Standard library for mcfunction

mcfstd is a library datapack for Minecraft Java Edition. It adds named integer variables, arithmetic, comparisons, callback helpers, and more on top of vanilla mcfunction commands.

The full documentation lives in the mcfstd wiki

# Set variable 'score' to 10
function var:set { k: "score", v: 10 }

# Add five
function var:math/add { k: "score", v: 5 }

# Check the result
function var:comp/eq { k: "score", v: 15 }
execute if function stdout:true run say score is 15
execute if function stdout:false run say score is not 15

Installation

Download the datapack zip from the releases page and place it directly inside your world's datapacks/ directory.

Reload the world:

reload

Enable the datapack if needed:

datapack enable "file/mcfstd-X-X-X.zip"

Replace X-X-X with the release version you installed.

Features

Feature	Summary	Documentation
Variables	Set, unset, copy, move, increment, decrement, and test integer variables	Variables
Arithmetic	Add, subtract, multiply, divide, and modulo variables	Arithmetic
Comparisons	Compare variables against integers or other variables	Comparisons
Function calls	Pass variable values into Minecraft macro functions	Function Calls
Standard output	Branch on the result of the previous boolean operation	Standard Output
Triggers	Register area enter/leave callbacks and block placement callbacks	Triggers
Debugging	Show scoreboards and receive trace output	Debugging

For a compact list of every public function, see the Function Reference.

Public Namespaces

Namespace	Purpose
var:	Integer variables and operators
call:	Call macro functions with variable values as arguments
trigger:	Area and block callbacks
stdout:	Read the boolean result of the previous comparison
debug:	Debug output and scoreboard display helpers

Functions under z_std: are internal implementation details. See Internal Model for how the datapack stores variables, tracks triggers, and manages macro call storage.

More Documentation

• Getting Started
• Function Reference
• Internal Model