Unfortunately, the material requirements are a complex beast. We don't provide them on item/talent grid definitions because we can't know until what requirements it will have until the item is instantiated: so if you're looking at the item definition, that's why there's not much useful there. For the material requirements on an item, try the Get Inventory Item Detail endpoint - it has a "talentNodes" property that, for every talent node, has a "materialsToUpgrade" property that shows exactly what you need and how much for that instance of the item. We don't return it in the "get all items" service because it is a lot of data, and those services already return a ton of information (that most users don't need to see unless they drill into details). Keeping it out of the results that return multiple items saves everyone a lot of bandwidth and pain for the majority of use cases that don't need to know that info... but admittedly at the expense of not knowing this info upfront if you do happen to have a use case. In those cases, make the detail call! Hopefully this helps!