Some of our clients want to migrate to server-to-server (S2S) integration for various reasons (unwillingness of having third-party scripts running, etc). Even this goes a bit against the philosophy of the PSB, we think that some middle ground may be found to accommodate this use case.

In S2S integration, advertiser send with some delay the event to the adtech directly without mediation from the user agent. This means that the adtech cannot register triggers when the user interacts with the advertiser’s website.

To allow for the late registration of events in ARA, we propose the following mechanism:

When the user interacts with the advertiser’s website, instead of registering a trigger, the adtech would register a promise from ARA for a late registration, which would declare an URL for late trigger registration and a waiting period (which could be capped to sensible values).

At a random time after the end of the waiting period, the user agent would call the adtech on the URL for late trigger registration. This call would allow the adtech to register one or several triggers. To allow for a correct ordering and priority of triggers, this new trigger registration mechanism would enable declaring the actual time of the event in the past. Note that we don’t want to challenge the source expiry system, ie late triggers would not be eligible for attribution to sources which expire between the actual timestamp of the event and the timestamp of its “late-registration”.

Do you think that such a system could be implemented?