Setting another object property?

[Chung_Xa]

@hexdump2002

I have tried to use property.set on the bullet from the weapon, but it needs an url to the object and I have an id (the id that is returned when the bullet is created with a factory).

I found this thread may give you the answer
How to get url instead of id from factory.create() (SOLVED) - Questions - Defold game engine forum

@hexdump2002

how can I make the bullet know about the weapon it has created it to be able to message the weapon about collision or call the needed script function directly from the bullet?

I think you should store its weapon in somewhere (eg. a lua table), so that you can refer it to get all info you need