Files
ComfyUI_frontend/src/lib/litegraph
Alexander Brown 067d80c4ed refactor: migrate ES private fields to TypeScript private for Vue Proxy compatibility (#8440)
## Summary

Migrates ECMAScript private fields (`#`) to TypeScript private
(`private`) across LiteGraph to fix Vue Proxy reactivity
incompatibility.

## Problem

ES private fields (`#field`) are incompatible with Vue's Proxy-based
reactivity system - accessing `#field` through a Proxy throws
`TypeError: Cannot read private member from an object whose class did
not declare it`.

## Solution

- Converted all `#field` to `private _field` across 10 phases
- Added `toJSON()` methods to `LGraph`, `NodeSlot`, `NodeInputSlot`, and
`NodeOutputSlot` to prevent circular reference errors during
serialization (TypeScript private fields are visible to `JSON.stringify`
unlike true ES private fields)
- Made `DragAndScale.element.data` non-enumerable to break canvas
circular reference chain

## Testing

- All 4027 unit tests pass
- Added 9 new serialization tests to catch future circular reference
issues
- Browser tests (undo/redo, save workflows) verified working

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8440-refactor-migrate-ES-private-fields-to-TypeScript-private-for-Vue-Proxy-compatibility-2f76d73d365081a3bd82d429a3e0fcb7)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>
2026-01-29 18:18:58 -08:00
..
2026-01-27 17:59:19 -08:00
2026-01-27 17:59:19 -08:00
2026-01-27 17:59:19 -08:00
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

Use GitHub actions to release normal versions.

  1. Run the Release a New Version action, selecting the version increment type
  2. Merge the resolution PR
  3. A GitHub release is automatically published on merge

Pre-release

The action directly translates Version increment type to the pnpm version command. Pre-release ID (suffix) is the option for the --preid argument.

e.g. Use prerelease increment type to automatically bump the patch version and create a pre-release version. Subsequent runs of prerelease will update the prerelease version only. Use patch when ready to remove the pre-release suffix.

Contributors

You can find the current list of contributors on GitHub.

Contributors (pre-fork)

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