Compositor Config V4

CompositorConfig4 is the V4 equivalent of the V3 config node - the unglamorous feeder that turns up to 8 images (with optional masks) into the COMPOSITOR_CONFIG object the Compositor V4 canvas consumes. The V4 version adds two things V3 didn't have: explicit save-format and save-folder controls, and a slightly different masking path where masks are serialized to disk under fixed names like cfg{node_id}-mask1.png so they survive workflow reloads.

Connect its config output to Compositor4's config input. That's the whole wiring job.

What to actually set

• width / height - canvas size, your export resolution. 512 default, step 32. Set it to what you want out.
• padding - the parking zone around the export area (100 default). Drag assets out there to stash them or reach transform handles; the green border shows the real export region.
• normalizeHeight - force all inputs to one height, aspect preserved. Quick and dirty; can degrade quality.
• onConfigChangedContinue - the big one. Off (default) means the flow pauses so you can compose; on means it grabs a snapshot and continues. The author labels the on-state "Grab and Continue", and warns there is no real pause - with a random seed upstream this can loop.
• invertMask - flip alpha on all masks before they're applied.
• saveFormat - PNG Level 0 (fastest, the default) up to PNG Level 9 (smallest files), plus JPEG, WebP Lossless, and BMP. PNG is lossless and the safe choice; JPEG will drop your alpha.
• saveFolder - where the snapshot and masks live: temp (wiped on restart, won't survive reloads), input, or output (default, inside a compositor/ subfolder). If you want your composition to survive a browser refresh, don't use temp.

Then image1–image8 and mask1–mask8, all optional. Image order is z-order - image1 is the farthest back, image8 the frontmost.

Output: a single config socket. That's it.

Installing

Standard pack install - ComfyUI Manager, search "Compositor", pick erosDiffusion; or:

cd ComfyUI/custom_nodes
git clone https://github.com/erosDiffusion/ComfyUI-enricos-nodes.git

No model downloads, no extra pip packages.

Gotchas worth knowing

Masks here are applied in the config node (baked into RGBA) rather than left to the canvas, and a config signature hash - computed from every input including file hashes of the images and masks - is what tells the Compositor whether to stop and let you recompose. So changing anything on this node, even an image upstream, correctly triggers a pause. If you edit a workflow and the canvas suddenly demands attention, that's the signature changing, not a bug.

One practical trap: pick saveFolder deliberately. Images saved to temp don't survive reloads, and if your composition vanishes after a refresh, that's why. And keep the canvas sensible - 8 images at 4k each will choke both this node's file writes and the browser canvas.