SaveImage_motorway_edition

SaveImage_motorway_edition is the everyday save node, cloned from ComfyUI's built-in SaveImage and re-plumbed so it grabs its images from the Motorway bus instead of a wire. In a normal ComfyUI workflow, SaveImage is the node you hang off the end of a VAEDecode to write PNGs to ComfyUI/output/. In Motorway land, the images aren't on a wire - they're parked on the bus under a key - so this node reads that key, writes the PNG, and passes the bus along.

That "passes the bus along" part is the interesting bit. A stock SaveImage is a terminal node: it's marked OUTPUT_NODE, ComfyUI highlights it as the endpoint, and nothing flows out. This clone isn't flagged as an output node (the schema records is_output_node: false), so it writes the file but doesn't get the endpoint treatment, and the bus keeps flowing out of it. For a chain like "save a copy here, keep going and save something else later," that's actually handy. For matching stock behavior, it's a subtle difference you'll only notice if you rely on the output highlight.

The widgets are the familiar ones:

• filename_prefix (default ComfyUI) - the output name. The tooltip is worth reading because it's the author's own: it "may include formatting information such as %date:yyyy-MM-dd% or %Empty Latent Image.width% to include values from nodes." So you can build dynamic file names from other nodes' values - that's a real ComfyUI feature, not pack decoration.
• INPUT_images_key (default images) - the bus key your image batch lives under. Store your frames under any key upstream, type that name here, done.

Installing it

Part of ComfyUI_agilly1989_motorway. ComfyUI Manager: search ComfyUI_agilly1989_motorway, install, restart. Or:

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

No extra dependencies, no model files.

The catch

Two pack-level caveats. First, the clones ship disabled in release 1.1.7 - uncomment the two ClonedNodeMapping lines in custom_nodes/ComfyUI_agilly1989_motorway/__init__.py and restart, or this node won't be in your menu. Second, the README is candid that output nodes are among the motorway-edition ones that "won't work" - and here you can see why: the output-node flag isn't carried over, so it won't behave identically to stock. If your workflow's save needs to be bulletproof, keep the stock SaveImage; use this one when you want the entire pipeline, file-write included, living on the bus.