Core Extensions

June 18, 2026 · View on GitHub

This directory contains the core extensions that provide essential functionality to the ComfyUI frontend.

Overview
Extension Architecture
Core Extensions
Extension Development
Extension Hooks
Further Reading

Overview

Extensions in ComfyUI are modular JavaScript modules that extend and enhance the functionality of the frontend. The extensions in this directory are considered "core" as they provide fundamental features that are built into ComfyUI by default.

Extension Architecture

ComfyUI's extension system follows these key principles:

Registration-based: Extensions must register themselves with the application using app.registerExtension()
Hook-driven: Extensions interact with the system through predefined hooks
Non-intrusive: Extensions should avoid directly modifying core objects where possible

Core Extensions List

The following table lists ALL core extensions in the system as of 2025-01-30:

Main Extensions

Extension	Description	Category
clipspace.ts	Implements the Clipspace feature for temporary image storage	Image
contextMenuFilter.ts	Provides context menu filtering capabilities	UI
dynamicPrompts.ts	Provides dynamic prompt generation capabilities	Prompts
editAttention.ts	Implements attention editing functionality	Text
electronAdapter.ts	Adapts functionality for Electron environment	Platform
groupNode.ts	Migrates deprecated group nodes to subgraphs on load	Graph
groupOptions.ts	Handles group node configuration options	Graph
index.ts	Main extension registration and coordination	Core
load3d.ts	Supports 3D model loading and visualization	3D
maskeditor.ts	Implements the mask editor for image masking operations	Image
nodeTemplates.ts	Provides node template functionality	Templates
noteNode.ts	Adds note nodes for documentation within workflows	Graph
previewAny.ts	Universal preview functionality for various data types	Preview
rerouteNode.ts	Implements reroute nodes for cleaner workflow connections	Graph
saveImageExtraOutput.ts	Handles additional image output saving	Image
saveMesh.ts	Implements 3D mesh saving functionality	3D
simpleTouchSupport.ts	Provides basic touch interaction support	Input
slotDefaults.ts	Manages default values for node slots	Nodes
uploadAudio.ts	Handles audio file upload functionality	Audio
uploadImage.ts	Handles image upload functionality	Image
webcamCapture.ts	Provides webcam capture capabilities	Media
widgetInputs.ts	Implements various widget input types	Widgets

Conditional Lines Subdirectory

Located in extensions/core/load3d/conditional-lines/:

File	Description
ColoredShadowMaterial.js	Material for colored shadow rendering
ConditionalEdgesGeometry.js	Geometry for conditional edge rendering
ConditionalEdgesShader.js	Shader for conditional edges
OutsideEdgesGeometry.js	Geometry for outside edge detection

Lines2 Subdirectory

Located in extensions/core/load3d/conditional-lines/Lines2/:

File	Description
ConditionalLineMaterial.js	Material for conditional line rendering
ConditionalLineSegmentsGeometry.js	Geometry for conditional line segments

ThreeJS Override Subdirectory

Located in extensions/core/load3d/threejsOverride/:

File	Description
OverrideMTLLoader.js	Custom MTL loader with enhanced functionality

Extension Development

When developing or modifying extensions, follow these best practices:

Use provided hooks rather than directly modifying core application objects
Maintain compatibility with other extensions
Follow naming conventions for both extension names and settings
Properly document extension hooks and functionality
Test with other extensions to ensure no conflicts

Extension Registration

Extensions are registered using the app.registerExtension() method:

app.registerExtension({
  name: 'MyExtension',

  // Hook implementations
  async init() {
    // Implementation
  },

  async beforeRegisterNodeDef(nodeType, nodeData, app) {
    // Implementation
  }

  // Other hooks as needed
})

Extension Hooks

ComfyUI extensions can implement various hooks that are called at specific points in the application lifecycle:

Hook Execution Sequence

Web Page Load

init
addCustomNodeDefs
getCustomWidgets
beforeRegisterNodeDef    [repeated multiple times]
registerCustomNodes
beforeConfigureGraph
nodeCreated
loadedGraphNode
afterConfigureGraph
setup

Loading Workflow

beforeConfigureGraph
beforeRegisterNodeDef   [zero, one, or multiple times]
nodeCreated             [repeated multiple times]
loadedGraphNode         [repeated multiple times]
afterConfigureGraph

Adding New Node

nodeCreated

Key Hooks

Hook	Description
`init`	Called after canvas creation but before nodes are added
`setup`	Called after the application is fully set up and running
`addCustomNodeDefs`	Called before nodes are registered with the graph
`getCustomWidgets`	Allows extensions to add custom widgets
`beforeRegisterNodeDef`	Allows extensions to modify nodes before registration
`registerCustomNodes`	Allows extensions to register additional nodes
`loadedGraphNode`	Called when a node is reloaded onto the graph
`nodeCreated`	Called after a node's constructor
`beforeConfigureGraph`	Called before a graph is configured
`afterConfigureGraph`	Called after a graph is configured
`getSelectionToolboxCommands`	Allows extensions to add commands to the selection toolbox

For the complete list of available hooks and detailed descriptions, see the ComfyExtension interface in comfy.ts.