AdAttributionKit
AdAttributionKit is Apple's successor to SKAdNetwork: a privacy-preserving framework that reports which ad campaign drove an install or re-engagement, without identifying the user.
It keeps SKAdNetwork's model — conversion values, postback windows, crowd-anonymity thresholds — and adds support for alternative app marketplaces and re-engagement on newer iOS versions. SKAdNetwork postbacks continue to arrive, so implementations generally handle both.
Like SKAdNetwork, it reports at campaign level, after a delay, and can't be enriched with user-level data by any provider.