FL Node Loader

This is about as minimal as a ComfyUI node gets: it takes a TRIGGER input and returns a TRIGGER output, and does nothing to the data passing through. That sounds pointless until you've hit the actual problem it solves - ComfyUI's graph executes based on data dependencies, and sometimes you need node B to run strictly after node A even though B doesn't actually need any data from A. FL_NodeLoader is a plain, deterministic dependency link for exactly that case, as opposed to its sibling FL_NodePackLoader, which is a similar pass-through but deliberately set to always re-run (via IS_CHANGED = NaN) - the two solve related but different problems, and it's worth not confusing them.

Why this exists

ComfyUI doesn't have an explicit "run after" primitive in the base graph - ordering is implicit, inferred from what data flows into what. If you have a node that has side effects (writes a file, triggers something external) and you need a different node to only fire once that's done, but the second node doesn't consume any of the first one's actual output data, you're stuck - unless you wire a dummy connection between them. That's the whole reason TRIGGER exists as a type in this pack: it's a value with no real content, whose entire purpose is to force a dependency edge in the graph.

The inputs and outputs that matter

• trigger (TRIGGER) in, TRIGGER out. There is nothing else - no configuration, no widgets to set.

Both the input and output are the pack-specific TRIGGER type, which means this node only makes sense wired between other nodes in your graph that produce or consume TRIGGER values - it's connective tissue, not something you'd drop in standalone.

How to install it

Via ComfyUI Manager: search "ComfyUI_Fill-Nodes" and install, or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/filliptm/ComfyUI_Fill-Nodes

then restart ComfyUI. Nothing to configure and no dependency beyond the base pack. Fill-Nodes overall is a large, general-purpose collection from one prolific solo author, filliptm, covering image FX, PDF tools, GPT/Gemini/Fal API wrappers, and much more - this loader node is one of the smallest, simplest things in it.

Common issues & troubleshooting

Why isn't my downstream node re-running when I expect it to? FL_NodeLoader is a normal, cached pass-through - if its input hasn't changed, ComfyUI won't re-execute it or anything chained after it. If you actually want to force re-execution every run regardless of cache state, that's what the sibling FL_NodePackLoader is for (its NaN change-detection trick), not this node.

Nothing seems to connect to it. That's expected if you don't have a TRIGGER-producing node upstream - this type is specific to this pack's ordering pattern, not a general ComfyUI concept, so it won't show up as a valid connection target for ordinary IMAGE/LATENT/MODEL outputs.

You're not sure you even need this node. If your actual dependency is expressible through real data - e.g., node B genuinely needs node A's output image - just wire that directly and skip TRIGGER entirely. This node earns its place specifically when there's no real data dependency but you still need an ordering guarantee.