Files
ComfyUI_frontend/src/lib/litegraph
AustinMroz d63b0f05bf Subgraph io fixes (#12281)
Fixes 3 different bugs when making links to and from subgraph IO from
vue nodes
- When dragging a link from a node to a subgraph IO, there is no
feedback if a slot is not a valid connection target or if a slot is
actively hovered
- When a link is made from a subgraph IO to a node, the reactivity is
not triggered on the node to indicate a change of link state.
- When dragging a link from a subgraph IO to a node, the link would not
snap to the valid connection targets on nodes
- The fix for this one is not as thorough as I would like. It only
allows connections to the slot, not connections to the hovered widget.
We have two deeply disconnected linking systems and properly reconciling
them would be a multi-week project.

Resolves FE-561

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-12281-Subgraph-io-fixes-3606d73d365081089f7ef19331c6d70a)
by [Unito](https://www.unito.io)
2026-05-20 10:26:47 -07:00
..
2026-05-20 10:26:47 -07:00
2026-01-27 17:59:19 -08:00

@ComfyOrg/litegraph

This is the litegraph version used in ComfyUI_frontend.

It is a fork of the original litegraph.js. Some APIs may by unchanged, however it is largely incompatible with the original.

Some early highlights:

Usage

This library is included as a git subtree in the ComfyUI frontend project at src/lib/litegraph.

litegraph.js

A TypeScript library to create graphs in the browser similar to Unreal Blueprints.

Description of the original litegraph.js

A library in Javascript to create graphs in the browser similar to Unreal Blueprints. Nodes can be programmed easily and it includes an editor to construct and tests the graphs.

It can be integrated easily in any existing web applications and graphs can be run without the need of the editor.

Node Graph

Features

  • Renders on Canvas2D (zoom in/out and panning, easy to render complex interfaces, can be used inside a WebGLTexture)
  • Easy to use editor (searchbox, keyboard shortcuts, multiple selection, context menu, ...)
  • Optimized to support hundreds of nodes per graph (on editor but also on execution)
  • Customizable theme (colors, shapes, background)
  • Callbacks to personalize every action/drawing/event of nodes
  • Graphs can be executed in NodeJS
  • Highly customizable nodes (color, shape, widgets, custom rendering)
  • Easy to integrate in any JS application (one single file, no dependencies)
  • Typescript support

Integration

This library is integrated as a git subtree in the ComfyUI frontend project. To use it in your code:

import { LGraph, LGraphNode, LiteGraph } from '@/lib/litegraph'

How to code a new Node type

Here is an example of how to build a node that sums two inputs:

import { LiteGraph, LGraphNode } from './litegraph'

class MyAddNode extends LGraphNode {
  // Name to show
  title = 'Sum'

  constructor() {
    this.addInput('A', 'number')
    this.addInput('B', 'number')
    this.addOutput('A+B', 'number')
    this.properties.precision = 1
  }

  // Function to call when the node is executed
  onExecute() {
    var A = this.getInputData(0)
    if (A === undefined) A = 0
    var B = this.getInputData(1)
    if (B === undefined) B = 0
    this.setOutputData(0, A + B)
  }
}

// Register the node type
LiteGraph.registerNodeType('basic/sum', MyAddNode)

Server side

It also works server-side using NodeJS although some nodes do not work in server (audio, graphics, input, etc).

import { LiteGraph, LGraph } from './litegraph.js'

const graph = new LGraph()

const firstNode = LiteGraph.createNode('basic/sum')
graph.add(firstNode)

const secondNode = LiteGraph.createNode('basic/sum')
graph.add(secondNode)

firstNode.connect(0, secondNode, 1)

graph.start()

Projects using it

ComfyUI

ComfyUI default workflow

Projects using the original litegraph.js

Click to expand

webglstudio.org

WebGLStudio

MOI Elephant

MOI Elephant

Mynodes

MyNodes

Feedback

Please open an issue on the GitHub repo.

Development

Litegraph has no runtime dependencies. The build tooling has been tested on Node.JS 20.18.x

Releasing

This library is embedded via git subtree in ComfyUI_frontend. Releases are managed through the parent repository's release process.

Contributors

You can find the current list of contributors on GitHub.

Contributors (pre-fork)

  • atlasan
  • kriffe
  • rappestad
  • InventivetalentDev
  • NateScarlet
  • coderofsalvation
  • ilyabesk
  • gausszhou