ImpactDummyInput

A stand-in. It takes no inputs and produces a single output of the wildcard * type - a nothing-in-particular value you can plug into a socket that needs something connected. It's a debug/scaffolding node, not something you ship in a finished workflow. When you're building a graph and a node refuses to run because an input is dangling, or you're testing a branch in isolation and just need a wire on a pin, this fills the hole.

Impact Pack leans on the wildcard * type all over the place so its nodes can accept arbitrary connections (the pack's own docs note this is a workaround until ComfyUI has proper dynamic types). ImpactDummyInput is the purest expression of that: a value whose only property is "exists and connects to anything."

How it works

There's no computation. It emits a placeholder of type *, which ComfyUI resolves to whatever it's connected to. That's what makes it useful for scaffolding - you can drop it onto an input of almost any type to satisfy the graph's "everything must be connected" requirement while you work on another part. It carries no meaningful data, so it's for structure and testing, not for feeding real values into a computation that depends on them.

The input and output

• No inputs at all.

Output is a single * (wildcard/any). Wire it into whatever needs a placeholder connection. Because it's the any-type, it'll link to sockets of most types without complaint.

How to install it

Part of Impact Pack. ComfyUI Manager: search ComfyUI Impact Pack, Install, restart. Or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Impact-Pack

then pip install -r requirements.txt in ComfyUI's Python environment (portable build: python_embeded\python.exe -m pip ...), restart. Pack's by ltdrdata, who also wrote ComfyUI-Manager - mainstream and safe. This debug node needs nothing extra.

Common issues & troubleshooting

The trap is expecting it to do something. It's a dummy - it carries no real value, so if a downstream node actually needs meaningful data (an image, a real conditioning), a placeholder will either produce nothing useful or error when the node tries to operate on it. Use it to satisfy graph structure while building or testing, then replace it with the real source before you rely on the result. Also, because it's the wildcard * type, ComfyUI's type checking can occasionally grumble even when the connection is fine - that's the pack's known wildcard-typing quirk, not a broken node. If you left one wired into a "finished" workflow and results look empty, that dangling dummy is the first thing to check.