Nano Banana - Image Generation API Skill

Nano Banana - Image Generation API

Generate images from text prompts using Google Nano Banana (Gemini's native image generation).

Base URL

https://api.eng0.ai/api/data

Models

| Model | ID | Best For | Max Resolution | |-------|-----|----------|----------------| | Flash | flash | Fast generation, high-volume tasks | 1024px | | Pro | pro | Professional quality, complex prompts | 4K |

Generate Image

Create an image from a text description.

curl -X POST https://api.eng0.ai/api/data/images/generate \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A futuristic cityscape at sunset with flying cars",
    "model": "flash",
    "aspectRatio": "16:9"
  }'

Parameters:

| Name | Type | Required | Default | Description | |------|------|----------|---------|-------------| | prompt | string | Yes | - | Text description of the image to generate | | model | string | No | flash | flash (fast, 1024px) or pro (high-quality, up to 4K) | | aspectRatio | string | No | 1:1 | Output aspect ratio | | imageSize | string | No | 1K | 1K, 2K, or 4K (4K only with pro model) |

Aspect Ratios:

| Ratio | Use Case | |-------|----------| | 1:1 | Square (social media, icons) | | 16:9 | Landscape (presentations, banners) | | 9:16 | Portrait (mobile, stories) | | 4:3 | Standard landscape | | 3:4 | Standard portrait | | 21:9 | Ultra-wide (cinematic) | | 2:3, 3:2, 4:5, 5:4 | Various formats |

Response:

{
  "image": {
    "base64": "iVBORw0KGgoAAAANSUhEUgAA...",
    "mimeType": "image/png",
    "dataUrl": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA..."
  },
  "description": "A vibrant futuristic cityscape..."
}

Response Fields:

| Field | Description | |-------|-------------| | image.base64 | Base64-encoded image data | | image.mimeType | Image MIME type (typically image/png) | | image.dataUrl | Ready-to-use data URL for HTML/CSS | | description | Model's description of the generated image |

Common Workflows

Generate a Simple Image

curl -X POST https://api.eng0.ai/api/data/images/generate \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A cute robot holding a cup of coffee"
  }'

Generate High-Quality 4K Image

curl -X POST https://api.eng0.ai/api/data/images/generate \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Professional product photo of a sleek smartphone on marble surface",
    "model": "pro",
    "imageSize": "4K",
    "aspectRatio": "4:3"
  }'

Generate Social Media Banner

curl -X POST https://api.eng0.ai/api/data/images/generate \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Abstract gradient background with geometric shapes in blue and purple",
    "aspectRatio": "16:9"
  }'

Generate Mobile Story Image

curl -X POST https://api.eng0.ai/api/data/images/generate \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Cozy coffee shop interior with warm lighting",
    "aspectRatio": "9:16"
  }'

Using with Python

import requests
import base64
from pathlib import Path

BASE_URL = "https://api.eng0.ai/api/data"

def generate_image(
    prompt: str,
    model: str = "flash",
    aspect_ratio: str = "1:1",
    image_size: str = "1K"
) -> dict:
    """Generate an image from a text prompt."""
    response = requests.post(
        f"{BASE_URL}/images/generate",
        json={
            "prompt": prompt,
            "model": model,
            "aspectRatio": aspect_ratio,
            "imageSize": image_size
        }
    )
    return response.json()

def save_image(result: dict, filepath: str) -> None:
    """Save generated image to a file."""
    if "image" in result:
        image_data = base64.b64decode(result["image"]["base64"])
        Path(filepath).write_bytes(image_data)
        print(f"Saved to {filepath}")
    else:
        print(f"Error: {result.get('error', 'Unknown error')}")

# Example: Generate and save an image
result = generate_image(
    prompt="A serene mountain landscape at dawn with mist in the valley",
    aspect_ratio="16:9"
)
save_image(result, "landscape.png")

# Example: Generate high-quality product image
result = generate_image(
    prompt="Minimalist tech gadget on white background, studio lighting",
    model="pro",
    image_size="4K"
)
save_image(result, "product.png")

Using with Node.js

const fs = require('fs');

const BASE_URL = 'https://api.eng0.ai/api/data';

async function generateImage(prompt, options = {}) {
  const response = await fetch(`${BASE_URL}/images/generate`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      prompt,
      model: options.model || 'flash',
      aspectRatio: options.aspectRatio || '1:1',
      imageSize: options.imageSize || '1K'
    })
  });
  return response.json();
}

function saveImage(result, filepath) {
  if (result.image) {
    const buffer = Buffer.from(result.image.base64, 'base64');
    fs.writeFileSync(filepath, buffer);
    console.log(`Saved to ${filepath}`);
  } else {
    console.error('Error:', result.error || 'Unknown error');
  }
}

// Example usage
(async () => {
  const result = await generateImage(
    'A neon-lit cyberpunk street scene at night',
    { aspectRatio: '21:9' }
  );
  saveImage(result, 'cyberpunk.png');
})();

Prompt Tips

Be Specific

Bad:  "A dog"
Good: "A golden retriever puppy playing in autumn leaves, warm sunlight"

Include Style

"Oil painting style portrait of a woman in Renaissance clothing"
"Minimalist vector illustration of a mountain range"
"Photorealistic close-up of a dewdrop on a leaf"

Specify Lighting

"... with dramatic side lighting"
"... golden hour sunlight"
"... soft diffused studio lighting"

Add Context

"... in the style of Studio Ghibli"
"... professional product photography"
"... vintage 1970s film aesthetic"

Model Comparison

| Feature | Flash | Pro | |---------|-------|-----| | Speed | Fast | Slower | | Max Resolution | 1024px | 4K | | Complex Prompts | Good | Excellent | | Text Rendering | Good | Sharp | | Best For | Quick iterations, previews | Final assets, print |

When to use Flash:

Rapid prototyping
Social media content
High-volume generation
When speed matters

When to use Pro:

Professional/commercial use
Print materials
Complex compositions
When quality matters

Error Handling

No Image Generated:

{
  "error": "No image generated",
  "message": "SAFETY"
}

This occurs when the prompt triggers content safety filters.

Invalid Parameters:

{
  "error": "Invalid parameters",
  "message": "Missing required parameter: prompt"
}

Important Notes

All generated images include invisible SynthID watermarking
Images are generated server-side; base64 responses can be large
The pro model takes longer but produces higher quality
4K resolution is only available with the pro model
Content safety filters may block certain prompts

Agent Skills: Nano Banana - Image Generation API

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