CheckpointSave_motorway_edition

Most ComfyUI sessions end with an image. CheckpointSave is for the much rarer session that ends with a model - when you've merged or modified a checkpoint in the graph and want to write the result back to your models/checkpoints folder as a .safetensors. This is its Motorway-ed clone: instead of wiring model, clip and vae into the save node, you tell it which Motorway keys hold them, and it writes everything to disk.

How it works

The wrapper pulls three things out of the Motorway by key and saves them as one checkpoint file:

• INPUT_model_key - key for the model to save (default model)
• INPUT_clip_key - key for the CLIP (default clip)
• INPUT_vae_key - key for the VAE (default vae)
• filename_prefix - the save location, default checkpoints/ComfyUI. In ComfyUI convention that means models/checkpoints/ComfyUI.safetensors, and any folder you add to the prefix becomes subdirectories under models/checkpoints.

The node instantiates the real core CheckpointSave, runs it with the pulled artifacts, and returns the Motorway so the chain can keep going. The only visible output is MOTORWAY 🚌💨 - the node's real "output" is the file it writes.

When you'd actually use it

Only in a model-merging context. If you've been blending checkpoints or patching weights in the graph and you're happy with the result, this is the save step that turns your experiment into something you can load next week. Note the defaults: the pack assumes you stored your stuff under model, clip, vae - if your chain used the loader's default keys (MODEL, CLIP, VAE), change these to match, because a key that was never written throws the signature 'MotorwayClass' object has no attribute 'hash_' error. Case matters in this pack.

A word of caution that has nothing to do with the Motorway: saving checkpoints is how people end up sharing models they don't have the rights to. Merged weights inherit the licenses of their parents, so check what your source checkpoints actually permit before you start distributing anything you export. The community has burned itself on this repeatedly.

Motorway specifics

MOTORWAY 🚌💨 is required here (the original node has connection inputs, so the generator made it so). Your chain starts at a MotorwayStart or primitive starter, and the save is a natural end-of-line step - there's no reason to wire anything after it except to keep the graph tidy.

Install

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

Restart, or search "ComfyUI_agilly1989_motorway" in ComfyUI Manager. No pip dependencies, no model downloads - the pack ships nothing but the Motorway class and its generated wrappers.

Fine print

This is an explicitly-beta pack (README opens "BIG BROKEN WITH ASYNC WILL FIX WHEN I GET THE TIME/MOTIVATION"), and the current hotfix release has the _motorway_edition clone generation commented out of __init__.py, so on the newest main these nodes may not load at all. An old workflow referencing them that comes up with missing nodes is hitting exactly that. One more pack-specific note: the README warns that output-style nodes and ones with custom JS are the least likely to survive the generated family - save nodes are the borderline case, so test on a throwaway model before you trust it with something you care about. GitHub issues are the way to report problems; the author's Discord DMs are, by his own admission, ignored.