CraftScript reference

Every keyword, operator, function and member available.

Keywords

Keyword	Use
let / var / const	Declare variables (const can't be reassigned).
fun	Named functions and lambdas fun(x) { }.
class, extends, this, super	Classes and inheritance.
enum	Enumerations.
import, from, as	Modules.
if, else, while, for … in, break, continue, return	Control flow.
and, or, not (or &&, ||, !)	Logic.
true, false, null	Literals.
mod, item, block, recipe	Content declarations.
ore, tree, patch, structure, biome, dimension, terrain, biome_map, carver	World generation declarations. See World generation and Generation by code.
on … priority	Event handler.
command … requires … alias … describe	Commands.
every, after + ticks/seconds/minutes	Timers.

Comments: // line, # line, /* block */. Statements are separated by line breaks (or ;).

Operators

Operator	Meaning
+ - * / %	Arithmetic. + concatenates if one side is a string; it also joins lists.
== != < <= > >=	Comparison. An id and a string are equal if they represent the same id.
= += -= *= /=	Assignment.
??	Default value if the left side is null.
?.	Safe access: returns null instead of failing.
a..b	Inclusive range of numbers.
x[i]	List index (negative counts from the end), map key, string character.

Falsy values: null, false, 0, "", empty list or map.

Built-in functions

Function	Description
print(...)	Writes to the server log.
log(...)	Same as print, with the mod name.
str(x)	Converts to a string.
num(x)	Converts to a number (or null).
int(x)	Integer part.
round, floor, ceil, abs, sqrt	Math.
min(...), max(...)	Minimum/maximum of numbers.
sin, cos, atan2, pi()	Trigonometry, in radians.
len(x)	Length of a string, list or map.
type(x)	Name of the type.
is(x, Class)	Checks a class or enum.
random(), random(n), random(a, b)	Decimal 0–1, integer 0–n, integer a–b.
chance(p)	true with probability p (0–1).
pick(list)	Random element.
now()	Current milliseconds.
id("ns:path")	Creates an identifier.
item(id, count?, name?)	Creates an ItemStack.
color(text)	Converts & into color codes.
broadcast(msg)	Message to all players.
run(command)	Runs a game command as the console. Escape hatch: the command format belongs to the game and can change.
player(name)	Online player or null.
players()	List of players.
world(id?)	World (the overworld by default).
mod_loaded(id)	Is another mod loaded?
config(name, values?, synced?)	Declares or reads a mod settings file.
listen(channel, fun(data, player))	Receives data on a mod channel.
send(player, channel, data)	Sends data from the server to a player.
send_to_server(channel, data)	Sends data from the client to the server.
server	The server.
tick	Current tick.
game_version, namespace	Minecraft version and the mod namespace.

String members

length, upper(), lower(), trim(), contains(s), starts_with(s), ends_with(s), split(sep), replace(a, b), repeat(n), substring(from, to?), is_empty.

List members

size, is_empty, first, last, add(x)/push(x), remove(x), remove_at(i), contains(x), index_of(x), join(sep), reverse(), sort(), clear(), map(f), filter(f), each(f), any(f), all(f), sum().

Map members

keys(), values(), has(k), get(k, default?), remove(k), size; plus direct access with map.key or map["key"].

Game objects

Names use snake_case (max_health) and are the same members as in Kotlin (maxHealth). Enums are used as strings (player.game_mode = "creative"). Details for each one in The world and players.

Type	Properties	Methods
Player	name, uuid, health, max_health, food_level, game_mode, inventory, held_item, is_op, is_sleeping, has_crafting_client, location, world, custom_name, is_alive, data	send, action_bar, title, give, set_held_item, play_sound, teleport, heal, damage, has_permission, kick, set_rotation, add_tag, has_tag, set_cooldown, has_cooldown
World	id, players, time, is_raining, data	block_at, set_block (with optional states), spawn, drop_item, explode, strike_lightning, spawn_particle, play_sound, light_at, container_at, set_sign_text, set_chunk_loaded, entities, living_near, shoot, summon
Block	type, x, y, z, world, location, is_solid, data	set_type, relative
Entity	uuid, type, world, location, custom_name, is_alive, data, direction, vehicle	teleport, remove, set_rotation, add_tag, has_tag
LivingEntity	everything in Entity, health, max_health	damage, heal, set_ai, add_effect, remove_effect, has_effect, effects, add_modifier, remove_modifier, attribute, set_attribute, equipment, set_equipment
Inventory	size	get, set, add, count, clear
Location	world, x, y, z, yaw, pitch, block_x, block_y, block_z	add, distance_to
data (store)	keys; data["key"] reads and writes	get, set, get_int, get_number, get_string, get_boolean, remove, clear
ItemStack	item, count, name, lore, data, enchantments	with_count
Server	players, worlds, motd, tps, is_dedicated	player, world, broadcast, stop, run_command

World generation objects

What the functions of a world generation declaration receive while chunks are made. Explained on the Generation by code page.

Object	Properties	Methods
world (structure build)	x, y, z, seed, min_y, max_y	block, state, is_air, is_in, can_stay, set (with optional states), inside, surface, top, flow, structures, place_file
plan (structure plan)	chunk_x, chunk_z, seed, min_y	height, biome, column, file_size
site (structure build)	x, y, z, radius, min_y, max_y, data, seed
world (terrain)	seed, min_y, height	biome
world (biome_map)	seed	tagged
ctx (carver)	seed, start_x, start_z, chunk_x, chunk_z, min_y, max_y	carve
at (biome surface)	x, y, z, depth_above, depth_below, surface_depth, steep	noise

Command argument types

player, int, number, bool, string (one word), text (the rest of the line), id. Add ? to make it optional.

Limits

• 2,000,000 steps per invocation (event, command or timer).
• 200 nested calls (recursion).
• Ranges of up to 1,000,000 elements.