gemini-3.1-flash-image-preview (Chat Format)

POST

/v1/chat/completions

Google's latest Gemini image generation model, supporting text-to-image and image-to-image. Simply pass the image URL into image_url.
Supported models:
gemini-2.5-flash-image
gemini-3-pro-image-preview
gemini-3.1-flash-image-preview

Note:
1.
We have adapted the API format to be compatible with OpenAI API format, with response in markdown. This model does not support streaming
2.
This model automatically performs contextual image editing based on the conversation history provided

Please check pricing at: https://302.ai/price/

Request

Header Params

Body Params application/json

Example

{
    "model": "gemini-3.1-flash-image-preview",
    "stream": false,
    "messages": [
        {
            "role": "user",
            "content": [
                {
                    "type": "text",
                    "text": "Convert this image to a realistic version"
                },
                {
                    "type": "image_url",
                    "image_url": {
                        "url": "https://s2.loli.net/2024/02/01/QSWVdw9bX56gj7O.jpg"
                    }
                }
            ]
        }
    ]
}

Request Code Samples

Shell

JavaScript

Java

Swift

PHP

Python

HTTP

Objective-C

Ruby

OCaml

Dart

curl --location --request POST 'https://api.302.ai/v1/chat/completions' \
--header 'Accept: application/json' \
--header 'Authorization: Bearer ' \
--header 'Content-Type: application/json' \
--data-raw '{
    "model": "gemini-3.1-flash-image-preview",
    "stream": false,
    "messages": [
        {
            "role": "user",
            "content": [
                {
                    "type": "text",
                    "text": "Convert this image to a realistic version"
                },
                {
                    "type": "image_url",
                    "image_url": {
                        "url": "https://s2.loli.net/2024/02/01/QSWVdw9bX56gj7O.jpg"
                    }
                }
            ]
        }
    ]
}'

Responses

🟢200OK

application/json

Body

Example

{
    "id": "chatcmpl-123",
    "object": "chat.completion",
    "created": 1677652288,
    "choices": [
        {
            "index": 0,
            "message": {
                "role": "assistant",
                "content": "\n\nHello there, how may I assist you today?"
            },
            "finish_reason": "stop"
        }
    ],
    "usage": {
        "prompt_tokens": 9,
        "completion_tokens": 12,
        "total_tokens": 21
    }
}

Modified at 2026-02-26 19:06:05

gemini-3.1-flash-image-preview (Original Format - Image Editing)

gemini-3.1-flash-image-preview (Sync Per-Request - Text to Image)