nano-banana-skill

name	nano-banana-skill
description	Generate and edit images using Google Gemini's Nano Banana image generation API via undyapi.com proxy. Use when users want to generate images from text descriptions, edit existing images with AI, or create visual content. Supports aspect ratio and quality control.

Nano Banana Skill

A Claude Code Skill for AI-powered image generation and editing using Google Gemini's Nano Banana models.

When to Use This Skill

Activate this skill when users request:

• Image generation from text descriptions
• AI image editing or modification
• Creating visual content with specific styles
• Generating images with custom aspect ratios

Trigger phrases:

• "Generate an image of..."
• "Create a picture of..."
• "Edit this image to..."
• "Make an image with..."
• "生成图片"
• "创建图片"
• "编辑图片"
• "AI 绘图"

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Prerequisites

1. API Key: Set environment variable NANO_BANANA_API_KEY

   export NANO_BANANA_API_KEY="your-api-key"
   

2. Required tools: curl, jq, base64

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Available Models

Model	ID	Best For
Flash	gemini-3.1-flash-image-preview	Fast generation, high volume, good quality
Pro	gemini-3-pro-image-preview	Professional quality, complex prompts

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Quick Start

Text to Image Generation

# Basic generation
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "A cute cat wearing a space helmet on Mars" \
  -o ./output

# With aspect ratio
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "A panoramic mountain landscape at sunset" \
  -o ./output \
  -r 16:9

# Using Pro model with 4K output
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "A detailed portrait of a robot philosopher" \
  -o ./output \
  -m pro \
  -s 4K

Image Editing

# Edit an existing image
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "Add a rainbow in the sky" \
  -i ./input/photo.jpg \
  -o ./output

# Style transfer
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "Transform this photo into a watercolor painting" \
  -i ./input/photo.png \
  -o ./output \
  -m pro

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Parameters

Parameter	Short	Description	Default
--prompt	-p	Text description (required)	-
--image	-i	Input image path for editing	-
--output	-o	Output directory	./
--ratio	-r	Aspect ratio (optional)	API default
--size	-s	Output image size (optional)	API default
--model	-m	Model: flash/pro	flash

Aspect Ratios

Flash model (14 ratios): 1:1, 1:4, 1:8, 2:3, 3:2, 3:4, 4:1, 4:3, 4:5, 5:4, 8:1, 9:16, 16:9, 21:9

Pro model (10 ratios): 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9

Output Image Sizes

• 512 - 512px (Flash only)
• 1K - 1024px
• 2K - 2048px
• 4K - 4096px (highest resolution)

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Examples

1. Generate a Logo

bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "A minimalist logo for a coffee shop called 'Bean Dreams', modern flat design, warm colors" \
  -o ./logos \
  -r 1:1 \
  -m pro \
  -s 2K

2. Create Social Media Content

# Instagram post (square)
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "Aesthetic flat lay of coffee and pastries, soft morning light" \
  -o ./social \
  -r 1:1

# Instagram story (portrait)
bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "Motivational quote background, gradient sunset colors" \
  -o ./social \
  -r 9:16

3. Edit Product Photos

bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "Remove the background and add a professional studio backdrop" \
  -i ./product.jpg \
  -o ./edited \
  -m pro

4. Concept Art

bash ~/.claude/skills/nano-banana-skill/scripts/generate.sh \
  -p "Futuristic cyberpunk city street at night, neon lights reflecting on wet pavement, detailed concept art" \
  -o ./concept \
  -r 16:9 \
  -m pro \
  -s 4K

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API Endpoints

• Primary: https://undyapi.com
• Backup 1: https://vip.undyingapi.com
• Backup 2: https://vip.undyingapi.site

For detailed API documentation, see REFERENCE.md.

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Troubleshooting

API Key Not Found

Error: NANO_BANANA_API_KEY environment variable not set

Solution: Export your API key: export NANO_BANANA_API_KEY="your-key"

Rate Limited

Error: 429 Too Many Requests

Solution: Wait a moment and retry, or use the backup endpoints

Invalid Image Format

Error: Unsupported image format

Solution: Supported formats are JPEG, PNG, GIF, WebP

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Best Practices

1. Be specific in prompts: Include style, mood, lighting, and composition details
2. Use Pro model for text rendering: Flash model may not render text accurately
3. Choose appropriate aspect ratios: Flash supports extreme ratios (1:8, 8:1), Pro does not
4. Use 512 for quick iterations: Flash-only, fastest generation

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Output

Generated images are saved to the specified output directory with timestamped filenames:

• nano_banana_20260109_143052.jpg (extension matches actual format from API)

The script also outputs:

• The full path to the generated image
• Any text response from the model (if applicable)