ComfyUI_frontend Copy and paste node isn't working.

Problem

Copy and paste functionality stops working after switching from legacy LiteGraph nodes to Vue nodes via keybinding. The issue demonstrates a broader interaction state management problem during mode transitions.

https://github.com/user-attachments/assets/d381cd78-7e31-4615-b78e-ff25fb91e579

Sequence:

Legacy mode: Copy/paste works normally
Switch to Vue nodes via Experimental.ToggleVueNodes keybinding
Vue mode: Copy/paste completely broken

Root Cause

DOM Event Target Mismatch: The useCopy and usePaste composables fail to detect valid targets when Vue nodes are active.

Copy Detection Logic (useCopy.ts:23-30):

const isTargetInGraph =
  e.target.classList.contains('litegraph') ||
  e.target.classList.contains('graph-canvas-container') ||
  e.target.id === 'graph-canvas'

if (isTargetInGraph && canvas?.selectedItems) {
  canvas.copyToClipboard()  // Never executes in Vue mode
}

Problem: When Vue nodes are active, DOM focus shifts to Vue component elements that don't have the required classes/IDs, so isTargetInGraph returns false.

Technical Analysis

Mode Switching Works Correctly

Vue node toggle: useCoreCommands.ts:299-309
Selection sync: Vue nodes properly call canvas.select() and update canvas.selectedItems
State management: Mode transitions preserve graph state correctly

Event Handling Breaks

Legacy mode: LiteGraph canvas handles copy/paste directly
Vue mode: Relies on Vue composables with DOM target detection
Failure point: Target detection logic doesn't account for Vue component DOM structure

Selection System Comparison

Legacy Mode:

Selection handled by LGraphCanvas.select()/deselect()
Copy/paste handled by canvas event listeners
Target always matches #graph-canvas

Vue Mode:

Selection handled by useNodeEventHandlers composable
Copy/paste handled by separate Vue composables
Target becomes Vue component elements (no required classes)

Reproduction

Load any workflow in legacy mode
Select and copy a node (Ctrl+C) - works
Press keybinding for Experimental.ToggleVueNodes command
Try to select and copy nodes - fails silently
Same issue affects paste (Ctrl+V)

Solution

Fix DOM target detection to work with Vue node elements:

Option 1: Expand Target Detection

const isTargetInGraph =
  e.target.closest('.litegraph') ||
  e.target.closest('.graph-canvas-container') ||
  e.target.closest('#graph-canvas') ||
  e.target.closest('[data-vue-node]')  // Vue node container

Option 2: Use Canvas Focus State

const canvas = canvasStore.canvas
const isCanvasFocused = document.activeElement?.closest('.graph-canvas-container')
if (isCanvasFocused && canvas?.selectedItems) {
  canvas.copyToClipboard()
}

Option 3: Unified Event Handling

Move copy/paste handling to a layer that works consistently across both modes.

Files Affected

useCopy.ts:23-30 - Broken target detection
usePaste.ts:41-44 - Same issue
Vue node components - Need consistent DOM structure/classes

Impact

This affects all keyboard shortcuts that use similar DOM target detection, not just copy/paste. Users lose core functionality when switching to Vue nodes.

After further investigating the issue, I discovered: If the workflow from which nodes are copied has been saved at least once to the file system, then copying from it to an unsaved new workflow using CTRL+V is impossible – only CTRL+SHIFT+V works. However, you still need to Left-Click the canvas at least once beforehand.

Demonstration (the key moment is at 0:35 – I save the workflow and then try to copy something from it to a new unsaved workflow):

https://github.com/user-attachments/assets/96ea7a26-e8c2-457b-8c54-193450a74626

After saving the workflow to the file system, no matter what I copy from it, nothing can be pasted into other workflows using the standard CTRL+V shortcut. Only CTRL+SHIFT+V works, and even then, only after clicking the canvas.

There are a number of other oddities and problems with copying and pasting that are difficult for me to explain (for example, sometimes copying via CTRL+V can suddenly work when copying from a saved workflow to an unsaved one, but this doesn't always work) - you can see everything in the video.

Sep 28 '25 13:09 Shyryp

https://github.com/user-attachments/assets/c2b6f1e1-0d9a-4cdd-a4e3-cc4b88e670f7

I still can't reproduce the same issue. I just downloaded the latest Portable and tested it. I'm not sure what happened on your end. Have you ever tried to reproduce the same issue on another computer?

Sep 28 '25 14:09 comfyui-wiki

Screen.Recording.2025-09-28.at.22.05.16.mov I still can't reproduce the same issue. I just downloaded the latest Portable and tested it. I'm not sure what happened on your end. Have you ever tried to reproduce the same issue on another computer?

I tested it on four of my PCs.

Here's a video from my other PC, but on Windows 11 (Nvidia RTX 3060):

https://github.com/user-attachments/assets/aab1a97c-1db1-4422-923b-8fa3c99f96fc

In the video, on this other computer, I'm using the freshly unpacked latest release version of ComfyUI (link above). I didn't modify or update anything—I just launched it.

This problem isn't limited to my PCs; some of my friends are experiencing it too.

~~Could it be affected by having multiple keyboard layouts on the system? My friends and I each have two or three keyboard layouts. On my main PC I have keyboard layout "English (United State)", "English (Europe)", "Russian". On my PC from this video: "English (United State)", "Russian".~~ UPD: Having multiple keyboard layouts on a system doesn't affect this. A system with a single layout will still experience this issue.

In the videos, I only used the US English (United State) keyboard layout.

UPD2: Another user has the same problem - https://github.com/comfyanonymous/ComfyUI/issues/8481#issuecomment-3344151809

Sep 28 '25 16:09 Shyryp

@Shyryp Finally, I got what you mean now. However, since the issue you reported isn't related to the current one, I have submitted a feature request for you. If you want to track the progress of this feature support, you can leave any comment in this issue: https://github.com/Comfy-Org/ComfyUI_frontend/issues/5844

Sep 29 '25 03:09 comfyui-wiki

I solved this problem by adding group and select nodes in the group then ctrl+c then ctrl+v to paste

Nov 29 '25 02:11 vlatkan

close it for now as it should fix in https://github.com/Comfy-Org/ComfyUI_frontend/pull/7103 and https://github.com/Comfy-Org/ComfyUI_frontend/pull/7166. Please feel free to reopen if it still exists after these changes

Dec 08 '25 17:12 jtydhr88

Copy and paste node isn't working.

Problem

Root Cause

Technical Analysis

Mode Switching Works Correctly

Event Handling Breaks

Selection System Comparison

Reproduction

Solution

Option 1: Expand Target Detection

Option 2: Use Canvas Focus State

Option 3: Unified Event Handling

Files Affected

Impact

Related