modeling-app/docs/kcl-std/modules/std.md

---
title: "std"
subtitle: "Module in std::"
excerpt: "The KCL standard library "
layout: manual
---

The KCL standard library 

Contains frequently used constants, functions for interacting with the KittyCAD servers to create sketches and geometry, and utility functions. 

The standard library is organised into modules (listed below), but most things are always available in KCL programs. 

You might also want the [KCL language reference](/docs/kcl-lang) or the [KCL guide](https://zoo.dev/docs/kcl-book/intro.html). 

## Modules

* [`appearance::appearance`](/docs/kcl-std/modules/std-appearance)
* [`array`](/docs/kcl-std/modules/std-array)
* [`math`](/docs/kcl-std/modules/std-math)
* [`sketch`](/docs/kcl-std/modules/std-sketch)
* [`solid`](/docs/kcl-std/modules/std-solid)
* [`sweep::sweep`](/docs/kcl-std/modules/std-sweep)
* [`transform`](/docs/kcl-std/modules/std-transform)
* [`turns::turns`](/docs/kcl-std/modules/std-turns)
* [`types`](/docs/kcl-std/modules/std-types)
* [`units::units`](/docs/kcl-std/modules/std-units)

## Functions and constants

* [`END`](/docs/kcl-std/consts/std-END)
* [`START`](/docs/kcl-std/consts/std-START)
* [`X`](/docs/kcl-std/consts/std-X)
* [`XY`](/docs/kcl-std/consts/std-XY)
* [`XZ`](/docs/kcl-std/consts/std-XZ)
* [`Y`](/docs/kcl-std/consts/std-Y)
* [`YZ`](/docs/kcl-std/consts/std-YZ)
* [`Z`](/docs/kcl-std/consts/std-Z)
* [`assert`](/docs/kcl-std/assert)
* [`assertIs`](/docs/kcl-std/assertIs)
* [`clone`](/docs/kcl-std/functions/std-clone)
* [`helix`](/docs/kcl-std/functions/std-helix)
* [`offsetPlane`](/docs/kcl-std/functions/std-offsetPlane)
* [`patternLinear2d`](/docs/kcl-std/patternLinear2d)