ImageOnlyCheckpointSave_motorway_edition

If ImageOnlyCheckpointLoader is the "read" side of image-only checkpoints, this is the "write" side. ImageOnlyCheckpointSave_motorway_edition bundles a diffusion model, a CLIP vision encoder and a VAE into a single image-only checkpoint file - the format used by image-conditioned models like Stable Zero123. It's stock ComfyUI's ImageOnlyCheckpointSave, wrapped for the MOTORWAY 🚌💨 pipe in agilly1989/ComfyUI_agilly1989_motorway.

Where the normal node takes three model wires, this one reads all three out of the pipe by key, writes the file to disk, and passes the pipe along. It's the save-node variant of the family, so unlike most of its siblings it has no output keys - nothing comes back out of it except the Motorway itself.

Inputs that matter

• INPUT_model_key (default "model") - pipe key of the diffusion model
• INPUT_clip_vision_key (default "clip_vision") - pipe key of the vision encoder
• INPUT_vae_key (default "vae") - pipe key of the VAE
• filename_prefix (STRING, default "checkpoints/ComfyUI") - the output path relative to ComfyUI/models/

The model, clip vision and VAE all have to be in the pipe under exactly those keys - if any of them was stored under a different string, you'll get the pack's signature "key doesn't exist" error. This is a merge-and-save tool, so the realistic use case is: you merged or fine-tuned an image-only model, kept the pieces in the pipe, and now you want a single reusable checkpoint file you can load later.

How it works

Standard clone mechanics: pop the Motorway, pull the three components out by their key strings, run stock ImageOnlyCheckpointSave with filename_prefix, then return a cloned pipe. Saving doesn't produce a return value beyond the pipe - the action happened on disk. It's the inverse of the pack's ImageOnlyCheckpointLoader_motorway_edition, so the two make a tidy round-trip.

Installing

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

Restart ComfyUI, or search "motorway" in ComfyUI Manager. Pure Python, no requirements.txt - no downloads, though saving one of these files can be multi-GB, so check disk space first.

Gotchas

Three things. Keys are exact and case-sensitive - a 'MotorwayClass' object has no attribute 'hash_' error means one of "model", "clip_vision" or "vae" was never written to the pipe. Watch the case trap: read keys default to lowercase, and nothing in this pack's defaults uses uppercase for these reads, so don't typo them. And the family caveat: it's BETA, with the motorway_edition clones disabled in the 1.1.7 hotfix - if it's not in your menu, stock ImageOnlyCheckpointSave is the same node with wires.