# Attribution — Understand what actually worked — Runner

> Runner keeps your first-party events, reconciles them against your GA4 property day by day, and can hold back a share of any audience you build so there is something to compare against. Usually bought as HockeyStack or GA4.

Canonical: https://www.runtheworld.ai/product/attribution

**Built into Runner**

- Plans and creates your GA4 property in your own Google account, then reads the setup back to check it
- Reconciles it against your own first-party events
- Holdout groups on the audiences you build

**Worth knowing** Every number here is worked out from data you already hold — your own events, rather than a tracking script watching the rest of your tools.

Usually bought as HockeyStack or GA4.