server transmission from advertisers to their advertising partners/platforms to support measurement and optimization use cases. Advertisers will communicate events to partners through server-to-server calls to partner API endpoints. This specification standardizes the way these events are communicated.
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