LayerUtility: Queue Stop

Ever want a workflow to just stop at a certain point - run the first half, look at the result, and not waste GPU time barreling into the expensive second half? QueueStop is that switch. Drop it in the graph and it can interrupt the current run right where it sits, or wave execution through, depending on how you set it. It's a debugging and gating tool, and once you've used it a few times you'll wonder why it isn't built in.

How it works

The node sits inline on a connection and, when it executes, either raises an interrupt that halts the queue or does nothing and passes the value along. Because it passes its input straight through to its output, you splice it into a live connection - say, right after the stage you want to inspect - and its position in the dependency graph decides when it fires.

The obvious use is a manual breakpoint: set it to stop, run, review the upstream output, then flip it to continue and run the rest. It's also handy as a gate in a graph you don't want auto-completing every time.

The place it really saves GPU time is a two-stage pipeline where the second half is expensive - a base generation followed by a heavy upscale, or a still followed by video. Splice QueueStop right after the cheap first stage, set it to stop, and you can iterate on your prompt and seed all day without ever paying for the upscale. Once a base result is worth keeping, flip to continue and let the pricey half run. It turns "generate everything every time" into "generate the cheap part until it's good, then commit."

The inputs and output that matter

• any - the value routed through it, so the node lands at the right spot in execution order. Whatever type you feed comes back out unchanged.
• mode - stop or continue. This is the master switch: stop arms the halt, continue makes the node a no-op pass-through.
• stop (default on) - the boolean that, together with mode, decides whether execution actually halts.

Output is any - the passed-through value, so you can keep wiring downstream (the downstream just won't run while it's stopping).

How to install it

ComfyUI Manager: search ComfyUI Layer Style, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/chflame163/ComfyUI_LayerStyle

install requirements.txt into ComfyUI's Python, restart. It's under 😺dzNodes → LayerUtility → SystemIO.

Common issues

The main confusion is that the halt is tied to when the node executes, which is tied to what depends on its output - not to where it looks on the canvas. If it's stopping too early or too late, check what's wired through it. And remember to flip mode back to continue (or toggle stop off) when you're done inspecting, or you'll sit there wondering why the workflow keeps ending halfway. It's a deliberate stop, not an error - a halted queue here means the node did its job.