Recipe | Ingredient

Ingredients are usually used to set one Item at a time, but they can contain multiple items.
To set multiple items, you can shift + right-click on the ingredient slot, and it will open the Ingredient Options menu.

Tags

Tags are groups of items for easier management of recipes.
The Tags Button will open the Tag settings to configure the tags and choose from a list of tags.

JSON

{
    "replaceWithRemains" : true,
    "allowEmpty" : false,
    "items" : [ /* Items that can be used in the ingredient slot */ ],
    "tags" : [ /* Item tags that are added to the list of items */ ],
}

Replace with Remains

This allows the item to be replaced by the vanilla crafting remains.
For example, lava/water/milk buckets will be replaced with empty buckets.
Enabled by default.

Allow Empty Ingredient

Can be enabled to mark the Ingredient as optional, and may be empty when crafting.
A use case could be to create complex recipes, that wouldn't otherwise be possible, together with Result Merge Adapters.
Please use this option carefully, it is very likely to interfere with other recipes!