Negative Prompt

NegativePrompt is the least exciting node in the ComfyUI-SkyReels-A2 pack, and that's the point. It's a type-tagged text box: you type a negative prompt, it wraps it in a NEGATIVEPROMPT object, and that's the entire job. There's no API call, no hidden processing, no sampling. If you've used Wan-family models you'll recognize the shape of the default it ships with - it's a long list of the usual suspects plus video-specific ones like "static", "still picture", "subtitles" and "JPEG compression residue", tuned by Skywork for this model.

You need this node for the unglamorous reason that A2VideoGenerator won't accept a raw string. The pack defined custom data types (PROMPT for the positive, NEGATIVEPROMPT for the negative) so that a workflow can't silently miswire a text box into the model. The node exists to satisfy that type contract, nothing more.

What to set

One input: input_negative_prompt. The default is genuinely good for this model - Wan 2.1–based generators drift toward static frames and compression artifacts at low resolution, and the shipped list targets exactly that. Unless you have a specific artifact you're fighting, leave it alone. That's not laziness; it's one of those cases where the model author's default beats your guess.

Where it goes

The single output, negative_prompt, wires straight into the negative_prompt input on A2VideoGenerator, alongside the prompt output from the sibling A2Prompt node. It does nothing outside this pack - don't expect to feed it into a standard ComfyUI KSampler or a Wan wrapper; those want ComfyUI-native conditioning.

Installing it

It comes with the whole pack, so install Yuan-ManX/ComfyUI-SkyReels-A2 once: ComfyUI Manager → search "SkyReels", or

cd ComfyUI/custom_nodes
git clone https://github.com/Yuan-ManX/ComfyUI-SkyReels-A2.git
cd ComfyUI-SkyReels-A2
pip install -r requirements.txt

Restart after installing, and remember the pack needs the SkyReels-A2 model downloaded separately - this node is pure string handling, so it works the moment the pack imports, but the generator it feeds won't until LoadA2Model has a real pipeline.

Gotchas

The classic failure is pasting in a downloaded workflow where this node is missing - ComfyUI will report the NEGATIVEPROMPT input on the generator as unsatisfied, and the Manager won't always auto-find the right pack. Since the node is so thin, there's genuinely nothing else to troubleshoot: if the text isn't showing up in your generations, you've wired it to the wrong input, not misconfigured the node.