Nano Banana Pro Image Generator
Generate images using Google's advanced Nano Banana Pro model (gemini-3-pro-image-preview).
Prerequisites
The user must have GEMINI_API_KEY environment variable set with a valid Google AI API key.
Usage
The script is located in the same directory as this SKILL.md file. Run it with uv run:
uv run /path/to/skills/nano-banana-pro/generate_image.py "your prompt" -o output.pngWhen this skill is invoked, locate generate_image.py in the skill directory and run it.
Parameters
| Parameter | Required | Description |
|---|---|---|
prompt | Yes | Text description of the image to generate or transformation to apply |
-o, --output | Yes | Output filename (you decide the path based on context) |
-i, --image | No | Input image(s) for editing/transformation or as context/reference (can be used multiple times) |
--aspect-ratio | No | One of: 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9 (default: 1:1) |
--size | No | Image size: 1K, 2K, 4K (default: 1K) |
Examples
Basic image generation:
uv run generate_image.py "A sunset over mountains" -o sunset.pngInfographic with specific aspect ratio:
uv run generate_image.py "Infographic showing the water cycle with labeled stages" -o water_cycle.png --aspect-ratio 9:16High-resolution ultrawide:
uv run generate_image.py "Professional photo of a modern office space" -o office.png --aspect-ratio 21:9 --size 4KEdit an existing image:
uv run generate_image.py "Add a sunset sky to this image" -i photo.png -o edited.pngTransform with style:
uv run generate_image.py "Make this look like a watercolor painting" -i input.jpg -o watercolor.pngCombine multiple images:
uv run generate_image.py "Create a collage blending these images together" -i img1.png -i img2.png -o collage.pngUse image as context/reference:
uv run generate_image.py "Generate a new landscape in the same style as this reference" -i reference.png -o new_landscape.pngModel Capabilities
Nano Banana Pro excels at:
- Accurate infographics with real data (uses Google Search grounding)
- Text rendering in images
- Image editing and transformation from input images
- Context-aware generation using reference images for style, composition, or subject
- Cartographic visualizations and maps
- Detailed instruction following
- Chain-of-thought reasoning for complex visual tasks
Output
The script prints:
- Progress message while generating
- Path to saved image on success
- Any text response from the model
- Error message if no image was generated