API talk:2/characters/:id/inventory

bags is a list of available bag slots. So for an account that unlocked a expansion, bags will always contain at least 5 elements. Each represents a bag slot. If the bag slot is empty, the value is null. If a bag is in a bag slot, for that bag slot the appropriate object structure is stored. example: When the character has 5 bag slots and only one bag is equipped in the 2nd bag slot and every other bag slot is empty, the resulting list looks like this: null, object, null, null, null.