Input: Folder (lab)

Input: Folder (lab) is one of those nodes you scroll past a dozen times before it clicks, and then it's in every workflow you build. It's just a folder path you type in - with a validation toggle so the workflow tells you when you've pointed it at nothing. That's the entire job, and it does it well.

You reach for it whenever a workflow needs a directory. Feed it into Image Queue (lab) or File Queue (lab) to say "process everything in here." Use it for a folder of reference images, an output directory, a LoRA dump you're testing. The alternative is a bare STRING widget with a path hand-typed into the node, which is exactly how you end up debugging "why is it loading nothing" for twenty minutes when the answer is a missing s somewhere in the path.

How it works

The node holds two things: a path text field and a check_exists toggle (on by default). When the workflow executes, it runs os.path.isdir() against whatever you typed. If the folder doesn't exist and check_exists is on, you get a clear error - Folder '...' does not exist - instead of a downstream node silently failing on empty input. If the check is off, the path just passes through, which is handy for folders you're about to create.

One thing to internalize: this check runs on the backend, not in your browser. ComfyUI is a server process, so a relative path resolves against wherever you launched ComfyUI from. Absolute paths are the boring, reliable choice - especially if ComfyUI runs on another machine or in a container, where "my desktop folder" doesn't exist.

The inputs that matter

Only two, and you'll set both:

• path - the folder, typed or pasted. Use an absolute path to be safe.
• check_exists - default true. Leave it on while building; you want the early error. Flip it off only if you genuinely need to pass a not-yet-existing folder through.

It outputs a single path (STRING), which you wire into anything that wants a folder - the queue nodes above, a text-based loader, whatever. That's the whole graph: type once, reuse.

Install

There's no per-node install for this - ComfyLab Pack installs as one package of about 35 nodes, all displaying with a "(lab)" suffix. Easiest route is ComfyUI Manager: search for ComfyLab Pack, install, restart.

Manual route:

cd ComfyUI/custom_nodes
git clone https://github.com/bugltd/ComfyLab-Pack.git
cd ComfyLab-Pack
pip install -r requirements.txt

Then restart ComfyUI. The requirements are light (jsonschema, pyyaml, opencv-python, webcolors and a few friends) and there are no model files to download - this is pure workflow tooling, nothing lands in your models/ folder.

Common issues

• "Folder '...' does not exist" - the obvious one. Check the path is right on the machine running ComfyUI, not on your local desktop, and remember it's a folder: a file path fails the isdir check.
• Remote / Docker setups - paths must exist in the server's filesystem. If you're mounting volumes, use the mount point as seen by the container.

It's a dumb little node and proud of it. When your batch workflow starts failing for non-obvious reasons, having the folder existence checked up front is one less thing to wonder about.