While I can edit books' author metadata in the list view, I can’t seem to be finding a way to set multiple authors for a single title. Is there any way to do this, so that I can have, let's say, two separate author entities for a book?

defaults read ~/Library/Containers/com.apple.BKAgentService/Data/Documents/iBooks/Books/Books.plist

      BKAllocatedSize = 131072;
      BKDisplayName = "An Introduction To Software Architecture";
      BKGeneratedItemId = 409BAEEB1FD9D2272D63E97BFB7CDEBD;
      BKGenerationCount = 3;
      BKInsertionDate = 558100869;
      BKIsLocked = 0;
      artistName = "David Garlan, Mary Shaw";
      explicit = 0;
      isPreview = 0;
      itemName = "An Introduction To Software Architecture";
      metadataMigrationVersion = 20140106;
      modificationDate = "2000-11-13 17:55:48 +0000";
      pageCount = 42;
      path = "/Users/Sepehr/Library/Mobile Documents/iCloud~com~apple~iBooks/Documents/An Introduction To Software Architecture.pdf";
      releaseDate = "2000-11-13 12:55:48 +0000";
      sourcePath = "/Users/Sepehr/Books/An Introduction To Software Architecture.pdf";
      updateDate = "2000-11-13 17:55:48 +0000";
      versionNumber = 0;

How can I get more than one author added in the metadata for an iBooks document?

  • 1
    Kindly edit the question to clearly specify your query.
    – Nimesh Neema
    Sep 22, 2018 at 14:00
  • 3
    I don’t get the close votes. This is pretty clearly asking about how to edit the filesystem metadata for files that the books reader will use. Please flag this for reopening if it somehow gets closed and an edit to explain your OS requirements doesn’t get it reopened.
    – bmike
    Sep 22, 2018 at 14:44
  • 1
    If I understand your question correctly you are struggling with defining several authors for an iBook. Yet your code example shows only a read command and properties with several authors included. What have you tried to define several authors?
    – nohillside
    Sep 22, 2018 at 15:57
  • I'm sorry for not being clear enough. That's exactly what I want to do; multiple authors for a book. So that I can have those authors as separate authors in the Authors tab. I tried different formattings, using semicolons, commas, etc. But it seems to be updating that artistName key as just a string. Also tried updating ePub files using Calibre to no avail.
    – user87
    Sep 22, 2018 at 17:46
  • So you basically want several artistName entries in the metadata structure? Not sure this is even possible (keys must be unique), do you have an example of an iBook where it is defined as such?
    – nohillside
    Sep 23, 2018 at 8:08

1 Answer 1


All this metadata exists on the filesystem, so you could use the xattr command line to change pretty much anything, but I find the documentation and syntax to be very challenging to get and use.

I would start by trying xattred editor and perhaps the easier tools SearchKey / SearchKeyLight

The author has a very superb blog explaining why the app was made in the first time and how to use it as well if you don’t get the buttons or features. Think of all these metadata as a key value store. You just name the attribute (like modification date) and then set a value (today’s date or whatever). Same for page count and in your case, the author metadata string type.

Since you are reading the overall catalog, I would focus on changing the metadata in each book one by one (perhaps working on a throwaway ebook or duplicate copy of a book if you don’t have a good backup and restore procedure for the books you store in iCloud).

  • To give you an update, there's this com.apple.iBooks.author#S xattr attribute on iBooks epub/pdf files which is of type String. I don't think I can change to something like a multivalue key, or to create a duplicate key. I also tried the app you suggested, no way there as well. It only allows you to edit the string content of the key as string.
    – user87
    Sep 22, 2018 at 21:54
  • And trying to set a duplicate attr, obviously overwrites the previous value. xattr -w "com.apple.iBooks.author#S" "Another author here" "Design Patterns Elements of Reusable Object-Oriented Software.epub".
    – user87
    Sep 22, 2018 at 21:55

You must log in to answer this question.