iOS in-app purchase metadata

I am about to create my first iOS app with in-app purchase. I read documentation and everything, but I can't find anywhere how to append some metadata to in-app purchase object. I would like to add some ad开发者_运维技巧ditional information to each item, like category, sub-title e.t.c.

iBooks uses this for category, author and other stuff, so it should be possible. I presume they are using in-app purchase in iBooks, is that correct?

Only solution I came up with so far is to have all metadata on my server and retrieve them when items from store load. Is there any other way?

I need to add new items (and possibly new metadata) after app is online, so I can't put them inside app

Nope. That's what you're supposed to do. Metadata and the like is entirely up to you, and Apple provides no inbuilt mechanism in StoreKit or iTunes Connect for supplying it.