first

"Give me the first one." It's the simplest possible question you can ask a list, and first is the node that answers it: one input, one output, the head of the list. It's the counterpart to the pack's last node, and it's so small you could almost skip it - except that in ComfyUI, extracting "the one item I care about" from a batch is a chore you don't want to do by hand.

It's part of Basic data handling, StableLlama's zero-dependency utility pack.

How it works

It indexes the list at position zero and returns that element. There's exactly one behavior worth knowing about, and it's a friendly one: if the list is empty, it returns None instead of erroring. A hard crash on an empty batch would be the worst possible failure mode for a workflow that sometimes produces zero results; this node swallows it gracefully and hands you a None you can branch on.

The input and output

• list (*) - the data list.
• first_element (*) - the first item, or None if the list is empty.

Because the output is a plain single value (not a data list), it plugs into anything that accepts the item's type - which is exactly the point: pull one image out of a batch to preview it, take the first seed from a list, grab the head of a prompt list to test a single run.

Installing it

ComfyUI Manager → search "Basic data handling", or:

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

Restart. No dependencies, no models.

Common issues

• "It returned None and I don't know why." The list was empty. If that's unexpected, trace the source - an upstream filter probably dropped everything. The None is a signal, not a bug.
• "I want a specific position, not the head." Use get item in the same pack and set the index. First is only element zero.
• "I want the last one." That's the pack's last node. Pair them when you need both ends of a batch.