ImpactBoolean

A node that outputs a single true-or-false value. You flip the toggle, it emits a BOOLEAN, and that's it. On its own it looks pointless - but it's the on/off pin for Impact Pack's little logic system, the thing that decides which branch a conditional takes or whether a loop keeps going.

Here's where it earns its place. ComfyUI's graph doesn't have an if statement; it just runs nodes. Impact Pack layers a thin logic system on top - conditional branches, loops, stop conditions - and every one of those needs a boolean to steer it. ImpactBoolean is how you supply that boolean by hand, or how you park one on a wire so several downstream nodes read the same switch. Toggle it once, and every branch reading it flips together.

How it works

It's a constant. Each execution it reads the toggle and passes that value straight through - no logic, no inversion, no side effects. If you want to compute a boolean rather than set one, that's a different node (ImpactCompare, ImpactIfNone, ImpactIsNotEmptySEGS and friends produce booleans from actual conditions). ImpactBoolean is the manual one: the master switch you flip yourself.

The input and output

• value (BOOLEAN, default false) - the toggle. True or false. There's nothing else to set.

Output is one BOOLEAN. It goes into the cond input of nodes like ImpactConditionalBranch / ImpactConditionalBranchSelMode (pick one of two values based on the flag) or ImpactConditionalStopIteration (stop a loop when true). It pairs naturally with ImpactFloat and ImpactInt - the three primitives you build logic graphs out of.

How to install it

You get it by installing Impact Pack, which is one download. Through ComfyUI Manager: search ComfyUI Impact Pack, Install, restart. Or by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Impact-Pack

then pip install -r requirements.txt inside ComfyUI's Python environment (portable builds use python_embeded\python.exe -m pip), and restart. The pack is ltdrdata's - the ComfyUI-Manager author - so it's mainstream and safe. A boolean toggle needs no models and no Subpack.

Common issues & troubleshooting

The trap isn't the node, it's the assumption. ImpactBoolean sets a value; it doesn't react to anything, so if you were hoping to test "is this SEGS empty" or "is A greater than B," this is the wrong node - reach for ImpactIsNotEmptySEGS or ImpactCompare, which output a boolean you can then feed into a branch. The other thing: the whole logic/loop family in Impact Pack is explicitly experimental, and loops in ComfyUI work by re-queuing the prompt rather than iterating inside one run. If a boolean-driven loop behaves oddly, that's usually the loop plumbing (order of execution, re-queue timing), not this node handing over the wrong flag.