Interest Groups and Same Origin

Joining IG With Same Domain but Different Origin

Conclusion: does not work without a delegation file

Here we try to join an IG owned by the same site as the frame, but in a different origin. The sites delegation file will return true for the www, auctions, and interest-groups subdomains, but not creatives subdomain.

            
Client Side Code 
            
        function joinUsingOrigin(origin) {
            const myGroup = {
              'owner': origin,
              'name': 'womens-running-shoes',
              'biddingLogicUrl': origin + 'biddingfunction.js',
              'ads': [{renderUrl: origin + 'creative?id=23'}],
              'trustedBiddingSignalsURL': origin + 'buyer-kv-call',
              'lifetimeMs': 3600
            };
            const joinPromise = navigator.joinAdInterestGroup(myGroup);
        }
        window.onload = async function() {
            window.joinUsingOrigin("https://creatives.privacy-sandbox-testing-one.com/");
        }
            
            
Well Known Delegation Logic
            
              fastify.get("/.well-known/interest-group/permissions/", function(request, reply) {
                const queryParamValue = request.query.origin;
                const submittedOrigin = decodeURIComponent(queryParamValue);
                submittedOrigin.trim();
                const validOrigins = [
                  'https://www.privacy-sandbox-testing-one.com',
                  'https://auctions.privacy-sandbox-testing-one.com',
                  'https://interest-groups.privacy-sandbox-testing-one.com',
                ]; // note creatives is intentionally not in here, want it for experiment
                var val = 'false';
                if (validOrigins.includes(submittedOrigin)) {
                  val = 'true';
                }
                return '{ "joinAdInterestGroup": ' + val + ', "leaveAdInterestGroup": ' + val + '}';
              });