Ino String Replace Placeholder

If you've ever written "A {subject} in {style} style" and wished ComfyUI would just fill in the braces for you, this is that node. Ino String Replace Placeholder takes a string, finds every {placeholder} token in it, and swaps them all for a value you provide. It's the pack's template-filling node, and it's how you turn a prompt skeleton into an actual prompt without hand-editing text between runs.

It belongs to the ComfyUI Ino Nodes pack. Two string inputs in, one string out - the smallest possible surface.

The inputs

• input_string - the template, e.g. "Test {String}" (the default).
• replace_string - the value that fills the token(s), default "Replaced".

Under the hood it runs a regex matching anything of the shape {...} and replaces every match with replace_string. So "a {x} and {y}" with replace_string = "thing" becomes "a thing and thing". The brace content doesn't matter - it could be {prompt}, {SEED}, or {anything-at-all} - they all get the same value.

That's the key thing to understand, because it's both the feature and the limit. If your template has exactly one token, this is perfect: wire a wildcard, a filename, or a user input into replace_string and the template becomes a live form. But a single node can't fill {prompt} and {style} with different values - they'd both become the same string. For that, you'd either chain two of these (fill {prompt} first, then {style}) or reach for a dedicated prompt-builder.

Output and wiring

The single string output feeds the finished text anywhere a string goes: CLIP Text Encode, Ino Save Text, a filename prefix. A common pattern is keeping the template in a text node, feeding the variable in from a seed or a LoRA name, and sending the result to the encoder - so changing the variable changes the prompt without touching the template.

Install

It ships with the pack:

# ComfyUI Manager: search "ComfyUI Ino Nodes", install, restart
# or manually:
cd ComfyUI/custom_nodes
git clone https://github.com/nobandegani/ComfyUI-InoNodes.git
cd ComfyUI-InoNodes
pip install -r requirements.txt

Restart ComfyUI after. Nothing heavy here - no models, and requirements.txt pulls in the pack's one real dependency, inopyutils. The pack needs a current ComfyUI (V3 schema, v0.18.1+), and the README's manual-install path cd comfyui_ino_nodes is a typo; the folder is ComfyUI-InoNodes.

If you paste a string in and nothing changes, check that your token is actually wrapped in {} - the regex matches braces and only braces. Bare token without braces is a job for Ino String Replace, the literal-substring sibling in the same pack.