Symbiotica Template Prompt

This is the glue step in Symbiotica's template pipeline, and it's the rare node in the pack that does one tiny thing well. You've built a template sheet - either with the Template Builder or the Template Editor - and you've got a SYMBIOTICA_TEMPLATE bundle in hand. Now you need to actually ask an image model to fill those regions in. Symbiotica Template Prompt reads the bundle's regions and writes the numbered, per-region edit prompt that the Nano Banana edit nodes (or any img2img editor) can follow.

No API, no key, no model. It's a string formatter with opinions, and that's exactly right - hand-writing these prompts is tedious, and getting them consistent matters when you're doing ten sheets a month.

How it works

It assembles a prompt from three parts, in order:

1. Your optional scene instruction, prepended if you typed one (overall scene/style direction).
2. A fixed framing line - the sheet is a sprite template, replace each listed region's content with a new game asset, keep position and size, leave everything outside the regions untouched.
3. One numbered line per region, sorted by z-index, each naming the region, its asset type in parens, and its client description - falling back to "match the sheet style" where a region has no description.

So you get something like:

The image is a sprite template sheet. Replace the content of each
listed region with a new game asset, keeping position and size; keep
everything outside the regions unchanged.
1. "Serving" (food): a plated pasta dish, warm tones...
2. "Ready" (food): ...

That's the whole trick: the regions carry their own client briefs inside the bundle, and this node knows how to read them.

Inputs

• template - the SYMBIOTICA_TEMPLATE wire, straight from the Builder or Editor. Required.
• scene - optional, multiline. An overall scene/style instruction prepended to the region list. If your whole sheet has a shared look, put it here instead of repeating it per region.

Output

• prompt - a single STRING, the assembled edit prompt.

Wire it where? The pack's own Wavespeed Nano Banana 2 Edit node is the natural target, or the Regional Edit node, or any LLM step that refines before the image call. If you're using the Editor's sheets/sheet_prompts outputs, note those already carry per-sheet prompts - this node is the alternative path that works off a single bundle rather than ticked sheets.

Install

One node of the Symbiotica pack:

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

Restart ComfyUI, or ComfyUI Manager → search Symbiotica → install. No models download, no dependencies beyond Pillow.

Common issues

Honestly, this node has few failure modes - the main one is upstream. If template is an empty or stale bundle (say, a Builder run that raised on "no assets with reference files"), the prompt comes out with no region lines and the fixed framing line alone, which reads fine but does nothing useful. Re-run the Builder or Editor that produced the bundle, then re-run this. And if your LLM or edit node seems to ignore the region list, check that the image you're sending is the same sheet the bundle describes - mixing a Builder sheet with an Editor bundle is the classic mix-up.