⭐ Star Stop And Go

ComfyUI runs your whole graph top to bottom, and sometimes that's exactly the problem. You want to check an intermediate result - is this the right pose? Is the upscale worth continuing? - before committing to the expensive tail of the pipeline. Star Stop And Go is a physical pause button you drop into the graph: execution reaches it, shows you what's flowing through, and waits for you to click GO or STOP before continuing. If you've ever watched a 20-minute video render burn on because the first pass came out wrong, you know why this node exists.

How it works

It sits on a wire like a passthrough. Any input type connects (it uses a wildcard proxy, so IMAGE, LATENT, MODEL - whatever), and the value passes through to the output when you let it proceed. But before that happens, three modes decide what to do:

• User Select - execution halts and waits for a GO/STOP decision. If timeout_seconds (default 300) passes without you clicking, it auto-continues. This is the "give me a minute to look at it" mode.
• Pause - auto-continues after pause_seconds. A timed breath, not a decision point.
• Bypass - passes straight through, no stopping. This is the mode you leave it in when the workflow is proven and you don't want it interrupting every run.

For images there's a preview_image toggle that shows the intermediate frame right on the node while you decide. And empty_vram_ram is a nice extra: when enabled it unloads models and clears the cache before proceeding, showing memory usage before/after - genuinely handy when a long pipeline has left VRAM cluttered and you want a clean slate for the next stage.

Inputs and outputs

Inputs: mode, then the optional any_input (the passthrough), pause_seconds, timeout_seconds, preview_image, and empty_vram_ram. Output: a single output socket carrying the value through.

Installing

It's in the StarNodes pack:

cd ComfyUI/custom_nodes
git clone https://github.com/Starnodes2024/ComfyUI_StarNodes
cd ComfyUI_StarNodes
pip install -r requirements.txt

Restart, search star under ⭐StarNodes/Helpers And Tools. ComfyUI Manager users can search "Starnodes".

Where people get burned

The big one: this is a blocking node in a single-threaded pipeline. If ComfyUI's queue is running headless or you're rendering in the background, a workflow stuck at User Select just sits there until the timeout kicks in - there's no one around to click GO. For unattended batch runs, set mode to Bypass or rely on the timeout. Also, the STOP decision stops that branch by design, but the rest of the graph may have already executed, so "STOP" here means "don't continue this path," not "cancel the whole queue." Once you internalize that, it's the best manual quality-gate in the pack.