Base Model Parameters SD3API JK🐉

Stability's SD3 era was a strange one for local users: the model was awkward to run locally, so people leaned on Stability's API, and JakeUpgrade built a whole API workflow around it around late 2024. Base Model Parameters SD3API JK is the parameter node from that era - it holds your prompts, picks an aspect ratio, and hands you the resolved width and height. It's marked deprecated now, and honestly the SD3 moment has passed, but old workflows still reference it, so it's worth a two-minute introduction.

How it works

You give it a positive and negative prompt, a boolean use_input_prompt, and an aspect_ratio from the dropdown: 1:1, 5:4, 3:2, 16:9, 21:9, 4:5, 2:3, 9:16, 9:21.

The use_input_prompt toggle is the interesting part. When off, the node uses the positive/negative text typed into its own fields. When on, it overrides those with whatever is wired into the optional input_positive / input_negative inputs - so an upstream prompt-generation node (a VLM, a prompt template, an API response) can feed the prompts in, and the API call uses those instead of hardcoded defaults.

The aspect ratio resolves to pixel dimensions through SD3's standard table - 1:1 → 1024×1024, 16:9 → 1344×768, 21:9 → 1536×640, and so on. Those WIDTH/HEIGHT integers are what the API payload needs.

Inputs and outputs

• positive, negative - the prompts.
• use_input_prompt - switch to the wired-in prompt inputs.
• aspect_ratio - the ratio dropdown.
• input_positive, input_negative - optional overrides, used when use_input_prompt is on.
• POSITIVE, NEGATIVE (strings), ASPECT_RATIO (string), WIDTH, HEIGHT (integers).

Installing it

Ships in ComfyUI-JakeUpgrade:

• ComfyUI Manager → search "JakeUpgrade" → install → restart.
• Or:

cd ComfyUI/custom_nodes
git clone https://github.com/jakechai/ComfyUI-JakeUpgrade
cd ComfyUI-JakeUpgrade
pip install -r requirements.txt

Windows portable: run install.bat or ../../../python_embeded/python.exe -s -m pip install -r requirements.txt.

It's flagged deprecated in the source. If it's missing from your node list, the pack's README explains the config.ini LOAD_DEPRECATED_NODES setting - but unless you're resurrecting an SD3 API workflow, you don't need to bother.

Common issues

• Your wired-in prompts are ignored. If use_input_prompt is off, input_positive/input_negative do nothing. Flip the toggle.
• It's for the SD3 API, not local SD3. The outputs are strings and integers for an API payload, not tensors. Don't expect it to feed a local sampler directly.
• The aspect ratio table is SD3-specific. Those dimensions came from SD3's resolution scheme. Feeding them to a different model's API may not be ideal - the values are just numbers, and other models have their own preferred resolutions.

This is a fossil from a specific October 2024 moment, marked deprecated for good reason. If you meet it in a downloaded workflow, know what it does and why it exists - and then decide whether your project actually needs it or just needs the WIDTH/HEIGHT numbers extracted.