>Based on my digging, invasions/coop appear to be in the works, with a pretty full client side implementation existing at release.
>You use an "avian key" item to "activate the power of Spacetime" opening your world for coop and invasions using the items shown in the video. The first item which produces the red effect triggers an event labeled "TransmitInvader" while the second item which produces the yellow effect triggers an event labeled "TransmitAssist"
>The third item appears to function similar to the red eye orb from Dark Souls/bloody finger from Elden Ring. Translation: "Searching for a world to invade" followed by "Matchmaking failed." There are game servers and API endpoints related to PVP/coop but as expected they are not accepting connections (sorry devs for hammering your server with requests, I promise I'll stop).
>The messaging system is pretty standard for a soulslike, not much else to say.