| name | Nanobanana Image Generation |
| description | Generate and edit images using nanobanana CLI with Google Gemini API. Use for creating images, slides, banners, and visual content from text prompts. |
| dependencies | nanobanana (brew tap skorfmann/nanobanana && brew install nanobanana) |
Nanobanana Image Generation Skill
Generate images using Google's Gemini API via the nanobanana CLI tool.
Prerequisites
-
Install nanobanana:
brew tap skorfmann/nanobanana
brew install nanobanana
-
Set your Gemini API key:
export GEMINI_API_KEY="your-api-key"
Get a key at: https://aistudio.google.com/apikey
When to Use This Skill
Use this skill when the user asks to:
- Generate images from text descriptions
- Create presentation slides
- Design banners, thumbnails, or social media images
- Edit or transform existing images
- Combine multiple images
- Create consistent branded visuals using templates
Basic Commands
Text-to-Image Generation
nanobanana "your prompt here"
nanobanana -o output.jpg "your prompt here"
nanobanana -aspect 16:9 -size 2K -o slide.jpg "your prompt here"
Image Editing (with input image)
nanobanana -i input.jpg "transform into watercolor style"
nanobanana -i photo.jpg "add sunglasses to the person"
Multi-Image Composition
nanobanana -i background.jpg -i subject.jpg "place the subject in the scene"
nanobanana -i template.jpg -i content.jpg "apply the template style"
Options
| Flag | Description | Default |
|---|
-i <file> | Input image (repeatable) | none |
-o <file> | Output filename | auto-generated |
-model <name> | Model: lite, flash, pro, or full model ID | flash |
-aspect <ratio> | Aspect ratio | 1:1 |
-size <size> | Image size (0.5K, 1K, 2K, 4K; model-dependent) | 1K |
-version | Show version | - |
Models
lite (Nano Banana 2 Lite): fastest/cheapest, drafts and high volume; 1K onlyflash (Nano Banana 2): default go-to model; 0.5K-4K, all aspect ratiospro (Nano Banana Pro): highest quality for complex/detailed work; 1K/2K/4K
Supported Aspect Ratios
All models: 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9
flash only: 1:4, 4:1, 1:8, 8:1 (extreme banners)
Workflow Patterns
Single Image
nanobanana -o hero.jpg "a futuristic cityscape at sunset, cyberpunk style"
Presentation Slides (Consistent Style)
nanobanana -aspect 16:9 -size 2K -o template.jpg \
"presentation slide template with dark blue gradient, modern minimal style"
nanobanana -i template.jpg -aspect 16:9 -size 2K -o slide_01.jpg \
"using this template style, create a title slide for 'Project Alpha'"
nanobanana -i template.jpg -aspect 16:9 -size 2K -o slide_02.jpg \
"using this template style, create a slide showing three key features"
Image Editing Workflow
nanobanana -o draft.jpg "a logo for a tech startup"
nanobanana -i draft.jpg -o final.jpg "make the colors more vibrant and add a subtle glow effect"
Prompting Tips
- Be specific: Include style, mood, colors, composition details
- For edits: Reference "this image" or "keep everything else identical"
- For consistency: Use a template image with
-i flag
- For slides: Always use
-aspect 16:9 -size 2K
Pricing (approximate, per image)
lite: ~$0.034 (1K)flash: ~$0.045 (0.5K), ~$0.067 (1K), ~$0.101 (2K), ~$0.151 (4K)pro: ~$0.134 (1K/2K), ~$0.24 (4K)
Example Prompts
Marketing Banner
nanobanana -aspect 16:9 -size 2K -o banner.jpg \
"professional marketing banner for a SaaS product launch,
dark gradient background, glowing tech elements,
modern minimal design, no text"
App Icon
nanobanana -aspect 1:1 -size 1K -o icon.jpg \
"app icon for a meditation app,
soft purple gradient, lotus flower symbol,
simple flat design, rounded corners style"
Social Media Post
nanobanana -aspect 1:1 -size 2K -o social.jpg \
"instagram post announcing a new feature,
bright cheerful colors, confetti elements,
celebratory mood, tech startup aesthetic"
Troubleshooting
- No GEMINI_API_KEY: Set the environment variable
- Wrong file extension: nanobanana auto-corrects to match actual format (usually .jpg)
- Image too large: Use smaller
-size option (1K instead of 4K)
More Information
