Set Negative Prompt In MetaData

ComfyUI bakes the whole workflow graph into your saved PNG, which is great for reproducing a run but useless if you want a human-readable "here's the negative prompt I used" the way Automatic1111 images carry it. This node writes exactly that: it stamps a negative prompt string into your image's metadata in the a1111-style png_info format, so tools and galleries that read A1111 metadata - and other people browsing your images - can actually see what you told the model to avoid.

You'd reach for this when you care about your outputs being legible outside ComfyUI. If everything you make lives and dies inside your own graph, you don't need it. If you post images, archive them, or want the metadata viewers in JNodes' own ImageDrawer (or any A1111-compatible tool) to show a proper negative field, this is how it gets there.

How it works

It's a metadata writer, not a prompt processor. Whatever text you hand it gets recorded as the negative-prompt entry in the generation's png_info. It doesn't touch your conditioning and doesn't affect the image the sampler produces - the negative that actually steers the model is whatever you wired into your CLIP encode and KSampler. This node's job is purely to make the record match, writing the string into the metadata that gets embedded when the image is saved.

That distinction matters: setting a negative here does not apply it to generation. It documents it. So the honest workflow is to feed this node the same negative text you fed your encoder, so the metadata tells the truth.

The inputs and outputs that matter

• prompt - the multiline negative-prompt text to write into metadata. Give it the same string your negative encode used.

The output is a BOOLEAN - effectively a success/confirmation flag you can chain into another metadata node or a boolean input to sequence operations. This is also an output node, so it does real work when the graph runs even without anything reading that boolean.

How to install it

ComfyUI Manager, search JNodes, install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/JaredTherriault/ComfyUI-JNodes
pip install -r ComfyUI-JNodes/requirements.txt

No model files involved.

Common issues & troubleshooting

The negative isn't in my saved file. Metadata gets embedded at save time, so this has to run as part of the graph that produces the saved image, and you need a saver that actually writes png_info. JNodes' own save nodes carry the metadata through; some third-party savers strip it. Check with a metadata viewer after saving, not before.

The metadata negative doesn't match what the image looks like. Expected - this node only writes the record. It does not feed the sampler. If the two disagree, it's because you fed this node different text than your encoder got. Wire them from the same source.

It's a distilled / CFG-1 model. Worth knowing that on distilled turbo models running at CFG 1 the negative prompt is skipped entirely during generation, so a documented negative there is a note-to-self at best. Restating what you don't want as a positive ("clean plain background") is the standard move on those models; the metadata negative is still fine to keep for provenance.