vlo Logic Not

vlo Logic Not does one thing: it inverts a boolean. True becomes false, false becomes true, end of story. It's a one-line node, and it's exactly the kind of plumbing that feels like a joke until you need it - then you need it constantly.

Here's the pattern that makes it earn its place. ComfyUI's switch and gate nodes are built on a convention: optional inputs read None (or false) as "skip me," and booleans drive things like "keep this region" vs "let it go." The problem is that the polarity rarely matches what you want. Your detector outputs "this region is worth fixing" but your downstream gate is wired as "skip when true." Your sampler wants denoise_mask marked where to keep, your mask node marks where to change. Every one of those is a Not.

That's where the node shines in vlo's workflows: it sits between a condition and a gate so you don't have to re-think the whole graph's logic. Invert once at the point of use, keep the upstream node reading naturally.

What's on it

One input, one output:

• value (BOOLEAN) - the boolean to flip. Notably it's force_input, meaning there's no widget to type into; you must wire something into it. That's a feature - a Not node with a hand-typed toggle would just be a confusing way to set a constant.
• value (BOOLEAN, output) - not value.

Feed it a primitive boolean, a comparison result, a condition output from a switch or controller, and the inverted signal comes out the other side ready to drive whatever wanted the opposite polarity.

The honest caveat

It's ComfyUI, so you don't strictly need a node for this - the frontend lets you invert a lot of widgets with a right-click, and some controller packs expose an "invert" checkbox. But those are per-widget settings that hide in the inspector; a Not node is visible in the graph, which matters when you come back to a workflow three weeks later and can't remember why that gate was wired backwards. Small node, big legibility win.

Install

Part of ComfyUI-vlo, installed with the rest of the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/PxTicks/ComfyUI-vlo.git

Restart ComfyUI and it lands under utils/logic. No dependencies, no models, no keys - it's literally not value in a box.