tomevault-io Nano Banana Image Generator
Generate images using Google's Gemini 2.5 Flash Image model (codename: Nano Banana).
State Dependencies
| Source | Location | Read | Write | Description |
|---|---|---|---|---|
| Generate Script | ~/.claude/skills/nano-banana-image-generator/scripts/generate.sh |
✓ | Main generation script | |
| Thumbnail Script | ~/.claude/skills/nano-banana-image-generator/scripts/generate_thumbnail.py |
✓ | 16:9 thumbnail generator | |
| Image Script | ~/.claude/skills/nano-banana-image-generator/scripts/generate_image.py |
✓ | Python with aspect ratio control | |
| Best Practices | ~/.claude/skills/nano-banana-image-generator/best_practices.md |
✓ | Prompt engineering guidelines | |
| API Key | $GOOGLE_API_KEY or $GEMINI_API_KEY |
✓ | Required for API access | |
| Output Directory | $OUTPUT_DIR or current directory |
✓ | Where images are saved | |
| Generated Image | User-specified path | ✓ | Output PNG file |
Quick Start
Generate a simple image:
bash ~/.claude/skills/nano-banana-image-generator/scripts/generate.sh "A red apple on white background" apple.png
Generate a 16:9 thumbnail:
python3 ~/.claude/skills/nano-banana-image-generator/scripts/generate_thumbnail.py "YouTube thumbnail showing AI agents" /tmp/thumb.png
Generate with custom output directory:
OUTPUT_DIR=/tmp bash ~/.claude/skills/nano-banana-image-generator/scripts/generate.sh "Sunset over mountains" sunset.png
Scripts
| Script | Purpose | Output |
|---|---|---|
scripts/generate.sh |
General image generation | 1024x1024 PNG |
scripts/generate_thumbnail.py |
16:9 thumbnails | 1344x768 PNG |
scripts/generate_image.py |
Python with aspect ratio control | Configurable |
Pricing & Limits
- Cost: $0.039 per image
- Free tier: 500 requests/day
- Generation time: ~22 seconds
- Resolution: 1024x1024 (square), 1344x768 (16:9)
Best Practices
For detailed prompt engineering and brand styling guidelines, see best_practices.md.
Critical Constraints
| Element | Maximum |
|---|---|
| Visual boxes/shapes | 10 maximum |
| Text pieces/labels | 10 maximum |
| Hierarchy levels | 3 maximum |
Prompt Structure
DO: Write narrative descriptions
Create a simple infographic with black background showing a central concept
with 4-5 supporting elements. Use white text, DM Sans font, bold titles.
DON'T: Use keyword lists
LinkedIn post, gradient, red, white, large text, 15 boxes, arrows everywhere
Brand Styling (Eugene's)
Include in prompts for brand consistency:
Use Eugene's brand style: black background (#000000), white text (#ffffff),
DM Sans font, bold 700 weight for titles, clean minimal design.
Use Cases
Perfect For:
- Social media infographics and carousels
- YouTube thumbnails
- Diagrams and technical documentation
- Product mockups
- Mobile-optimized content
Not Ideal For:
- Hyper-realistic photography
- Complex multi-font typography
- Fine detail technical renders
Environment Variables
GOOGLE_API_KEYorGEMINI_API_KEY- API key (required)OUTPUT_DIR- Output directory (default: current directory)
Examples
Infographic:
bash scripts/generate.sh "Simple framework diagram with black background. CENTER: 'AI Agents' in large white text. SURROUNDING: 4 icons for Planning, Memory, Tools, Learning. DM Sans font, minimal design." agents_framework.png
Thumbnail:
python3 scripts/generate_thumbnail.py "Professional YouTube thumbnail: bold white text 'DEEP AGENTS' on dramatic black background with subtle blue glow, tech aesthetic" deep_agents_thumb.png
Completion Checklist
- API key verified (GOOGLE_API_KEY or GEMINI_API_KEY)
- Prompt crafted following best practices (narrative description, not keyword lists)
- Critical constraints respected (max 10 boxes, max 10 text pieces, max 3 hierarchy levels)
- Appropriate script selected (generate.sh, generate_thumbnail.py, or generate_image.py)
- Output directory confirmed or created
- Image generated successfully (~22 seconds)
- Output file path provided to user
- Cost noted ($0.039 per image)
Source: Abilityai/cornelius — distributed by TomeVault.