Save ConDelta

The README's own ELI5 walks you through using a ConDelta - make a models/ConDelta folder, copy in the sample files, wire up ApplyConDelta - but it doesn't say how a new one gets made in the first place. This node is that missing half. When the pack's own launch thread got asked how you "train" a ConDelta, the community answer was two native/pack nodes chained together: native ConditioningSubtract to compute the difference between two prompts, then SaveConditioningDelta to write the result to disk. After that, it shows up in the condelta dropdown on ApplyConDelta and LoadConditioningDelta like any of the pack's own sample deltas.

How it works

You feed it a conditioning_delta - the output of a subtract, an average, GetConDeltaFromPrompt, whatever you've built - along with a file_name to save it under. It writes the file, and from then on it's available anywhere the pack reads from your ConDelta model folder. This is a terminal node: it has no CONDITIONING output of its own, because its whole job is the write, not passing anything further downstream.

The inputs and outputs that matter

• conditioning_delta - the delta you want to persist.
• file_name - a plain string, what the saved file will be called.
• overwrite - default false. The tooltip states it plainly: "If true, will overwrite the file if it already exists." Leave it off while you're experimenting so you don't accidentally clobber an earlier attempt; turn it on deliberately once you're intentionally replacing a saved delta.

No outputs - this node is a sink, not something you chain further.

How to install it

Via ComfyUI Manager: search "ComfyUI-ConDelta", install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/envy-ai/ComfyUI-ConDelta

Before this node is useful, make sure the folder it's writing into exists: create ComfyUI/models/ConDelta (case sensitive) if you haven't already - the same folder ApplyConDelta and LoadConditioningDelta read from - then restart ComfyUI.

Common issues & troubleshooting

If overwrite is off and you re-save under the same file_name, expect the save to be refused rather than silently applied. That's a feature, not a bug - it protects an earlier saved delta from being clobbered by accident while you're iterating. If you genuinely want to replace it, flip overwrite on.

The new file should appear in ApplyConDelta's dropdown after a restart (or a node-list refresh, if your ComfyUI Manager setup supports it live). If it doesn't show up, double check ComfyUI/models/ConDelta actually exists and that the save didn't silently fail for some other reason (a bad path in file_name, for instance).

Build the delta with a real subtract, not a guess. The cleanest deltas come from subtracting two closely related prompts - the README's own example is "an art deco city" minus "a city" - or from this pack's GetConDeltaFromPrompt, which automates that comparison against a baseline. A delta saved from something less deliberate is more likely to carry noise you didn't intend.