PreviewImage_motorway_edition

Every ComfyUI workflow ends the same way for most people: an image lands in the PreviewImage box and you look at it. This is that node, with one twist - instead of taking the image on a wire, it pulls it off the MOTORWAY 🚌💨 bus by key.

It's the most boring node in this pack, on purpose. PreviewImage is an output node: it shows you a batch of images and otherwise does nothing. Its only data input in the stock version is images, and its _motorway_edition form swaps that wire for a single key lookup:

• INPUT_images_key (default images) - the bus key holding the image batch you want to look at. If your upstream nodes parked the final render under IMAGE or output, change this to match, or the node shows nothing.

That's it. No other widgets, no outputs worth counting - the node returns the bus so you can keep it inline at the end of a chain, which is handy because you don't have to move the preview to the very end of the workflow to keep things flowing.

The one thing to remember: the images have to actually be on the bus under that key. In a bus workflow, a decoder or sampler's output only becomes visible here if an earlier node wrote it under a matching key.

Install

Pure code, no dependencies, nothing to download:

cd ComfyUI/custom_nodes
git clone https://github.com/agilly1989/ComfyUI_agilly1989_motorway

or via ComfyUI Manager under the pack title ComfyUI_agilly1989_motorway, then restart.

The fine print

PreviewImage is so trivial that the interesting facts here are all pack facts. This is a self-described beta - "IF THINGS BREAK ITS BECAUSE I BROKE IT" is in the README - and the _motorway_edition clones were auto-generated by a cloner that the 1.1.7 build disabled. On a current install the node may not exist; the core PreviewImage always does. If you're not committed to the bus, there is zero reason to prefer this edition.

And the classic bus error applies: KeyError: 'hash_...' doesn't exist in motorway means the key you typed was never stored - your image never got parked under images (or whatever you named it). Case-sensitive, silently overwriting on collision: the bus has no tolerance for sloppy key names.

If the box shows a blank image or nothing, check the key first, then check that whatever produced the image actually wrote to the bus before this node runs - node order on the bus matters.