Ⓜ️ Multiplexer Input

The Mithril Multiplexer Input is the node that makes the Mithril Multiplexer work, and it has one job: take any data type, attach a text label to it, and pass the whole bundle along a special MITHRIL_MULTIPLEXER_INPUT wire. Think of it as a shipping label on a box. The box can hold a checkpoint, a conditioning, a string, a latent - anything, because the data input is typed *. The label is what the multiplexer later uses to pick the box.

You almost never use this node alone. You connect its output into one of the Multiplexer's item_1 through item_5 inputs, and then the Multiplexer selects between the labeled items by matching a string against their labels.

The two things you set

• label - string widget, default default_label. This is the string the Multiplexer will match against. Change it, and make it unique: if every input keeps the default, the multiplexer can't tell them apart.
• data - the actual payload, any type. This is where you plug in whatever you want to be able to switch between.

There's a single output, multiplexer_input, which only connects to the Multiplexer's item slots (the type system enforces it). You won't be able to plug it into arbitrary nodes, and that's by design - it's an internal handshake type, not something you route around the graph.

How it works, mechanically

The node wraps the data and label into the node instance itself - get_data() and get_label() are the accessors the Multiplexer calls at runtime. It's a slightly unusual pattern for ComfyUI, where nodes usually return plain values, but it's how the whole labeled-routing scheme stays type-safe-ish. The validation method even shrugs and accepts everything (VALIDATE_INPUTS just returns True - the code comment literally reads "YOLO, anything goes!"), so any type mismatch gets caught downstream at the multiplexer, not here.

The pack's own frontend will even add one of these for you: right-click any item_ slot on the Mithril Multiplexer and pick "Add Multiplexer Input" - it spawns a labeled node and wires it up on the left side of the slot. That's the fastest way to get started, and it beats hunting for the node in the menu.

Gotchas

• Unique labels or nothing works. Two inputs sharing a label means the multiplexer's label map silently collapses them - the last one wins.
• The label is the contract. Change a label and every workflow that selected it by that string breaks. Name them like you mean them.

Install

Part of MithrilNodes - ComfyUI Manager → Install Custom Nodes → search Mithril ("Mithril-Nodes for ComfyUI"), or:

cd ComfyUI/custom_nodes
git clone https://github.com/MithrilMan/ComfyUI-MithrilNodes

Restart after. No requirements, no models, nothing to download. The pack is young (0.1.0) and its README is a placeholder, but the source is small and readable if you ever want to see exactly what the label handshake does.