How do you build a numistic shrine?

[Zabik]

As the title says - how? I saw one player having incredible trade values on his planets early on, almost as if he was a mega corp, while he was a regular empire. But if I try same civics, same traits, same ethics, it does not appear for me.

There is no specific tech this person researched, nor did he meet someone special to get those. (Only one were the caravenrs, but I double checked for him not to purchasing anything with their coins.)
So is this some sort of lucky event or what? Seens pretty op, giving you 2 priests worth of a holo-theatre and autochton monument in one building. Plus 2 merchants on top of it. Which boosts both the stability, production and trade.

 

[Terijian]

It is a deal/event offered by the caravaneers when they come through your space, no caravan coinz involved

I also got the event as either a hive or machine (cant recall) and it gave me a permanent flat buff (i think 5% to EC jobs) instead of a building