Is there something like an player metadata ?

[Sires]

Every time I have ideas about mods that needs to store information in the player, but I don't know how to save data in the player, is there any metadata of the player, or I need to save all the informations about the player in node metadatas ?

[rubenwardy]

Player meta data does not currently exist, although it's hopefully going to soon

You should save player metadata into a new file in the world using io.open and minetest.serialize

[hajo]

I have ideas about mods that needs to store information in the player,
but I don't know how to save data in the player

To store infos, you could use items, like books/signs/chests.