None Primitive

None Primitive is the shortest pitch in this pack: it has no inputs and one output, NONE, which is - you guessed it - an explicit None. That sounds useless until you realize that ComfyUI's optional inputs treat "not connected" and "explicitly None" as the same thing, and sometimes you need to make something None on purpose.

The pattern it exists for is the null-output placeholder, straight out of the plumbing playbook. In a workflow with a fallback switch (the kind that walks its inputs and passes the first non-null one - rgthree's Any Switch is the canonical example), you can mute a branch from inside the data by wiring a None into the optional input it feeds. The branch looks connected on the canvas, but at runtime it contributes nothing, and the fallback logic downstream skips it cleanly. You get the same effect as bypassing a node, but you control it with a wire instead of a right-click - which means you can toggle it from another node, or gate it with Is None from this pack.

The two nodes are a pair: None Primitive makes the explicit None, Is None detects one (or a missing connection). Wire None Primitive into Is None and you can prove to yourself exactly how "connected but None" behaves in your graph - a decent way to debug the optional-input convention before you build a whole conditional workflow on top of it.

The honest limits

Because the output type is the * wildcard, you can plug it into just about any optional input. But don't expect it to do anything subtle: it's a static None, not a switch, not a toggle. If you want "sometimes a value, sometimes nothing, depending on a condition," that's a job for a switch node wired to a real source - this node just provides the "nothing" half of that equation.

One thing to know if you're new to the convention: on a lot of optional inputs, an unconnected wire and a wired-in None are genuinely equivalent, so this node's value is mostly about explicitness and about making the flow readable - "here's the branch that's deliberately empty." It's a legibility and controllability tool, and it does its one job without any moving parts.

Install

Ships in comfyui-sg-nodes by sebagallo. ComfyUI Manager → search comfyui-sg-nodes, or:

cd ComfyUI/custom_nodes
git clone https://github.com/sebagallo/comfyui-sg-nodes

Restart ComfyUI; it's under SGNodes/Utilities. No models, no extra dependencies.