nanobanana-skill

name	nanobanana-skill
description	Generate or edit images using Google Gemini API via nanobanana. Triggers: "nanobanana", "generate image", "create image", "edit image", "AI drawing", "图片生成", "AI绘图", "图片编辑", "生成图片".

Nanobanana Image Generation Skill

Generate or edit images using Google Gemini API through the nanobanana tool.

Requirements

1. GEMINI_API_KEY: Must be configured in ~/.nanobanana.env or export GEMINI_API_KEY=<your-api-key>
2. Python3 with depedent packages installed: google-genai, Pillow, python-dotenv. They could be installed via python3 -m pip install -r ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/requirements.txt if not installed yet.
3. Executable: ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py

Instructions

For image generation

1. Ask the user for:

   • What they want to create (the prompt)
   • Desired aspect ratio/size (optional, defaults to 9:16 portrait)
   • Output filename (optional, auto-generates UUID if not specified)
   • Model preference (optional, defaults to gemini-3-pro-image-preview)
   • Resolution (optional, defaults to 1K)

2. Run the nanobanana script with appropriate parameters:

   python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py --prompt "description of image" --output "filename.png"
   

3. Show the user the saved image path when complete

For image editing

1. Ask the user for:

   • Input image file(s) to edit
   • What changes they want (the prompt)
   • Output filename (optional)

2. Run with input images:

   python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py --prompt "editing instructions" --input image1.png image2.png --output "edited.png"
   

Available Options

Aspect Ratios (--size)

• 1024x1024 (1:1) - Square
• 832x1248 (2:3) - Portrait
• 1248x832 (3:2) - Landscape
• 864x1184 (3:4) - Portrait
• 1184x864 (4:3) - Landscape
• 896x1152 (4:5) - Portrait
• 1152x896 (5:4) - Landscape
• 768x1344 (9:16) - Portrait (default)
• 1344x768 (16:9) - Landscape
• 1536x672 (21:9) - Ultra-wide

Models (--model)

• gemini-3-pro-image-preview (default) - Higher quality
• gemini-2.5-flash-image - Faster generation

Resolution (--resolution)

• 1K (default)
• 2K
• 4K

Examples

Generate a simple image

python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py --prompt "A serene mountain landscape at sunset with a lake"

Generate with specific size and output

python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py \
  --prompt "Modern minimalist logo for a tech startup" \
  --size 1024x1024 \
  --output "logo.png"

Generate landscape image with high resolution

python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py \
  --prompt "Futuristic cityscape with flying cars" \
  --size 1344x768 \
  --resolution 2K \
  --output "cityscape.png"

Edit existing images

python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py \
  --prompt "Add a rainbow in the sky" \
  --input photo.png \
  --output "photo-with-rainbow.png"

Use faster model

python3 ${CLAUDE_PLUGIN_ROOT}/skills/nanobanana-skill/nanobanana.py \
  --prompt "Quick sketch of a cat" \
  --model gemini-2.5-flash-image \
  --output "cat-sketch.png"

Error Handling

If the script fails:

• Check that GEMINI_API_KEY is exported or set in ~/.nanobanana.env
• Verify input image files exist and are readable
• Ensure the output directory is writable
• If no image is generated, try making the prompt more specific about wanting an image

Best Practices

1. Be descriptive in prompts - include style, mood, colors, composition
2. For logos/graphics, use square aspect ratio (1024x1024)
3. For social media posts, use 9:16 for stories or 1:1 for posts
4. For wallpapers, use 16:9 or 21:9
5. Start with 1K resolution for testing, upgrade to 2K/4K for final output
6. Use gemini-3-pro-image-preview for best quality, gemini-2.5-flash-image for speed