# Image generation

> POST /v1/images/generations: prompts, resolutions, aspect ratios, pixel sizes, response formats and prices.

Source: https://zurelay.com/docs/images

Make pictures from a prompt with OpenAI’s Images API: Nano Banana and GPT Image, one call each.

`POST /v1/images/generations`

| Model | ID | Sizes and prices | Reference images |
| --- | --- | --- | --- |
| [Nano Banana Pro](https://zurelay.com/models/nano-banana-pro) | `nano-banana-pro` | 1K and 2K $0.035 · 4K $0.065 | up to 14 |
| [Nano Banana 2](https://zurelay.com/models/nano-banana-2) | `nano-banana-2` | 1K $0.025 · 2K $0.034 · 4K $0.058 | up to 14 |
| [GPT Image 2.5 Flare](https://zurelay.com/models/gpt-image-2.5-flare) | `gpt-image-2.5-flare` | $0.02 an image | up to 16 |
| [GPT Image 2.5 Sunburst](https://zurelay.com/models/gpt-image-2.5-sunburst) | `gpt-image-2.5-sunburst` | $0.02 an image | up to 16 |
| [GPT Image 2](https://zurelay.com/models/gpt-image-2) | `gpt-image-2` | $0.02 an image | up to 16 |

## Make an image

**Python** (`main.py`):

```python
import os
from openai import OpenAI

client = OpenAI(base_url="https://api.zurelay.com/v1", api_key=os.environ["ZURELAY_API_KEY"])

result = client.images.generate(
    model="nano-banana-pro",
    prompt="A red fox curled up asleep in fresh snow at dawn, soft golden light, 85mm photo",
    size="2K",
    extra_body={
      "aspect_ratio": "3:2"
    },
)
print(result.data[0].url)
```

**Node.js** (`index.mjs`):

```javascript
import OpenAI from "openai";

const client = new OpenAI({ baseURL: "https://api.zurelay.com/v1", apiKey: process.env.ZURELAY_API_KEY });

const result = await client.images.generate({
  "model": "nano-banana-pro",
  "prompt": "A red fox curled up asleep in fresh snow at dawn, soft golden light, 85mm photo",
  "size": "2K",
  "aspect_ratio": "3:2"
});
console.log(result.data[0].url);
```

**cURL**:

```bash
curl https://api.zurelay.com/v1/images/generations \
  -H "Authorization: Bearer $ZURELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "nano-banana-pro",
  "prompt": "A red fox curled up asleep in fresh snow at dawn, soft golden light, 85mm photo",
  "size": "2K",
  "aspect_ratio": "3:2"
}'
```

Response:

```json
{
  "created": 1790870400,
  "data": [
    { "url": "https://...signed link, valid for 24 hours..." }
  ]
}
```

## Parameters

- `model` (string, required): An image model ID.
- `prompt` (string, required): What to make, up to 32,000 characters.
- `n` (integer): How many images, 1 to 4. They’re made at once; you pay for the ones delivered.
- `size` (string): Nano Banana: `1K`, `2K` or `4K` (or pixels like `2048x1152`, read as the nearest resolution and shape). GPT Image: pixels, such as `1024x1024` or `3840x2160`. Leave it out for the default.
- `aspect_ratio` (string): Nano Banana: `1:1`, `2:3`, `3:2`, `3:4`, `4:3`, `4:5`, `5:4`, `9:16`, `16:9` or `21:9`.
- `response_format` (string): `url` (default): a link valid for 24 hours. `b64_json`: the image itself, base64-encoded.
- `images` (array): Reference images to edit or work from. See [Image editing](https://zurelay.com/docs/image-editing).
- `quality, background, output_format` (string): GPT Image only: see the [GPT Image guide](https://zurelay.com/docs/gpt-image).

## Sizes

Nano Banana is priced by resolution and makes exactly the size asked for: an image that comes back smaller is retried, never delivered. At 1K:

| Aspect ratio | 1K | 2K | 4K |
| --- | --- | --- | --- |
| 1:1 | 1024 × 1024 | 2048 × 2048 | 4096 × 4096 |
| 2:3 | 848 × 1264 | 1696 × 2528 | 3392 × 5056 |
| 3:2 | 1264 × 848 | 2528 × 1696 | 5056 × 3392 |
| 3:4 | 896 × 1200 | 1792 × 2400 | 3584 × 4800 |
| 4:3 | 1200 × 896 | 2400 × 1792 | 4800 × 3584 |
| 4:5 | 928 × 1152 | 1856 × 2304 | 3712 × 4608 |
| 5:4 | 1152 × 928 | 2304 × 1856 | 4608 × 3712 |
| 9:16 | 768 × 1376 | 1536 × 2752 | 3072 × 5504 |
| 16:9 | 1376 × 768 | 2752 × 1536 | 5504 × 3072 |
| 21:9 | 1584 × 672 | 3168 × 1344 | 6336 × 2688 |

GPT Image costs the same at every size: `1024x1024`, `1536x1024`, `1024x1536`, `2048x2048`, `3840x2160`, `2160x3840`.

## Links and history

- Links in `url` are signed and work for 24 hours. Download what you want to keep.
- Images returned as `url` are also kept for 30 days in your dashboard’s [Library](https://zurelay.com/app/library), where you can download them, delete them, or use them as reference images. Images returned as `b64_json` aren’t stored.
- Prompts sent through the API aren’t stored with the images.

## Timing

Most images arrive in 10 to 60 seconds, longer at 4K. If an attempt stalls, the request is retried on another path automatically, so give your client a timeout of 10 minutes.

## When an image isn’t made

If the model declines a prompt (say, for its content policy), you get `400 image_not_generated` with the model’s reason, and you’re not charged. With `n` above 1, you get the images that were made and pay only for those.

- [Edit and combine images](https://zurelay.com/docs/image-editing): Reference images, up to 14 or 16 a request.
- [Nano Banana guide](https://zurelay.com/docs/nano-banana): Prompting, text in images, references.