As stated in documentation:
Keys are strings, typically enclosed by quotes for any given SDK.
taken from here
Does it mean that it is client limitation? For example my key is 64bit integer, as I understand I have to make it “human readable” string, like representing the number as string, or use more compact representation like encoding it as Base64, which still, will take more than just 8 bytes. So, why I cant store just raw bytes?