Float Param

The interesting sliders in ComfyUI are almost all floats: CFG scale, denoise strength, LoRA weights. And the ones you want to control from an API are exactly those. Float Param is the pack's decimal input node - one FLOAT widget, one matching output, and nothing else, which is the entire point of a pack built for parameterizing workflows.

It takes a single value input (default 1.0) and passes it straight through as a value output. Wire it into a KSampler's cfg or denoise, a LoraLoader's strength_model and strength_clip, a scale factor on an upscaler - anywhere a decimal number belongs. The node does zero processing; the value you type (or your backend sends) is the value downstream nodes receive.

The range and step to remember

The widget is bounded to -100 to 100 with a step of 0.01. That's a generous window - every realistic CFG, denoise, or LoRA strength fits comfortably - and the 0.01 step is fine granularity for sliders. But it's worth knowing the bounds exist, because they're enforced in the UI. If you ever need a value beyond ±100, this widget won't let you type it; you'd fall back to a math node or a raw float constructed another way.

The min: -100 also means negatives are allowed, which is worth contrasting with the sibling ParamInt (floor of 0). If you need a negative number anywhere, this is the param node to reach for.

Same pattern as the rest of the pack

Like every Param node here, the value that matters for an API setup is the node title. Rename the node (right-click → Title) to the parameter name your backend will use - cfg, denoise, lora_strength - save the workflow in API format, and have your service overwrite inputs.value for this node's class_type before queueing the job. The title is the contract; the widget is just the default.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/FaraamFide/ComfyUI-ParamNodes.git

Restart ComfyUI, or grab it through ComfyUI Manager by searching "ComfyUI-ParamNodes". No extra dependencies, no model downloads - it's a bare pass-through node. Find it under Params/Input in the Add Node menu.

If you're building a backend service around ComfyUI, this is the node that turns "the CFG was hardcoded in the graph" into "the CFG is a field on your request." That's the whole job, and it does it cleanly.