Generate images from text descriptions using FLUX models running on GPUs in Groningen.

Image generation

POST /v1/images/generations

Request body

Parameter	Type	Description
`model`	string	Image model. Use `schnell`. Required
`prompt`	string	Text description of the image to generate. Required
`size`	string	Image dimensions. Default `1024x1024`.
`n`	integer	Number of images to generate. Default `1`.
`response_format`	string	`url` (default) or `b64_json` for base64-encoded image data.
`user`	string	Your own end-user identifier, for usage attribution. Max 128 characters. See Usage attribution.
`session_id`	string	Groups requests into one conversation or run. Max 128 characters. See Usage attribution.

Example request

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://router.appelon.ai/v1",
    api_key=os.environ["APPELON_API_KEY"]
)

response = client.images.generate(
    model="schnell",
    prompt="A serene Dutch landscape with windmills at sunset",
    size="1024x1024"
)

image_url = response.data[0].url
print(image_url)

import OpenAI from 'openai';

const client = new OpenAI({
  baseURL: 'https://router.appelon.ai/v1',
  apiKey: process.env.APPELON_API_KEY,
});

const response = await client.images.generate({
  model: 'schnell',
  prompt: 'A serene Dutch landscape with windmills at sunset',
  size: '1024x1024',
});

console.log(response.data[0].url);

Response

Returns an array of image objects with URLs or base64 data.

{
  "created": 1234567890,
  "data": [{
    "url": "https://..."
  }]
}

With response_format: "b64_json":

{
  "created": 1234567890,
  "data": [{
    "b64_json": "iVBORw0KGgoAAAANSUhEUgAA..."
  }]
}

Available models

Model	Speed	Best for
`schnell`	~2s	Fast generation, iteration, prototyping

dev (FLUX Dev) is retired. Requests for it return an error that points to schnell.

Supported sizes

FLUX supports flexible aspect ratios. Common sizes:

Size	Aspect ratio
`1024x1024`	1:1 (square)
`1024x768`	4:3 (landscape)
`768x1024`	3:4 (portrait)
`1280x720`	16:9 (widescreen)
`720x1280`	9:16 (mobile)