LuaEntity.created_tick

[sparr]

I specifically want to know whether an entity was created during the current tick, but more generally I'd like to know what tick each entity was created on. And I'd like access to that information when on_built_entity fires, for entities for which it hasn't fired yet.

[boskid]

No. What you are asking for is to have all entities hold extra 8 bytes of data that game does not need for anything but would need to save/load to avoid desyncs. 8 bytes of extra data on "each" entity (including trees and resource entities) is a lot of data: that would easily make save files take 2x their original size.

If you need this you have to store it on script side after an event.

This request feels like an XY problem where you asked for something that you think would help solve the problem but the request makes no sense and you did not tell what problem you are trying to solve.