create LIST

Every list in the Basic data handling pack starts somewhere, and usually it starts here. create LIST takes whatever items you give it and bundles them into a single Python list variable - the pack's LIST type - that every other list node (append, length, all, first, and the rest) can chew on. If you've ever stared at a workflow full of "wait, where does this list come from?", this is the answer.

How it works

The inputs are dynamic: you start with one item_0 slot and the node grows more item_N slots as you add them, up to whatever you need. The generic version accepts any type per slot, so it's the only one of the create-family that lets you mix types - item_0 = 42, item_1 = "hello", item_2 = True all ride in the same list.

There's one quirk you'll hit immediately: the trailing empty input slot gets dropped. The UI keeps an empty slot at the end so you have somewhere to type the next item, and the node discards it when it builds the list. The practical upshot: you can't create a list whose last element is an empty string using this node alone. Need a trailing ""? Append it afterwards with the append node. Not a bug, just a design trade-off, and knowing it saves you a confusing five minutes.

The output is a single LIST - one wire, one Python list object.

Where you'd use it

• Seeds, prompts, or filenames for a batch. Build the list, then hand it to something that consumes the whole set.
• A list of booleans to collapse later with all or any.
• The input to extend, sort, slice, min, max - anything that needs a whole collection at once.

If all your items are the same type, you might prefer the typed versions (create LIST from INTs, from FLOATs, from STRINGs, from BOOLEANs) - they coerce each slot to that type automatically, which catches mistakes early.

Installing

It ships in the "Basic data handling" pack by StableLlama. ComfyUI Manager: search "Basic data handling", install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/StableLlama/ComfyUI-basic_data_handling

Restart ComfyUI. The pack has zero dependencies and downloads no models - it's pure Python wrappers, so this is as clean an install as custom nodes get.

Gotchas worth knowing

• The trailing empty slot is dropped - you can't end a created list with an empty string.
• This builds a LIST (single Python list variable). ComfyUI's native data list, where each item gets processed individually, is a different collection type - use the pack's convert to Data List when you need that behavior instead.
• If you just need one number appended to an existing list, append is the lighter tool; reserve create for building from scratch.