Originally Posted by kovidgoyal
every book in calibre is assigned a unique uuid (the only way these can be duplicated is if the user does something unusual like manually creating duplicate libraries). It should be unique enough for your purposes.
Is this uuid accessible as a calibre variable or would the opf file (metadata.opf in book dir?) need to be read in and searched?
The other concern I would have is that if this, f207657a-2b88-4763-95db-f37c0e536782, is an example of aforesaid uuid, it would create filenames much longer than I had in mind. Perfect for internal usage but no more meaningful to a user than my current basic calibre_covernn
I think I might be trying to overthink this. The functionality of this cosmetic plugin is not internal to calibre, so I don't think precise rocket science is required as yet.
I really appreciate you techies joining in though