FK_简易图片合成编辑器

FK_简易图片合成编辑器 (simple image compositing editor) exists to kill the most annoying loop in ComfyUI: you nudge a foreground element a few pixels, then re-run the entire graph and wait. The author's pitch in the README is blunt - move the foreground, hit confirm, and only the nodes downstream of this one execute. He claims he hasn't seen another node do that, and honestly, the "confirm and continue without a full re-queue" behavior is rare enough that it's the whole reason to install this pack. If you composite foregrounds over backgrounds regularly, this is the node to reach for.

How it works

The node hands your background and foreground IMAGEs to a browser editor session served by the pack's local Node.js server. You drag, scale, and position the foreground over the background in the web UI. Clicking confirm returns two things: the composited image and a mask of where the foreground ended up. The token input keys the session - a default value ships with the node and works fine; change it if two editor sessions start stomping on each other.

Honest caveat: the actual implementation lives in an encrypted module. imgedit.py in this pack isn't source code, it's an AES-encrypted payload that decrypts and runs at import time, so you can't audit exactly how the "run downstream only" trick is wired. That's a real trust trade, not a hypothetical - the pack bundles obfuscated code alongside the genuinely useful nodes.

Inputs and outputs that matter

• background (IMAGE) - the canvas you're compositing onto.
• foreground (IMAGE) - the element you'll position. This is the one you'll fiddle with in the editor.
• foregroundMask (MASK, optional) - feed it if your foreground has transparency or you want clean edges.
• foreground2, foreground2Mask (optional) - a second stackable element, if you're compositing two things at once.
• Outputs: output (IMAGE) - the composite, ready to flow into a VAE encode, img2img, or a save node. Mask (MASK) - the composite mask, handy for an inpaint step or for cleaning edges downstream.

Install

Same pack-wide install, nothing node-specific:

cd ComfyUI/custom_nodes
git clone https://github.com/juehackr/comfyui_fk_server.git
pip install -r ComfyUI/custom_nodes/comfyui_fk_server/requirements.txt

Restart ComfyUI (or use ComfyUI Manager, searching the pack title). requirements.txt is just PyCryptodome and pybase64, and there are no model downloads and no API keys for this node. But it does need the Node.js side server, which the pack starts automatically on launch (and runs npm install into its server/ folder the first time).

Troubleshooting

• Editor UI won't open. The Node.js side server isn't running - check the ComfyUI terminal for FKServer: output and make sure Node is installed. This node is dead in the water without that server.
• Nothing happens on confirm. Make sure you're on the same session as the token the node is using, and that the workflow is queued at least once so the images reach the editor.
• Edits bleed into the background. You skipped the foreground mask. Composite with a mask if your subject has transparency; the "simple" in the name doesn't mean it reads your mind.

The obfuscation makes this the one node in the pack I'd be most careful with on a machine that matters. It's convenient, and a lot of people run it fine - but "encrypted node that spawns a server" is exactly the profile you should quarantine behind a venv first.