🤖 Leon String Combine

In a pack that's mostly "send money to a cloud API," this node does the opposite: no network, no key, no cost - just two strings and a gluestick. Leon_String_Combine_Node takes string_1, string_2, and a linking_element, and returns string_1 + linking_element + string_2 as a single combined_string output. That's the entire job. It's a plain utility node, the ComfyUI equivalent of a + operator, and it's here because the author clearly kept hitting the same need while wiring up their own workflows.

Why would you reach for it? Because ComfyUI workflows get string-shaped fast, and one of the most common patterns is assembling a prompt or a path from parts. It sits naturally before an API generation node in this same pack: a Leon_String_Combine_Node concatenating a base prompt with a dynamic subject, feeding its combined_string into the prompt input of, say, Leon_Nano_Banana_API_Node. Or building a file path to feed a save node. Or gluing a filename prefix to a batch counter. The linking_element is the sneaky MVP - leave it empty for plain concatenation, set it to ", " for comma-joined prompt fragments, or "/" when you're assembling paths.

The inputs

All three are plain STRING fields, and they're all required by the schema:

• string_1 - the left part.
• linking_element - what goes between (can be empty, or ", ", " ", "-", "/"…).
• string_2 - the right part.

One combined_string output, which wires into any STRING input downstream.

Installing

Same pack as everything else here - ComfyUI Manager (search Leon) or:

cd ComfyUI/custom_nodes/
git clone https://github.com/l3ony2k/comfyui-leon-nodes comfyui-leon-nodes
pip install -r requirements.txt

Restart, done. No key, no models, no nothing - this node runs entirely in Python with zero dependencies beyond what ComfyUI already ships.

Notes

There's not much to troubleshoot on a concatenation node. The one thing to remember is the type discipline: the inputs are STRING, so if you're feeding a number from a counter node, you'll need a node that converts to string first (or use ComfyUI's built-in text utilities). And note it only joins two strings - if you're chaining three or four fragments, you'll stack two of these nodes. It's unglamorous, but it's free and local, and in a pack full of metered API calls that's quietly its best feature.