demo · v131

Per-creative reach measurement

The motivating ad-tech use case for the 20→100 cap raise: a single auction needs to record reach + frequency + clicks-vs-impressions across many creatives in one call. With 20 you had to choose 6-7 creatives to track. With 100 you can track the full set of an advertiser's variants in a single contribution.

contributions needed
—
pre-131 (cap 20)
—
131+ (cap 100)
—

Green segments land, red spill. The increased cap doesn't change privacy guarantees — contribution budget per-epoch is unchanged — it just stops forcing ad-tech callers to drop signals they would otherwise have learned.

contribution layout

creativeimpressionsviewsclicks

the api

privateAggregation.contributeToHistogram([
  { bucket: 1n, value: 1 },   // creative A impression
  { bucket: 2n, value: 0 },   // creative A view (not visible)
  { bucket: 3n, value: 1 },   // creative A click
  // ... up to 100 contributions per call (was 20)
]);

see also