Core API

Image Generation

Generate images from text prompts with automatic prompt enhancement.

Generate images from text prompts. Lunaby API automatically enhances prompts before sending to the model for best results. Blacklisted content will be rejected.

Endpoint#

POST /v1/images/generations

Request Parameters#

Parameter	Type	Required	Default	Description
`prompt`	`string`	Yes	—	Image description. Prompt is automatically enhanced before sending to model.
`model`	`string`	No	`lunaby-vision`	Image generation model.
`aspect_ratio`	`string`	No	`1:1`	Aspect ratio: '1:1' \| '16:9' \| '9:16' \| '4:3' \| '3:4' \| '21:9'.
`output_format`	`string`	No	`png`	Output format: 'png' \| 'jpeg' \| 'webp'.
`seed`	`integer`	No	—	Seed for reproducible results.
`negative_prompt`	`string`	No	—	Describe what should NOT appear in the image.

Example — Save to file (Node.js)#

typescript

import Lunaby from 'lunaby-sdk';
import fs from 'fs';

const client = new Lunaby({ apiKey: process.env.LUNABY_API_KEY });

const result = await client.images.generateBuffer(
  'A beautiful Vietnamese landscape at golden hour',
  {
    aspect_ratio: '16:9',
    output_format: 'png',
    negative_prompt: 'blurry, low quality, dark',
    seed: 42,
  }
);

fs.writeFileSync('output.png', result.buffer);
console.log('Saved!');
console.log('Revised prompt:', result.revisedPrompt);
console.log('Tokens:', result.usage?.total_tokens);

Example — Get Base64#

typescript

const response = await client.images.generate(
  'A cute cat sitting on a keyboard',
  { aspect_ratio: '1:1' }
);

const b64 = response.data.data[0].b64_json;
const revised = response.data.data[0].revised_prompt;

// Use in HTML img tag
const imgSrc = `data:image/png;base64,${b64}`;

cURL#

bash

curl https://api.lunie.dev/v1/images/generations \
  -H "Authorization: Bearer $LUNABY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A beautiful sunset over the city",
    "aspect_ratio": "16:9",
    "output_format": "png"
  }'

Response#

json

{
  "created": 1742500000,
  "data": [{
    "b64_json": "iVBORw0KGgo...",
    "revised_prompt": "A stunning cinematic sunset over the cityscape..."
  }],
  "usage": {
    "prompt_tokens": 12,
    "completion_tokens": 0,
    "total_tokens": 12
  }
}

Content Policy: Prompts that violate safety policies will receive a 400 error with the message "Request contains disallowed content".