Nanobanana Image Generation
Generate and edit images using Google Gemini API.
Prerequisites
Requirement Setup
API Key Export GEMINI_API_KEY or add to ~/.nanobanana.env
Dependencies pip install google-genai Pillow python-dotenv
Script ${CLAUDE_PLUGIN_ROOT}/skills/core/nanobanana/nanobanana.py
Basic Usage
Task Command
Generate image python3 nanobanana.py --prompt "description" --output "file.png"
Edit image python3 nanobanana.py --prompt "changes" --input source.png --output "edited.png"
Aspect Ratios
Size Ratio Use Case
1024x1024
1:1 Square, logos
768x1344
9:16 Portrait, stories (default)
1344x768
16:9 Landscape, wallpapers
832x1248
2:3 Portrait photos
1248x832
3:2 Landscape photos
1536x672
21:9 Ultra-wide
Use --size WIDTHxHEIGHT to specify.
Models
Model Trade-off
gemini-3-pro-image-preview
Higher quality (default)
gemini-2.5-flash-image
Faster generation
Use --model MODEL to specify.
Resolution
Resolution Use Case
1K
Testing, drafts (default)
2K
Good quality
4K
Final output, print
Use --resolution RES to specify.
Best Practices
Practice Why
Be descriptive Include style, mood, colors, composition
Use 1:1 for logos Clean square format
Use 9:16 for stories Standard mobile format
Use 16:9 for wallpapers Standard widescreen
Start with 1K Test before using higher resolution
Use flash model for iteration Save time during drafting
Examples
Generate landscape:
python3 nanobanana.py --prompt "Mountain sunset with lake" --size 1344x768 --output "landscape.png"
Generate logo:
python3 nanobanana.py --prompt "Minimalist tech logo" --size 1024x1024 --output "logo.png"
Edit existing image:
python3 nanobanana.py --prompt "Add rainbow to sky" --input photo.png --output "edited.png"
High quality output:
python3 nanobanana.py --prompt "Professional portrait" --resolution 2K --output "portrait.png"
Troubleshooting
Issue Solution
Script fails Check GEMINI_API_KEY is set
No image generated Make prompt more specific
Can't read input Verify file exists and is readable
Can't write output Check directory is writable