Thread:Nakano15/@comment-25946298-20150123174118/@comment-25946298-20160115201700

You use dedicated software to turn the Terraria.exe into source code, and there you can find all items and their number codes. You just have to know where to look in the files, since Terraria consists of some hundred thousands lines of code if I remember correctly. Terraria is written in C# which is easy to reverse engineer, unlike some other languages.