GPT-Image-1.5 API Tutorial: Access OpenAI's Latest Image Model via NexaAPI (Python & JS)

OpenAI's GPT-Image-1.5 is here, and it's a significant upgrade over its predecessor. With improved photorealism, better text rendering, and enhanced instruction following, it's quickly becoming the go-to model for developers who need high-quality image generation.

This tutorial shows you how to access GPT-Image-1.5 through NexaAPI — giving you the same OpenAI quality at a fraction of the cost.

What's New in GPT-Image-1.5?

GPT-Image-1.5 brings significant improvements:

• Enhanced photorealism: More lifelike human faces and natural scenes
• Better text rendering: Accurate text in images (signs, labels, UI mockups)
• Improved instruction following: More precise prompt adherence
• Faster generation: Reduced latency compared to GPT-Image-1
• Better editing: More accurate image editing with inpainting

These improvements make it especially valuable for:

• Product photography and mockups
• Marketing materials with text
• UI/UX prototyping
• Content creation at scale

Why Use NexaAPI Instead of Direct OpenAI API?

While OpenAI's API is excellent, NexaAPI offers key advantages:

Feature	OpenAI Direct	NexaAPI
GPT-Image-1.5 pricing	~$0.04-0.12/image	$0.003/image
Access to other models	OpenAI only	56+ models
Free tier	$5 credit	Yes, no credit card
API style	OpenAI SDK	OpenAI-compatible

The pricing difference is substantial: 13-40x cheaper for the same model quality.

Python Tutorial

# Install: pip install nexaapi
from nexaapi import NexaAPI

client = NexaAPI(api_key='YOUR_API_KEY')

# Generate with GPT-Image-1.5
result = client.images.generate(
    model='gpt-image-1.5',  # check nexa-api.com for exact slug
    prompt='A professional headshot of a business executive, studio lighting, neutral background, photorealistic',
    size='1024x1024',
    quality='high'
)

print(result.url)  # Direct URL to generated image
# Cost: $0.003 per image

Image Editing with GPT-Image-1.5

from nexaapi import NexaAPI

client = NexaAPI(api_key='YOUR_API_KEY')

# Edit an existing image
result = client.images.edit(
    model='gpt-image-1.5',
    image_url='https://example.com/product-photo.jpg',
    prompt='Change the background to a modern office setting, keep the product in focus',
)

print(result.url)

Batch Generation for Marketing

from nexaapi import NexaAPI

client = NexaAPI(api_key='YOUR_API_KEY')

# Generate a set of marketing images
campaign_prompts = [
    'Hero image for a SaaS dashboard product, clean UI screenshot on MacBook, white background',
    'Team collaboration scene in modern office, diverse group, natural lighting',
    'Abstract technology background with circuit patterns, blue gradient, 16:9 ratio'
]

for prompt in campaign_prompts:
    result = client.images.generate(
        model='gpt-image-1.5',
        prompt=prompt,
        size='1792x1024'  # 16:9 for hero images
    )
    print(f'Generated: {result.url}')
    # Total cost for 3 images: $0.009

JavaScript Tutorial

// Install: npm install nexaapi
import NexaAPI from 'nexaapi';

const client = new NexaAPI({ apiKey: 'YOUR_API_KEY' });

async function generateImage() {
  const result = await client.images.generate({
    model: 'gpt-image-1.5',  // check nexa-api.com for exact slug
    prompt: 'A professional headshot of a business executive, studio lighting, neutral background, photorealistic',
    size: '1024x1024',
    quality: 'high'
  });

  console.log('Image URL:', result.url);
  return result.url;
}

generateImage();

Express.js Image Generation API

import express from 'express';
import NexaAPI from 'nexaapi';

const app = express();
const client = new NexaAPI({ apiKey: process.env.NEXA_API_KEY });

app.use(express.json());

app.post('/generate', async (req, res) => {
  const { prompt, size = '1024x1024' } = req.body;

  if (!prompt) {
    return res.status(400).json({ error: 'Prompt is required' });
  }

  try {
    const result = await client.images.generate({
      model: 'gpt-image-1.5',
      prompt,
      size
    });

    res.json({ 
      url: result.url,
      cost: '$0.003'
    });
  } catch (error) {
    res.status(500).json({ error: error.message });
  }
});

app.listen(3000, () => console.log('Image API running on port 3000'));

Prompt Tips for GPT-Image-1.5

GPT-Image-1.5 excels with:

1. Detailed descriptions: More detail = better results
2. Style references: "photorealistic", "oil painting", "digital art", "watercolor"
3. Lighting specifications: "studio lighting", "natural light", "dramatic shadows"
4. Composition guidance: "rule of thirds", "centered subject", "wide angle"

High-quality prompt examples:

• "A cozy coffee shop interior, morning light streaming through windows, people working on laptops, photorealistic, warm tones"
• "Product mockup: iPhone 16 with custom app UI showing a fitness tracker, white background, professional product photography"
• "Abstract representation of artificial intelligence: neural network nodes glowing blue, dark background, 4K digital art"

Cost Calculator

At $0.003/image with NexaAPI:

Monthly Volume	NexaAPI Cost	OpenAI Direct (est.)
1,000 images	$3	$40-120
10,000 images	$30	$400-1,200
100,000 images	$300	$4,000-12,000

Get Started Free

• 🚀 Get your free API key: nexa-api.com
• 🆓 Try on RapidAPI (free tier): rapidapi.com/user/nexaquency
• 🐍 Python SDK: pip install nexaapi | PyPI
• 📦 Node.js SDK: npm install nexaapi | npm

Conclusion

GPT-Image-1.5 is OpenAI's best image model yet, and NexaAPI makes it accessible at a price point that makes production use viable for any team. Whether you're building a content platform, an e-commerce tool, or a creative app, you can now generate thousands of high-quality images for just a few dollars.

Start for free at nexa-api.com — no credit card required.