Subworkflow Modifier Source

Subworkflow Modifier Source (class SWF_SubworkflowModifierSource) is the companion to Subworkflow Modifier, and it lives on the other side of the boundary. The modifier sits inside the inner workflow; this node sits in the outer workflow and hands you the values that need modifying. You use the pair together to do the "expose a model, add LoRAs, pass it back in" trick without tripping ComfyUI's circular reference detection.

Think of the modifier as the port on the inner workflow, and the source as the socket you plug into from outside. The source node reads the same inner workflow file, finds every Subworkflow Modifier boundary in it, and exposes each one's value as an output slot on the outer graph. You grab that value, run it through whatever modification you want, and wire the result back into the modifier's input on the main Subworkflow node. The loop exists conceptually, but because it's split across two node types, ComfyUI never sees a direct cycle.

What you actually set

Just one input:

• workflow - a dropdown of workflow files from ComfyUI/user/default/workflows, exactly like the main Subworkflow node. Pick the same inner workflow it's paired with.

Outputs are dynamic - one per Subworkflow Modifier found in the inner workflow, labeled by each modifier's slot_name. There's no at execution toggle here; the source is always fetched fresh, which is what you want for a debugging/accessory node anyway.

When it's the right tool

Reach for it the moment your inner workflow needs to emit a value, have it changed, and take the changed version back in - LoRA stacking on an inner model being the canonical example. If you never need to feed a modified value back into the inner workflow, you don't need any of this: a plain Subworkflow Output covers one-way export fine.

A few honest caveats. This node only works if the inner workflow actually contains Subworkflow Modifier nodes - if it errors with "No Subworkflow Modifier nodes found," that's the cause, not a bug. The whole modifier/source feature is the newest part of a beta pack with AI-assisted code, so treat slot ordering as arbitrary and expect the occasional rough edge. And the usual installation applies: ComfyUI Manager (search "Subworkflow (reuseable workflows)") or git clone https://github.com/eniewold/ComfyUI-Subworkflow.git into ComfyUI/custom_nodes, restart, hard-refresh the browser. No extra dependencies beyond a recent ComfyUI.