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Tags

Tags are JSON structures used in data packs to group related game elements together. They allow you to reference multiple items, blocks, entities, or other resources as a single unit. Tags are extensively used in commands, loot tables, advancements, recipes, and other data-driven features.

Basic Usage

Kore provides a generic tag function as well as specialized helper functions for each tag type:

// Generic tag with explicit type
tag<BlockTagArgument>("my_blocks", "block") {
	add(Blocks.STONE)
	add(Blocks.GRANITE)
	add(Blocks.DIORITE)
}

// Specialized helper function
blockTag("my_blocks") {
	add(Blocks.STONE)
	add(Blocks.GRANITE)
	add(Blocks.DIORITE)
}

This creates a tag file at data/<namespace>/tags/block/my_blocks.json.

Adding Values

There are several ways to add values to a tag:

Simple Addition

blockTag("building_blocks") {
	// Add a single block
	add(Blocks.STONE)
	
	// Using operators
	this += Blocks.COBBLESTONE
	this += "minecraft:granite"
	
	// Add with namespace
	add("custom_stone", namespace = "mymod")
}

Adding Other Tags

You can include other tags within a tag by prefixing with #:

blockTag("all_stones") {
	// Reference another tag
	add("#minecraft:stone_bricks", tag = true)
	
	// Or using the name/namespace form
	add("base_stone_overworld", namespace = "minecraft", tag = true)
}

Optional Entries

Mark entries as optional with the required parameter. Optional entries won't cause errors if they don't exist:

itemTag("optional_items") {
	add(Items.DIAMOND, required = true)  // Must exist
	add("mymod:custom_gem", required = false)  // Optional
	
	// Using TagEntry directly
	this += TagEntry("minecraft:emerald", required = false)
}

Replace Mode

By default, tags merge with existing tags of the same name. Set replace = true to completely override:

// This will replace the vanilla tag entirely
blockTag("logs", namespace = "minecraft", replace = true) {
	add(Blocks.OAK_LOG)
	add(Blocks.BIRCH_LOG)
	// Other logs won't be included
}

Tag Types

Kore provides specialized helper functions for all tag types. Here are the most commonly used ones:

Block Tags

blockTag("fragile_blocks") {
	add(Blocks.GLASS)
	add(Blocks.ICE)
	add(Blocks.GLOWSTONE)
}

Item Tags

itemTag("valuable_gems") {
	add(Items.DIAMOND)
	add(Items.EMERALD)
	add(Items.AMETHYST_SHARD)
}

Entity Type Tags

entityTypeTag("friendly_mobs") {
	add(EntityTypes.VILLAGER)
	add(EntityTypes.IRON_GOLEM)
	add(EntityTypes.CAT)
}

Function Tags

Function tags are special - they define groups of functions that can be called together or triggered by game events:

// Create functions to be tagged
function("on_load") {
	say("Datapack loaded!")
}

function("setup_scores") {
	scoreboard.objectives.add("kills", ScoreboardCriteria.PLAYER_KILL_COUNT)
}

// Tag them to run on load
functionTag("load", namespace = "minecraft") {
	add("on_load", namespace = name)
	add("setup_scores", namespace = name)
}

The minecraft:load and minecraft:tick function tags are special:

minecraft:load - Functions run once when the datapack loads
minecraft:tick - Functions run every game tick

Biome Tags

biomeTag("hot_biomes") {
	add(Biomes.DESERT)
	add(Biomes.BADLANDS)
	add(Biomes.SAVANNA)
}

Damage Type Tags

damageTypeTag("magic_damage") {
	add(DamageTypes.MAGIC)
	add(DamageTypes.INDIRECT_MAGIC)
	add(DamageTypes.DRAGON_BREATH)
}

Enchantment Tags

enchantmentTag("combat_enchants") {
	add(Enchantments.SHARPNESS)
	add(Enchantments.SMITE)
	add(Enchantments.BANE_OF_ARTHROPODS)
}

Fluid Tags

fluidTag("dangerous_fluids") {
	add(Fluids.LAVA)
	add(Fluids.FLOWING_LAVA)
}

Complete List of Tag Helpers

Kore provides helpers for all vanilla tag types:

Function	Tag Type	Path
`bannerPatternTag`	Banner patterns	`tags/banner_pattern`
`biomeTag`	Biomes	`tags/worldgen/biome`
`blockTag`	Blocks	`tags/block`
`catVariantTag`	Cat variants	`tags/cat_variant`
`configuredCarverTag`	World carvers	`tags/worldgen/configured_carver`
`configuredFeatureTag`	World features	`tags/worldgen/configured_feature`
`configuredStructureTag`	Structures	`tags/worldgen/structure`
`damageTypeTag`	Damage types	`tags/damage_type`
`enchantmentTag`	Enchantments	`tags/enchantment`
`entityTypeTag`	Entity types	`tags/entity_type`
`flatLevelGeneratorPresetTag`	Flat world presets	`tags/worldgen/flat_level_generator_preset`
`fluidTag`	Fluids	`tags/fluid`
`frogVariantTag`	Frog variants	`tags/frog_variant`
`functionTag`	Functions	`tags/function`
`gameEventTag`	Game events	`tags/game_event`
`instrumentTag`	Goat horns	`tags/instrument`
`itemTag`	Items	`tags/item`
`noiseSettingsTag`	Noise settings	`tags/worldgen/noise_settings`
`noiseTag`	Noise	`tags/worldgen/noise`
`paintingVariantTag`	Paintings	`tags/painting_variant`
`pigVariantTag`	Pig variants	`tags/pig_variant`
`placedFeatureTag`	Placed features	`tags/worldgen/placed_feature`
`pointOfInterestTypeTag`	POI types	`tags/point_of_interest_type`
`processorListTag`	Structure processors	`tags/worldgen/processor_list`
`structureTag`	Structures	`tags/worldgen/structure`
`templatePoolTag`	Jigsaw pools	`tags/worldgen/template_pool`
`trimMaterialTag`	Trim materials	`tags/trim_material`
`trimPatternTag`	Trim patterns	`tags/trim_pattern`
`wolfVariantTag`	Wolf variants	`tags/wolf_variant`
`worldPresetTag`	World presets	`tags/worldgen/world_preset`

Modifying Existing Tags

Use addToTag to append to an existing tag without creating duplicates:

// First creation
blockTag("my_ores") {
	add(Blocks.IRON_ORE)
	add(Blocks.GOLD_ORE)
}

// Later in code, add more entries
addToTag<BlockTagArgument>("my_ores", "block") {
	add(Blocks.DIAMOND_ORE)
	add(Blocks.EMERALD_ORE)
}

Using Tags in Commands

Tags can be referenced in commands with the # prefix:

function("clear_valuables") {
	// Clear all items matching a tag
	clear(allPlayers(), tag = ItemTagArgument("valuable_gems", name))
}

function("kill_hostiles") {
	// Kill entities matching a tag
	kill(allEntities {
		type = "#minecraft:raiders"
	})
}

Using Tags in Predicates

Tags work seamlessly with Predicates:

predicate("holding_tool") {
	matchTool {
		items(Tags.Item.PICKAXES)
	}
}

predicate("in_hot_biome") {
	locationCheck {
		biomes(BiomeTagArgument("hot_biomes", name))
	}
}

Using Tags in Recipes

Tags are commonly used in Recipes for flexible ingredient matching:

craftingShapeless("any_planks_to_sticks") {
	ingredient(Tags.Item.PLANKS)
	ingredient(Tags.Item.PLANKS)
	result(Items.STICK, 4)
}

Generated JSON

A basic tag generates JSON like this:

{
	"replace": false,
	"values": [
		"minecraft:stone",
		"minecraft:granite",
		"minecraft:diorite"
	]
}

With optional entries:

{
	"replace": false,
	"values": [
		"minecraft:diamond",
		{
			"id": "mymod:custom_gem",
			"required": false
		}
	]
}

With tag references:

{
	"replace": false,
	"values": [
		"#minecraft:stone_bricks",
		"minecraft:cobblestone"
	]
}

Best Practices

Use meaningful names: Name tags based on their purpose (e.g., mineable/pickaxe not pickaxe_blocks)
Leverage existing tags: Reference vanilla tags when appropriate instead of duplicating entries
Keep tags focused: Each tag should serve a single, clear purpose
Use optional entries: Mark modded content as required = false for cross-mod compatibility
Avoid replace when possible: Merging with existing tags maintains compatibility with other datapacks

Tags

Basic Usage

Adding Values

Simple Addition

Adding Other Tags

Optional Entries

Replace Mode

Tag Types

Block Tags

Item Tags

Entity Type Tags

Function Tags

Biome Tags

Damage Type Tags

Enchantment Tags

Fluid Tags

Complete List of Tag Helpers

Modifying Existing Tags

Using Tags in Commands

Using Tags in Predicates

Using Tags in Recipes

Generated JSON

Best Practices

See Also

External Resources

linkTags

linkBasic Usage

linkAdding Values

linkSimple Addition

linkAdding Other Tags

linkOptional Entries

linkReplace Mode

linkTag Types

linkBlock Tags

linkItem Tags

linkEntity Type Tags

linkFunction Tags

linkBiome Tags

linkDamage Type Tags

linkEnchantment Tags

linkFluid Tags

linkComplete List of Tag Helpers

linkModifying Existing Tags

linkUsing Tags in Commands

linkUsing Tags in Predicates

linkUsing Tags in Recipes

linkGenerated JSON

linkBest Practices

linkSee Also

linkExternal Resources

Tags

Basic Usage

Adding Values

Simple Addition

Adding Other Tags

Optional Entries

Replace Mode

Tag Types

Block Tags

Item Tags

Entity Type Tags

Function Tags

Biome Tags

Damage Type Tags

Enchantment Tags

Fluid Tags

Complete List of Tag Helpers

Modifying Existing Tags

Using Tags in Commands

Using Tags in Predicates

Using Tags in Recipes

Generated JSON

Best Practices

See Also

External Resources