Save (Full Pipe)

Save (Full Pipe) is the end of the line for a full-pipe workflow: it takes the image out of the pipe, writes it to disk, and embeds both ComfyUI workflow data and A1111-style metadata. The A1111 half is the headline. The author's stated motivation is that pulling a prompt out of a ComfyUI workflow isn't standardized anywhere, but A1111's parameters text chunk is - so this node writes the prompt, negative, seed, sampler, and settings in a format other tools actually read.

That's a real quality-of-life gap it closes. ComfyUI embeds its workflow JSON in PNGs by default, but that's a graph, not a prompt. If you've ever dropped a ComfyUI render into A1111 or a metadata reader and gotten nothing useful, this node is the fix. It's also why the pack's prompt nodes bother to store positive_text and negative_text in the pipe's meta - this node consumes them.

How it works

It pulls the image from the pipe (or an optional image input), resolves the output path and filename, and saves each frame. The filename and path fields support variables: %date, %time, %model, %width, %height, %seed - so %time_%seed (the default prefix) gives you a unique file every run without collisions. Batch images get an _0000, _0001… suffix.

For metadata:

• a1111_metadata (on) - builds an A1111 parameters string from the pipe's meta: the prompt/negative text, seed, sampler, steps, CFG, resolution, and the checkpoint name. It even maps ComfyUI sampler names to their A1111 equivalents, which is the fiddly bit most homebrew savers get wrong.
• comfyui_workflow (on) - embeds the workflow JSON and prompt. PNG only - the node is explicit that workflow embedding happens just for the png extension.

Inputs that matter

• extension - png / jpg / jpeg / webp. PNG keeps both metadata kinds; JPG gets the A1111 string but not the workflow.
• filename_prefix and path - both support the variables above. path defaults to %date, so outputs land in output/2026-08-16/ style subfolders.
• show_preview (on) - controls whether the image shows in the UI after saving.

Output: the image itself, passed through. It's an output node, so it can end the chain.

Installing

Part of the mudknight utils pack. ComfyUI Manager → search comfyui-mudknight-utils, or:

cd ComfyUI/custom_nodes
git clone https://github.com/mudknight/comfyui-mudknight-utils

Restart ComfyUI. No model downloads.

Gotchas

• Prompt is "unknown" in the metadata - the checkpoint name comes from the pipe's meta.ckpt_name, which the Loader (full-pipe) sets. If you built the pipe with a plain CheckpointLoader and FullPipePack, that meta key never gets populated, so save falls back to unknown. Use the pack's loader, or set the meta yourself.
• Prompt text missing from A1111 metadata - the prompt nodes store positive_text/negative_text in meta. If you're encoding conditioning some other way, there's nothing to write.
• Workflow not embedded on JPG - expected; it's PNG-only by design.
• Empty image error - the node returns "No image in pipe" if neither the pipe nor the optional input has an image. Feed the image input.

Zero comfy.icu impressions, small pack - but if A1111-compatible metadata is your requirement, this is the only node in the pack that finishes the job properly.