List to String | Ollama Nodes

ListToString takes a list and joins it into a single string with a delimiter - think Python's ", ".join(your_list) rendered as a node. You feed it a LIST, pick a separator, and out comes one STRING. It's a utility node that lives in this pack because the Ollama nodes churn out lists (ListModels' model_list, GenerateOllama's context) and strings are what most other nodes eat.

Why you'd reach for it

The immediate use case in this pack: ListModels gives you a LIST of installed model names, but a lot of downstream nodes - ShowText, prompt templates, anything expecting a plain string - can't handle a list. ListToString turns ["llava:latest", "phi3:latest"] into "llava:latest, phi3:latest" so you can display it or stuff it into a prompt. Same trick works on GenerateOllama's context output if you ever want to peek at what token IDs it's carrying.

Beyond the Ollama nodes, it's a general type adapter. Any node that hands you a list of tags, names, or labels can be flattened into readable text. If you've ever stared at a list output and wished it was a sentence, this is the node.

How it works

It iterates the list, casts each element to a string (so mixed types don't crash it - numbers and text both get flattened), and joins them with your delimiter. Simple, always re-executes, no caching surprises.

Inputs:

• list (required) - the LIST to flatten, forced as an input connection. Must come from another node; you can't hand-type it.
• delimiter (optional) - the separator between elements. Leave it empty for plain concatenation, or set , or | for readable output.

Output:

• string - the joined result, a single STRING ready for any text input.

Installing it

It ships in the slyt/comfyui-ollama-nodes pack, so install the family:

cd ComfyUI/custom_nodes
git clone https://github.com/slyt/comfyui-ollama-nodes
cd comfyui-ollama-nodes
pip install -r requirements.txt

or ComfyUI Manager → search "comfyui-ollama-nodes" → Install → restart. Note the category is LLM/Ollama, not Utility, even though it's a utility at heart - that's where it shows up in the menu.

Gotchas

• Trailing delimiter. The node appends the delimiter after every element, including the last one. With a comma you get "a, b, c," not "a, b, c". Usually harmless, but if you're piping the result into a strict parser, expect a trailing separator and plan around it.
• Class-name collision, dodged. The author wanted to call it StringListToString, but that name is already taken by ComfyUI-Impact-Pack - ComfyUI requires globally unique class names, so it shipped as ListToString. Useful context if you ever see both names in an old workflow and wonder what's what.
• Empty list just yields an empty string, which is fine unless you expected a placeholder. Handle that upstream if it matters.

Honest verdict: it's glue. You won't build a workflow around it, but the moment a list output needs to become readable text, it's the right tool and it costs nothing to have installed.