v132 · miscellaneous

Attribution Reporting API Feature (Change To ar_debug Cookie Requirement)

We are landing the following change to the Attribution Reporting API focused on: * making it easier to receive API cookie-based debug reports

concepts

  1. ar_debug cookie change

    Attribution Reporting relaxes the ar_debug cookie requirement when partitioning provides equivalent privacy. Less ceremony to enable debug output.

  2. debug-keys matrix

    Walk the source-debug / trigger-debug / verbose-debug eligibility table; see which ones light up when partitioning is on but the ar_debug cookie isn't.

  3. verbose debug decoder

    Pick a failure mode — source-storage-limit, trigger-no-matching-source, named-budget-insufficient — and inspect the JSON payload Chrome would POST to /.well-known/attribution-reporting/debug/verbose.

  4. ad-tech migration checklist

    Interactive cleanup checklist for teams already running an ar_debug pipeline. Tick off cookie-banner, policy, dashboard and e2e fixture changes; export as markdown.

why it shipped

Currently the API allows cookie-based debug reporting only if third-party cookies are available AND the API caller sets the special unpartitioned ar_debug cookie.

references