Preview Flake Data

PreviewFlakeData is the debugging node you'll wish you'd added earlier. The whole Flakes design hides a lot behind one flake_data wire - a model, a CLIP, a VAE, two conditionings, a latent, a resolution, sampler settings, filename state - and when something comes out wrong, the first question is "what is actually in that bundle?" This node answers it. Feed it a flake_data pin and it opens a modal showing four panels: Models (checkpoint name, VAE, text encoder, and each LoRA with its strength), Prompts (the positive split by BREAK, and the negative), Parameters (steps, cfg, sampler, scheduler), and Metadata (resolution, filename prefix).

The key design detail is that it's a pass-through - the flake_data output carries the bundle onward unchanged. So it's not a terminal you bolt on at the end; you can splice it inline, mid-chain, and keep the graph working. Stick one after your model preset to confirm the checkpoint and defaults loaded right. Stick another after a Flake Stack to see how the LoRAs merged and what the BREAK-joined prompt actually looks like before you render. It's the "print the receipt" node in a pack that's otherwise happy to hide the receipt.

It also surfaces a few things you can't see by squinting at the graph. The LoRA list comes from the bundle's metadata, so you can verify strengths actually applied in the right order. The positive prompt is shown split by BREAK, which makes it obvious when a flake's fragment got swallowed or duplicated. And the filename prefix shows the real composed output path - preset name, stems, and all - so you can catch a typo'd output_stem before it mails a folder's worth of files to the wrong place.

One honest caveat: it's an output-style node (ComfyUI marks it OUTPUT_NODE), so it's meant to be looked at, and its value is entirely in the frontend modal. The backend just reads the bundle and formats the panels. That also means it's one of the more frontend-dependent nodes in a young pack - if the modal ever looks wrong after a ComfyUI update, the data underneath is still fine; the JS is just rendering it.

Inputs and outputs. Required: flake_data. Output: flake_data (identical to the input). No generation, no modification.

Install. ComfyUI Manager → search ComfyUI Flakes → Install, or:

cd ComfyUI/custom_nodes
git clone https://github.com/JeyzerMC/comfyui-flakes

then restart. PyYAML is the only dependency and it ships with ComfyUI core.