Nano Banana Image Gen

Nano Banana Image Gen

AI-powered image generation using Google Gemini 2.0 Flash.

Use when generating images, thumbnails, banners, or graphics. Supports Japanese text in images.

Triggers: "generate image", "create thumbnail", "make banner", "画像生成", "Nano Banana"

Requirements

• Python 3.10+
• google-genai Python package
• GOOGLE_AI_API_KEY environment variable (Google AI Studio API key)

Instructions

1. Set up API key:

   export GOOGLE_AI_API_KEY=$(grep GOOGLE_AI_API_KEY ~/.openclaw/secrets.env | cut -d= -f2)
   

2. Generate an image:

   python3 {skill_dir}/generate.py \
     --prompt "Description of the image you want" \
     --output "./output.png" \
     --aspect 16:9
   

3. Prompt engineering tips:

   • Be specific: "A futuristic Tokyo skyline at sunset with neon lights" > "Tokyo"
   • Include style: "in watercolor style", "photorealistic", "flat illustration"
   • For text in images: Include exact text in prompt: "Blog banner with text: AIの未来"
   • Specify mood: "warm tones", "minimalist", "vibrant and colorful"

4. Save output to organized directory:

   # Default output location
   --output /mnt/hdd/rey/images/YYYY-MM-DD_description.png
   

Aspect Ratios

Use Cases

• SNS Thumbnails — Eye-catching images for Twitter/note.com posts
• Article Covers — Professional headers for blog posts
• Banners — Promotional graphics
• Presentation Assets — Visual slides for decks

Edge Cases

• API key not set: Error will mention authentication. Check ~/.openclaw/secrets.env.
• Rate limiting: Google AI API has per-minute limits. Wait and retry.
• Japanese text rendering: Works natively but complex layouts may need iteration.
• NSFW content: API will reject inappropriate prompts. Rephrase if blocked.
• Large batch generation: Add delays between requests to avoid rate limits.

Security Considerations

• Never log or display the API key in output.
• Store API key in ~/.openclaw/secrets.env with chmod 600, never in code or git.
• Generated images may contain artifacts — always review before publishing.