Wildcard Prompt Builder 🧩

Not every prompt needs a wildcard file. Sometimes you just want to write a {red|blue|green} {car|bicycle}, {sunny|rainy} day and have ComfyUI pick one option per slot on each run. That's exactly what Wildcard Prompt Builder does - the inline-{}-only companion to the pack's Wildcard Loader, with zero files involved. The whole option set lives right in the node.

This is the tool behind the community's favorite prompt-variety trick: build a template with {brown|blonde|black} hair and {raining|windy|snowing} weather, batch it, and get the same subject across different cameras, lighting and moods without training anything. The KB's prompt-engineering doc calls this the bracket trick - old A1111 syntax that most people who arrived after 2024 never learned. This node is the modern way to run it.

How it works

It's a regex resolver with a seeded random picker. Each {a|b|c} group gets one option chosen via random.Random(seed), groups can nest ({a|{b|c}}), and nested groups resolve innermost-first until none remain. There's a guard loop so pathological templates can't spin forever, and at the end it collapses extra whitespace. Same seed, same output - that's the reproducibility contract, same as its file-based sibling.

The clean thing about keeping it inline: no filesystem, no folder conventions, no file-not-found failure mode. The template is the data. That makes it ideal for sharing workflows - someone opens your graph and sees exactly which options are on the table, no hidden .txt files to hunt down.

Inputs and outputs

Two inputs, that's it:

• template (multiline) - your prompt with {a|b|c} groups. The default is a friendly a {red|blue|green} {car|bicycle}, {sunny|rainy} day so you can test on the first click.
• seed - lock it for reproducibility, randomize it for variety.

One output: prompt, a resolved STRING. Wire it into a CLIP Text Encode (convert that node's text widget to an input first). That's the entire surface area - about as beginner-friendly as this pack gets.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/TensorVizion/OmniNodes

Restart ComfyUI; find Wildcard Prompt Builder 🧩 under TensorVizion/Prompt. No extra dependencies at all - pure Python, no folder_paths, no pip installs.

Where people get burned

• It does not touch wildcard files. Type __color__ in here and it stays literal text - that syntax belongs to Wildcard Loader. If you need file-based tokens, you want the other node. They're siblings, not substitutes, and the README is careful to frame them that way.
• Seed 0 is a fixed seed. Leave the default and you'll see the same combination every run. That trips people constantly - the node isn't randomizing for you; you have to randomize the seed.
• Every run re-picks. There's no "lock this option and only vary that one" widget. For a single locked slot, you'd pull that value out into a separate fixed string and combine them with a prompt combiner.

For quick, self-contained variation - character reference libraries, style tests, seed ladders - this is the node to reach for. It's the simplest thing in the prompt category, and simple is the feature.