Parameters

The Parameters node - "Simple Mustache Parameter Switcher" in the node menu - exists for one very specific, very real annoyance. When you export a ComfyUI workflow to API format for an external tool (the kind of thing ViewComfy and friends consume), the values you were going to change every run show up as mustache placeholders like {{prompt}} or {{seed}} buried in a wall of JSON. Editing them means opening the file, finding the right line, and hoping you don't paste the value into the wrong node. This node gives you a visible, editable spot on the graph to do that swap instead.

Here's the mechanism, which is simpler than the use case. You feed it three things:

• key - a label that only shows up in the console log. Name it after the variable it maps to so the printout stays readable.
• parameter - the placeholder string, e.g. {{prompt}}.
• test - the value you want substituted.

The logic: if parameter starts with { (i.e. it looks like a mustache placeholder), the node outputs test instead of the placeholder. Otherwise it passes parameter through untouched. That's the whole trick - it's a conditional substitution that turns "this needs a real value" into "here's the real value."

The output dropdown (String, Int, Float) decides which of the three return sockets actually fills in; the other two come back empty. Wire whichever one you need onward - Float into a denoise or an Empty Latent Image dimension, Int into a seed input, String into a text field.

A few honest notes. This is the thinnest of the three nodes in the pack, and it's aimed squarely at people automating ComfyUI, not at the typical drag-and-drop user. The parameter[0] == "{" check is also a bit crude - it fires on any string that starts with a brace, so don't put a normal value in parameter unless you want it swapped. And it prints everything (key, test, parameter, the resolved output) to your ComfyUI console, which is genuinely handy for confirming the mapping, but noisy if you leave it in a big graph.

Reach for it if you maintain a workflow that external tools call via the API. If you never export workflows to API format, you can skip this one without guilt - it's a developer convenience, not a creative tool.

Install

It ships in the same pack as the other two nodes. ComfyUI Manager → search "SimpleTools" and install "ComfyUI SimpleTools Suit", or clone it manually:

cd ComfyUI/custom_nodes
git clone https://github.com/celsojr2013/comfyui_simpletools

Restart ComfyUI. No model files to download, and this node needs no extra Python dependencies - the only dependency in the pack is googletrans, which exists for the translator node and can be ignored if you only use Parameters.