Join String

Join String does exactly one thing: it takes a list of strings and glues them together with a delimiter between them. Feed it ["a cat", "sitting", "on a mat"] with delimiter ", " and you get "a cat, sitting, on a mat". That's the whole node - two inputs, one output - and it's the kind of thing you don't think about until you need it, then you need it constantly.

Inputs and output

• string_list - the list of strings to join.
• delimiter - the separator, default ", ". Set it to "" for no separator, "\n" for newlines between items.

Output is a single STRING. Two details worth knowing: it converts every element to a string via str(), so you can throw non-string items at it without an instant crash, and ComfyUI lists (like the outputs of Regex Find All or Regex Split String) plug straight in.

Why this one instead of a dozen others

There are a million join-string nodes out there; this one ships inside the SeanScripts pack, which means it's already installed when you use the pack's vision models - no extra custom-node scavenger hunt. ComfyUI core has grown equivalent primitives, but if you've already got this pack for captioning, this node costs you nothing and works identically. It also pairs naturally with the pack's captioning output: caption a list of images, join the results, and you've got one combined text block to save or feed onward.

Install

It comes with the SeanScripts pack - no separate install. ComfyUI Manager search ComfyUI-PixtralLlamaVision, or:

cd ComfyUI/custom_nodes
git clone https://github.com/SeanScripts/ComfyUI-PixtralLlamaMolmoVision

Then restart ComfyUI. No dependencies beyond the pack's standard ones.

Troubleshooting

• Output looks jammed together - your delimiter is empty or the wrong character. Check the delimiter input.
• Wrong item type errors - rare, since it stringifies everything, but a deeply nested non-string may still trip it up.
• It's not joining because the input isn't a list - if you pass a single string instead of a list of strings, you'll get back the string unchanged. Make sure the upstream node is actually outputting a list.

Boring, tiny, and exactly what it says on the tin. Sometimes that's the best kind of node.