Have ITooltipProvider inherit IValid Updated Bolt recipe to provide 2x Bolt per craft Check for IsValid() in CustomTooltip to determine if the tooltip should fuck off Item definitions are always valid Added RecipeCategory enum and add a property for it on RecipeResource Added the first fully working version of the crafting interface https://files.facepunch.com/conna/1b2511b1/sbox-dev_PTQgHsDnTd.mp4