MoCHI Reference (experimental)

MoCHI is experimental (how files are written and what is generated may change in later versions). MoCHI is a markup language that describes objects placed in a VRChat world in .mochi.xml and generates a prefab when you save in Unity (you can write positions, prefabs, components, and repetition driven by images or table rows).

Page

Page	Description
Syntax overview	Categories of elements, how tags map to GameObjects, parts and props, values fixed at generation time and values that change at runtime, expansion order, name scope
Element reference	For each element: syntax, where it can be placed, allowed children, attributes, what it creates, the name when name is omitted, errors
Value grammar	EBNF and diagnostic numbers for numbers, Vector3, Color, bool, paths, bindings, data, static, and enumerations
Setup and generation	Files and parts, entry points, generation on save, handling of generated files, checks before Play and upload
Props and identity	How props are passed, identity and key
Components and prefabs	Components, material copies, changes inside a prefab, <Slot> content, mount points
Component list	Categories of components you can write, value types, asset references, and components you can’t write
Physics components	Attributes of Rigidbody, colliders, joints, and more
Rendering components	Attributes of renderers, Light, Camera, particles, and more
Audio components	Attributes of AudioSource, reverb, and Audio Filters
UI components	Attributes of Canvas, Image, Button, layout groups, and more
TextMeshPro components	Attributes of TextMeshPro, TextMeshProUGUI, and more
VRChat components	Attributes of VRCPickup, VRCObjectSync, VRCMirrorReflection, and more
Other components	Attributes of Animator, constraints, NavMesh, and more
Layout	size and pivot, how <Row> and <Grid> arrange children, part size
Part with a T# script	Generated <Name>.Mochi.cs, runtime props, two-stage generation
inspect	Arguments when passing mochi to the MCP inspect tool, and the JSON it returns
Errors	List of diagnostic codes, and examples that are errors

Package

Where it ships	The same Unity package as TsukimiSharp (T#). You don’t need to install a separate package for MoCHI.
Relationship to T#	Write a script in T# only when you give a part behavior while the world runs (Part with a T# script). If you build only with parts that have no script, you don’t need to write any T# code
Checking from AI	Pass the mochi argument to the MCP server’s inspect (inspect).

Minimal example

Assets/Gallery/Gallery.mochi.xml

<Gallery prefab="true">
  <Object name="Wall" position="0 1.5 4" rotation="0 180 0">
    <For each="art" in="folder('art/')">
      <Frame key="{art.key}" image="{art.file}" position="0 0 0"/>
    </For>
  </Object>
</Gallery>
<!-- file: Assets/Gallery/Frame.mochi.xml -->
<Frame>
  <Props>
    <Prop name="image" type="Texture"/>
  </Props>
  <Object name="Canvas">
    <MeshFilter mesh="builtin:Quad"/>
    <MeshRenderer material="../Art/Frame.mat" mainTexture="{image}"/>
  </Object>
</Frame>

Piece	Purpose
prefab="true"	An attribute that marks this file as the source for generating a prefab. This file becomes the entry point.
<Object>	Creates one GameObject.
<For each="art" in="folder('art/')">	Repeats its content for each image in the art/ folder.
<Frame …/>	Places the part Frame (Frame.mochi.xml).
{art.file}	A binding that reads the file column of the repetition row.
<Props>	Declares the values (props) the part receives.
<MeshRenderer … mainTexture="{image}"/>	Adds a component. Writing mainTexture copies the .mat and sets the image on it.

How to read it

Notation	Meaning
Examples starting with samples/	Examples that don’t error, and reach prefab generation.
Examples starting with rejected/	Examples that are errors. The diagnostic code they produce is noted in the text.
<!-- file: … -->	Marks a file boundary in an example. The first file is the entry point, and paths are relative to the project root.
Statements with no example	Content that can’t be checked by whether it errors, such as generation behavior inside Unity.

Assets the examples reference

The examples reference the following 6 assets.

Path	Contents
Assets/Kit/KitFrame.prefab	Under root KitFrame: Canvas (MeshFilter and MeshRenderer), Plate (with Label under it), Mount.
Assets/Kit/KitRoom.prefab	Under root KitRoom: Floor, Mount1, WallEast (with Mount0 and Mount3 under it), Mount2, Door.
Assets/Art/Frame.mat	A material using the Standard shader.
Assets/Gallery/art/01_Sea.png	Image
Assets/Gallery/art/02_Moon.png	Image
Assets/Data/art.csv	Columns are id, file, title. There are 2 rows, sea and moon, and file points to the two images above.