Image Generation

Google image generation models are exposed through /v1/images/generations.

Text-to-image

curl https://llmtr.com/v1/images/generations \
  -H "Authorization: Bearer sk_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3.1-flash-image-preview",
    "prompt": "A minimalist modern workspace with warm light",
    "size": "1K",
    "aspect_ratio": "16:9",
    "n": 1
  }'

Image-to-image (reference image)

Upload a source image via Files API first, then pass the file_id:

curl https://llmtr.com/v1/images/generations \
  -H "Authorization: Bearer sk_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3.1-flash-image-preview",
    "prompt": "Turn this product photo into an ad poster",
    "file_id": "file_xxx",
    "size": "1K",
    "aspect_ratio": "1:1",
    "n": 1
  }'

Parameters

Field	Values
size	512, 1K, 2K
aspect_ratio	1:1, 3:4, 4:3, 9:16, 16:9
n	1-4
file_id	Optional reference image

Response

{
  "created": 1739200000,
  "data": [
    {
      "b64_json": "iVBORw0KGgoAAAANSUhEUgAA...",
      "revised_prompt": "A minimalist modern..."
    }
  ]
}

Pricing

Billed per image by native unit. See the model card in Dashboard > Models.