Comment by amadeuspagel
3 years ago
The original discussion was comparing the Topics API to third party cookies.
The way that the Topics API works is that a website that could have set a third party cookie will instead be able to observe a topic, and will then be able to get that topic in the future.
The comment I responded to claimed that Topics API doesn't use the full history and that a site X won't get topics derived for site Y: https://news.ycombinator.com/item?id=37429447
> Topics API doesn't use the full history
That's true, or rather no site gets access to the full history, or to topics that are derrived from the full history, but only to that part of the history that it "observed".
> a site X won't get topics derived for site Y
Unless site Y allowed them to, which of course site Y can also do by allowing them to set a third party cookie.