Prompt Studio Suite
Reference-image prompt engineering workflow for still images and MiniMax H3 video, with built-in aspect-ratio detection.
ComfyUI Prompt Studio Suite v3.3
Turn a reference image and a simple idea into a production-ready image prompt or MiniMax H3 video script — directly inside ComfyUI.
Prompt Studio sends the reference image to multimodal models through OpenRouter and combines that visual context with your creative direction. A small built-in helper node also reports the reference image's closest standard aspect ratio so you can match that ratio in the image or video generator you use afterward.
What's new in v3.3
AspectRatioDetectoris now included directly with Prompt Studio.- No separate mystery aspect-ratio node pack is required.
- Aspect ratio is a user-facing readout only; it is not injected into Still or Video prompt context.
- The detector is intentionally simple:
IMAGE -> aspect_ratio_str. - Public workflow ships with the OpenRouter API-key field blank.
Features
- Reference-aware prompting: Uses the supplied reference image as multimodal visual context.
- Aspect Ratio Readout: Reports friendly ratios such as
2:3 (Classic Portrait),3:2 (Classic Landscape),16:9 (Landscape), and9:16 (Portrait / Story). - Dual Engine Architecture:
- Track A — Still Prompt Studio: Leave Still Direction blank for faithful reconstruction guidance, or add creative direction to modify the scene.
- Track B — MiniMax H3 Video Script: Produces a structured video prompt with shots, timing, camera direction, soundscape, and music cues.
- Independent directions: Still and Video directions can be controlled separately.
- Switchboard Control: Run either track independently.
- Target Model: Tailor the still prompt-writing style for Generic, FLUX, Krea 2, or SDXL.
Required Custom Nodes
Install these through ComfyUI Manager:
| Node Pack | Required Nodes |
|---|---|
| ComfyUI-Custom-Scripts | ShowText|pysssss |
| ComfyUI-KJNodes | StringConstant |
| rgthree-comfy | Fast Bypasser (rgthree) |
| comfyui-openrouter | OpenRouterNode |
AspectRatioDetector is included with Prompt Studio itself.
OpenRouter usage requires an OpenRouter account and may incur API charges depending on the model selected.
Installation
ComfyUI Manager / Registry
Once Prompt Studio is published to the Comfy Registry, install Prompt Studio Suite from ComfyUI Manager and restart ComfyUI.
Manual
Clone or download this repository into:
ComfyUI/custom_nodes/ComfyUI-Prompt-Studio
Restart ComfyUI afterward.
If you previously installed the old standalone ComfyUI_AspectRatioDetector test/local folder, remove it from custom_nodes to avoid registering the same legacy node twice.
Quick Start
- Install the required node packs above and restart ComfyUI.
- Open
prompt_studio_v3.json. - Enter your OpenRouter API key in OpenRouter API Key.
- Load a reference image.
- Confirm Detected Aspect Ratio reports the reference shape.
- Optionally enter Still Direction and/or Video Direction.
- Select the track(s) you want and queue the workflow.
- Use the resulting prompt/script in your target image or video generator, matching its output aspect ratio to the displayed reference ratio when desired.
Aspect Ratio Detection
Prompt Studio's built-in detector intentionally does one job: it maps the reference image dimensions to the closest common aspect ratio and displays that ratio.
It does not:
- resize the image,
- choose a generation resolution,
- inject aspect-ratio instructions into the AI prompt,
- or control an external image/video generator.
This keeps the readout deterministic while leaving generation settings under your control.
API Key Safety
Never publish or share a workflow after entering your personal OpenRouter API key without removing the key first. The repository's public workflow is distributed with this field blank.
Outputs
- Still track: production-ready still-image prompt.
- Video track: MiniMax H3-oriented production script.
- Detected Aspect Ratio: friendly reference ratio for matching downstream generation.
License
See LICENSE.