OutputGetString

Flux Continuum's whole pitch is one control interface driving many output modules - txt2img, img2img, inpainting, canny, depth, upscaling. Pick an output from the selector at the top left and the workflow reconfigures itself. The question is: how do the other nodes know which mode you picked? That's OutputGetString's job. It reads the name of the currently selected output and hands it out as a STRING, so anything downstream can branch on it.

How it works

The mechanism is cleverer than it looks, and it's borrowed from the set/get pattern popularized by KJNodes (the code even credits it). The Continuum workflow's "set" nodes carry titles that start with Output - - like Output - txt2img. This node watches that title, strips the Output - prefix, and emits the remainder as a string. Select "txt2img" in the interface, and OutputGetString outputs txt2img. Switch the selector, and the string changes.

In the shipped 1.7.0 workflow you'll see it doing exactly the load-bearing job: its output feeds a StringContains node and the ConfigurableModelRouter, which is how the workflow decides which generation module and model path to run for the current selection. It's the "what's the current mode?" sensor that the routing machinery reads.

The node is also marked as an output node (OUTPUT_NODE = True), which is a hint about how it's meant to be read - it's a way to expose a value, not transform one. There are no visible inputs to configure; it quietly does its thing based on node titles in the graph.

Why you'd reach for it

The obvious answer is conditional routing: you want one workflow that behaves differently depending on the selected output, and this gives you a plain string to compare against. But there's a second, sneakier use that's just as valuable: it's a debug window. When the workflow does something you don't expect, this node tells you exactly what output mode the graph thinks it's in. Mismatched mode names cause a surprising number of "why is it doing canny stuff when I asked for img2img" moments, and this makes the confusion visible.

Install

Ships with the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/robertvoy/ComfyUI-Flux-Continuum

Restart, or use ComfyUI Manager → search "Flux Continuum". The frontend part of the get/set system lives in the pack's web folder and loads automatically.

Troubleshooting

• Output is empty - there's no Output --prefixed set node to read, or the title format changed. The node looks for that exact prefix, so a renamed node breaks it.
• It returns the wrong mode - a second Output --prefixed node is confusing it; the original design even enforces a single instance per graph. Keep one.
• Missing node on workflow import - the pack didn't install cleanly; reinstall via Manager. And if the whole workflow shows missing nodes, grab the dependencies (Impact Pack, rgthree, Essentials, KJNodes) while you're in there.

It's a tiny node with a one-line trick, but in a workflow that reconfigures itself around your selection, that one line is how everything else knows where you pointed the interface.