HtmlCraft API
HTML/CSS GUI Rendering Engine for Minecraft 1.20.1 Forge / Fabric and 26.2 Fabric
Introduction
HtmlCraft API is a lightweight HTML/CSS rendering engine that brings web frontend technologies into Minecraft GUI development. Instead of learning the complex Minecraft GUI API (GuiGraphics, Widget, AbstractContainerScreen, etc.), developers can build beautiful game interfaces by simply writing HTML + CSS.
Features
| Feature | Description |
|---|---|
| HTML Parsing | Common HTML tags, attributes, nested structures, HTML entities (named/decimal/hex) |
| CSS Styling | Class selectors, ID selectors, tag selectors, inline styles |
| Layout Engine | Block layout, Flexbox, CSS Grid |
| Visual Effects | Linear gradients, border radius, shadow simulation, opacity |
| Interaction | Button click events, mouse wheel scrolling, hit testing |
| Template Engine | {{variable}} replacement, data binding context |
| Thread Safety | ConcurrentHashMap, CopyOnWriteArrayList |
Requirements
This API ships in three versions. Pick the jar matching your loader and Minecraft version.
Forge Version (1.20.1)
| Dependency | Version |
|---|---|
| Minecraft | 1.20.1 |
| Forge | 47.x |
| Java | 17 |
Fabric Version (1.20.1)
| Dependency | Version |
|---|---|
| Minecraft | 1.20.1 |
| Fabric Loader | >=0.19.3 |
| Fabric API | 0.92.11+1.20.1 |
| Java | 17 |
Fabric Version (26.2)
| Dependency | Version |
|---|---|
| Minecraft | 26.2 |
| Fabric Loader | >=0.19.3 |
| Fabric API | 0.156.0+26.2 |
| Java | 25 |
Installation
As a Mod Dependency
- Forge 1.20.1: place
htmlcraftapi-1.0.0-1.20.1forge.jarinto themodsfolder - Fabric 1.20.1: place
htmlcraftapi-1.0.0-1.20.1fabric.jarinto themodsfolder - Fabric 26.2: place
htmlcraftapi-1.0.0-26.2fabric.jarinto themodsfolder
As a Development Dependency
Forge version (Mojang mappings):
dependencies {
implementation files('libs/htmlcraftapi-1.0.0-1.20.1forge.jar')
}
Fabric version (Yarn mappings, with Loom composite build):
dependencies {
modImplementation 'com.htmlcraft.api:htmlcraftapi:1.0.0-1.20.1fabric'
}
For Fabric, includeBuild is recommended to bring in the source project for debugging:
// settings.gradle (1.20.1)
includeBuild '../HtmlCraftAPI/fabric'
// settings.gradle (26.2)
includeBuild '../HtmlCraftAPI/fabric/26.2'
Quick Start
Examples below use Forge (Mojang mappings) API. The Fabric 1.20.1 version only differs in class names (e.g.
Component→Text,Minecraft→MinecraftClient,GuiGraphics→DrawContext). The Fabric 26.2 version refactors the internal render layer (GuiGraphics→GuiGraphicsExtractor), but the public HTML/CSS API is identical.
1. Create a Screen via Builder
import com.htmlcraft.api.HtmlRendererAPI;
import com.htmlcraft.api.binding.DataContext;
import com.htmlcraft.api.screen.HtmlScreen;
import net.minecraft.network.chat.Component;
DataContext data = new DataContext();
data.set("title", "My Interface");
data.set("content", "Hello, Minecraft!");
HtmlScreen screen = HtmlRendererAPI.createScreen(Component.literal("My Screen"))
.html("<div class='container'>" +
" <h1>{{title}}</h1>" +
" <p>{{content}}</p>" +
" <button id='btn-ok'>OK</button>" +
"</div>")
.css(".container { padding: 20px; background: #1a1a2e; border-radius: 10px; }" +
"h1 { color: #e94560; font-size: 16px; }" +
"p { color: #ffffff; }" +
"#btn-ok { background: #0f3460; color: #ffffff; border-radius: 6px; padding: 8px; }")
.data(data)
.onClick(event -> {
if ("btn-ok".equals(event.element().getId())) {
System.out.println("Player clicked the OK button");
}
})
.build();
Minecraft.getInstance().setScreen(screen);
2. Extend HtmlScreen for Custom Screens
public class MyScreen extends HtmlScreen {
public MyScreen() {
super(Component.literal("My Screen"));
}
@Override
protected String getHtml() {
return "<div class='root'>Custom content</div>";
}
@Override
protected String getCss() {
return ".root { padding: 16px; background: #2d2d44; }";
}
}
3. Forge / Fabric Mapping Reference
| Forge (Mojang) | Fabric (Yarn) | Description |
|---|---|---|
net.minecraft.network.chat.Component |
net.minecraft.text.Text |
Text component |
net.minecraft.client.Minecraft |
net.minecraft.client.MinecraftClient |
Client instance |
net.minecraft.client.gui.GuiGraphics |
net.minecraft.client.gui.DrawContext |
Draw context |
net.minecraft.world.level.saveddata.SavedData |
net.minecraft.world.PersistentState |
Save persistence |
net.minecraft.network.FriendlyByteBuf |
net.minecraft.network.PacketByteBuf |
Network buffer |
net.minecraftforge.network.SimpleChannel |
ServerPlayNetworking / ClientPlayNetworking |
Network channel |
Core API
HtmlRendererAPI
Unified entry point providing a Builder pattern for creating HTML Screens.
| Method | Description |
|---|---|
createScreen(Component title) |
Create a Screen builder |
HtmlRendererAPI.Builder
Chained builder for configuring HTML, CSS, data, and events.
| Method | Description |
|---|---|
html(String html) |
Set HTML content |
css(String css) |
Set CSS stylesheet |
data(DataContext context) |
Set template data context |
onClick(Consumer<ClickEvent> handler) |
Set click event callback |
build() |
Build the HtmlScreen instance |
HtmlScreen
Abstract HTML rendering screen base class, extends Minecraft Screen.
| Method | Description |
|---|---|
getHtml() |
Abstract method, subclass provides HTML content |
getCss() |
Override to provide CSS styles |
setClickHandler(Consumer<ClickEvent>) |
Set click event handler |
setPreferredSize(int w, int h) |
Set content area size (centered layout) |
rebuild() |
Rebuild render pipeline (refresh after data changes) |
getRootLayout() |
Get layout root node |
getPipeline() |
Get render pipeline |
HtmlScreen.ClickEvent
Click event containing the clicked element and coordinates.
| Method | Description |
|---|---|
element() |
The clicked DOM element |
button() |
Mouse button (0=left, 1=right, 2=middle) |
x() / y() |
Click coordinates |
DataContext
Template variable context, thread-safe.
| Method | Description |
|---|---|
set(String key, Object value) |
Set a variable |
get(String key) |
Get a variable |
getString(String key) |
Get string value |
has(String key) |
Check if variable exists |
clear() |
Clear all variables |
HtmlElement
DOM element node.
| Method | Description |
|---|---|
tagName() |
Get tag name |
getId() |
Get id attribute |
hasClass(String) |
Check if has class |
getAttribute(String) |
Get attribute value |
children() |
Get child nodes |
Supported CSS Properties
Layout
| Property | Values |
|---|---|
display |
block / flex / inline / grid / none |
flex-direction |
row / column |
justify-content |
flex-start / center / flex-end / space-between / space-around |
align-items |
flex-start / center / flex-end / stretch |
gap |
Pixel value |
grid-template-columns |
repeat(N, 1fr) |
Box Model
| Property | Description |
|---|---|
width / height |
Pixel value, auto |
padding |
Pixel value |
margin |
Pixel value |
border-width |
Pixel value |
Visual Effects
| Property | Values |
|---|---|
background |
#RRGGBB / #AARRGGBB / #RRGGBBAA |
background (gradient) |
linear-gradient(to bottom, #color1, #color2) |
color |
Text color |
border-color |
Border color |
border-radius |
Corner radius in pixels |
box-shadow |
offsetX offsetY blur spread #color |
opacity |
0.0 - 1.0 |
Text
| Property | Values |
|---|---|
font-size |
Pixel value |
text-align |
left / center / right |
Position & Overflow
| Property | Values |
|---|---|
position |
static / relative / absolute / fixed |
overflow-x / overflow-y |
visible / hidden / scroll / auto |
z-index |
Integer |
Template Engine
Use {{variable}} placeholders in HTML. They are replaced by TemplateEngine.render() with values from DataContext during init().
DataContext data = new DataContext();
data.set("player_name", "Steve");
data.set("level", 30);
// HTML template
String html = "<div>Player: {{player_name}} | Level: {{level}}</div>";
Special characters are automatically escaped to HTML entities to prevent injection.
Render Pipeline
HTML String
↓
HtmlParser (parse to DOM tree)
↓
StyleSheet + CssParser (load CSS rules)
↓
StyleCalculator (compute final styles per element)
↓
LayoutEngine (perform layout, generate LayoutNode tree)
↓
RenderPipeline (generate and execute render commands)
↓
GuiGraphics (draw to Minecraft screen)
Package Structure
com.htmlcraft.api
├── HtmlCraftAPI.java // Mod main class
├── HtmlRendererAPI.java // Public entry point + Builder
├── core/
│ ├── HtmlDocument.java // HTML document
│ ├── HtmlElement.java // DOM element node
│ ├── HtmlNode.java // DOM node interface
│ └── HtmlText.java // DOM text node
├── parser/
│ ├── HtmlParser.java // HTML parser
│ └── CssParser.java // CSS parser
├── style/
│ ├── StyleSheet.java // CSS stylesheet
│ ├── StyleCalculator.java // Style calculator
│ └── ComputedStyle.java // Computed style
├── layout/
│ ├── LayoutEngine.java // Layout engine
│ └── LayoutNode.java // Layout node
├── render/
│ ├── RenderPipeline.java // Render pipeline
│ ├── RenderContext.java // Render context
│ ├── RenderCommand.java // Render command interface
│ └── commands/ // Concrete render commands
│ ├── FillRectCommand.java
│ ├── DrawTextCommand.java
│ ├── DrawBorderCommand.java
│ └── BlitTextureCommand.java
├── binding/
│ ├── DataContext.java // Data binding context
│ └── TemplateEngine.java // Template engine
└── screen/
└── HtmlScreen.java // HTML rendering screen base class
Click Events
Clickable elements include:
<button>tags<a>tags- Any element with an
idattribute
Clicks trigger a ClickEvent callback. Use event.element().getId() to identify which element was clicked.
Scroll Support
Elements with overflow-y: scroll or overflow-y: auto automatically respond to mouse wheel scrolling. Each scroll step moves 20 pixels.
License
LGPL-2.1
Author
Yifei

