Gemini Image Generation

Endpoints

Gemini image models use the OpenAI-compatible image task endpoint:

POST /v1/images/generations/jobs
GET /v1/images/generations/jobs/{job_id}

The synchronous endpoint is also available when the client can wait for the result:

POST /v1/images/generations

Model IDs

Common model IDs include:

gemini-3.1-flash-image-preview
gemini-3-pro-image-preview

Use the model list endpoint to confirm the IDs available to the current API key.

Text-to-image

curl https://kaienapi.com/v1/images/generations/jobs \\
  -H "Authorization: Bearer <YOUR_API_KEY>" \\
  -H "Content-Type: application/json" \\
  -d '{
    "model": "gemini-3.1-flash-image-preview",
    "prompt": "Create a clean editorial illustration of a city at sunrise",
    "aspect_ratio": "16:9",
    "image_size": "1K"
  }'

Reference images

Pass one or more public image URLs in image:

{
  "model": "gemini-3.1-flash-image-preview",
  "prompt": "Use image 1 as the subject and image 2 as the color reference.",
  "image": [
    "https://oss.example.com/subject.jpg",
    "https://oss.example.com/style.jpg"
  ],
  "aspect_ratio": "4:3",
  "image_size": "2K"
}

Make sure reference URLs are public and will not expire before the task completes.

Reading results

Save the returned task ID and poll until the status is succeeded or failed. On success, read the data array. On failure, read error.message and preserve the full response for diagnosis. aspect_ratio controls the frame, while image_size controls the output tier. Supported values depend on the model, so keep the model’s error response when a combination is rejected.

Getting started

Images and video

Audio

AI tools

API Reference

Gemini Image Generation

Endpoints

Model IDs

Text-to-image

Reference images

Reading results

​Endpoints

​Model IDs

​Text-to-image

​Reference images

​Reading results

Endpoints

Model IDs

Text-to-image

Reference images

Reading results