FL Path Type Checker

A small classification node for a specific pain point: when a path string is being built or passed around dynamically inside a graph - assembled from parts, coming from an upstream node, pulled from a config - you sometimes don't actually know what kind of path you've got until something downstream fails on it. FL_PathTypeChecker looks at a path string and tells you what shape it's in: absolute, relative, a Windows UNC network path, something URL-like, or tied to a specific drive letter.

How it works

It's pure string analysis - no filesystem access, no checking whether the path actually exists, just pattern-based classification of the string's format. That distinction matters: this node answers "what kind of path is this" (so you can decide how to handle it), not "does this path point to something real." For that second question you'd still need an existence check elsewhere in your graph. This is the kind of node you reach for when a workflow accepts paths from multiple different sources - user input, a directory-crawl node, a config file - and you want to branch behavior depending on which format showed up, rather than assuming everyone hands you the same kind of path string.

The inputs and outputs that matter

• input_path - the only input, a raw path string.
• Output: PATH - a Fill-Nodes-specific type carrying the classification result. Since it's a custom type rather than a plain STRING, it's meant to connect onward to other nodes in this pack built to consume it, not to arbitrary path-string inputs elsewhere in ComfyUI - check what a given downstream node actually expects before assuming this output will slot straight in.

That's the entire node - no configuration knobs, just classify-and-output.

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. Pure string parsing, no dependency beyond the standard library. Fill-Nodes overall is a large, general-purpose collection from filliptm, one prolific solo author, spanning image FX, PDF tools, GPT/Gemini/Fal API wrappers, and an entire KSampler family - this is one of the smallest, most self-contained utilities in it.

Common issues & troubleshooting

Output won't connect where you expected. PATH is a pack-specific type, not ComfyUI's generic STRING - if you're trying to wire it into a node that expects a plain string (like most path-input fields elsewhere), that connection may simply not be offered. Check whether the node you're targeting actually accepts PATH.

Classification looks wrong for an edge-case path. Since this is pattern-based string analysis rather than filesystem-aware resolution, unusual formats (a path with mixed slash styles, an environment-variable placeholder that hasn't been expanded yet) can classify differently than you'd expect from just eyeballing it. If you need the classification to be reliable, pre-normalize the string (consistent slashes, expanded variables) before it reaches this node.

You actually wanted to know if the path exists, not what type it is. This node doesn't touch the filesystem at all - it's answering a different question. Pair it with an existence-check step if that's what you actually need.