Flux 3 Klein

curl --request POST \
  --url https://api.poyo.ai/api/generate/submit \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "flux-3-klein",
  "input": {
    "prompt": "A red fox in fresh snow at sunrise",
    "size": "3:2",
    "resolution": "2K"
  }
}
'

{
  "code": 200,
  "data": {
    "task_id": "task-unified-1792468800-example",
    "status": "not_started",
    "created_time": "2026-10-20T12:00:00"
  }
}

{
  "error": {
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

Flux 3 Klein creates images from text and edits or combines reference images. Use it for product photography, illustrations, and reference-based compositions.

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Models

• flux-3-klein — Text-to-image generation
• flux-3-klein-edit — Image editing with up to 10 references

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Features

• Generate 1–4 images per request in PNG, JPEG, or WebP.
• Choose 1K, 2K, or 4K output with an aspect ratio or exact pixel dimensions.
• Edit or combine up to 10 reference images.

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Input modes

The generation model does not accept reference images. For editing, refer to images in their supplied order, such as “the first image”.

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Required parameters

• prompt (string): Non-empty description of the complete target image, including the subject, framing, background, lighting, and desired edits.
• image_urls (array of strings): Required for flux-3-klein-edit only. Supply 1–10 publicly accessible HTTP(S) reference image URLs.

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Optional parameters

• size (string): 1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3, or an exact WIDTHxHEIGHT value. Defaults to 1:1 in both modes.
• resolution (string): 1K, 2K, or 4K. Defaults to 1K; custom pixel dimensions require an explicit matching value.
• n (integer): Number of output images, from 1 through 4. Defaults to 1.
• output_format (string): png (default), jpeg, or webp.
• enable_safety_checker (boolean): Enable content safety checking. Defaults to true.

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Size

For an aspect ratio, resolution sets the long edge to 1024, 2048, or 4096 pixels. The short edge follows the requested ratio and is rounded to the nearest multiple of 16. For custom WIDTHxHEIGHT dimensions, each side must be 256–4096 pixels and divisible by 16. Supply resolution explicitly using the tier determined by the longer side: For example, size: "1536x1024" requires resolution: "2K".

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Examples

The OpenAPI examples include generation, reference editing, and custom dimensions.

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Notes

Keep all generation parameters inside input; callback_url belongs at the request’s top level.