Gemini-3.1-Pro-Preview - Generate Image (AI Model · By )

API Documentation

API Reference

Images

Generate Image

Supported Model Code

Loading models...

Gemini-3.1-Pro-Preview (gemini-3.1-pro-preview)

gemini-3.1-pro-preview0 models support this endpoint

gemini-3.1-pro-preview is the flagship multimodal model under the Gemini 3.1 architecture. It delivers state-of-the-art reasoning, deep context understanding, and seamless analysis across text, code, images, video, and audio. It is the premier choice for tackling the most complex and demanding enterprise agentic workflows. http://vwdv30vppp.feishu.cn/docx/FC8ZdnCiRo7WKRx6fMvcl0rGnlg

Generate image

https://api.modelstream.ai

POST/v1/images/generations

Authentication

BearerAuth

AuthenticationBearer <token>

All API requests must be authenticated using a Bearer token in the Authorization header. Please ensure your API key is active.Authorization: Bearer sk-xxxxxx

Parameter Location: Header Param

Request Body

application/json

These parameters come from the selected model form_schema. Switching models updates this list and the request example.

system_prompt?string

Global instructions or persona for the model.

Example Value: You are a helpful and expert assistant.Placeholder: e.g., You are a senior software architect...

prompt*string

RequiredExample Value: Hello! What can you do?Placeholder: Enter your question or instructions...

image_urls?array

Supports multi-image understanding (optional).

Value Range: 0 ≤ value ≤ 10

image_detail?string

Example Value: auto

Enum/Options:

Auto: autoLow: lowHigh: high

temperature?number

Higher values make output more random, lower more deterministic.

Example Value: 1Value Range: 0 ≤ value ≤ 2step: 0.1

top_p?number

Nucleus sampling threshold; an alternative to temperature.

Example Value: 1Value Range: 0 ≤ value ≤ 1step: 0.05

presence_penalty?number

Increases the tendency to talk about new topics.

Example Value: 0Value Range: -2 ≤ value ≤ 2step: 0.1

frequency_penalty?number

Reduces the likelihood of repeating the same text verbatim.

Example Value: 0Value Range: -2 ≤ value ≤ 2step: 0.1

max_tokens?number

Example Value: 4096Value Range: 1 ≤ value ≤ 65536

response_format?string

Example Value: text

Enum/Options:

Text: textJSON Object: json_object

stream?boolean

Example Value: true

Response Parameters

application/json

200apiDocs.responses.successGenerateImage

created?integer

Parameter description for Created

data?array

Parameter description for Data

curl -X POST "https://api.modelstream.ai/v1/images/generations" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "gemini-3.1-pro-preview",
  "messages": [
    {
      "role": "system",
      "content": "You are a senior software architect."
    },
    {
      "role": "user",
      "content": [
        {
          "type": "text",
          "text": "Describe this image and suggest improvements."
        },
        {
          "type": "image_url",
          "image_url": {
            "url": "https://example.com/sample.png",
            "detail": "high"
          }
        }
      ]
    }
  ],
  "temperature": 0.7,
  "top_p": 1,
  "presence_penalty": 0,
  "frequency_penalty": 0,
  "max_tokens": 4096,
  "stream": true
}'

{
  "created": 0,
  "data": [
    {
      "url": "string",
      "b64_json": "string",
      "revised_prompt": "string"
    }
  ]
}

API Documentation

API Reference

Images

Generate Image

Supported Model Code

Loading models...

Gemini-3.1-Pro-Preview (gemini-3.1-pro-preview)

gemini-3.1-pro-preview0 models support this endpoint

Generate image

https://api.modelstream.ai

POST/v1/images/generations

Authentication

BearerAuth

AuthenticationBearer <token>

All API requests must be authenticated using a Bearer token in the Authorization header. Please ensure your API key is active.Authorization: Bearer sk-xxxxxx

Parameter Location: Header Param

Request Body

application/json

These parameters come from the selected model form_schema. Switching models updates this list and the request example.

system_prompt?string

Global instructions or persona for the model.

Example Value: You are a helpful and expert assistant.Placeholder: e.g., You are a senior software architect...

prompt*string

RequiredExample Value: Hello! What can you do?Placeholder: Enter your question or instructions...

image_urls?array

Supports multi-image understanding (optional).

Value Range: 0 ≤ value ≤ 10

image_detail?string

Example Value: auto

Enum/Options:

Auto: autoLow: lowHigh: high

temperature?number

Higher values make output more random, lower more deterministic.

Example Value: 1Value Range: 0 ≤ value ≤ 2step: 0.1

top_p?number

Nucleus sampling threshold; an alternative to temperature.

Example Value: 1Value Range: 0 ≤ value ≤ 1step: 0.05

presence_penalty?number

Increases the tendency to talk about new topics.

Example Value: 0Value Range: -2 ≤ value ≤ 2step: 0.1

frequency_penalty?number

Reduces the likelihood of repeating the same text verbatim.

Example Value: 0Value Range: -2 ≤ value ≤ 2step: 0.1

max_tokens?number

Example Value: 4096Value Range: 1 ≤ value ≤ 65536

response_format?string

Example Value: text

Enum/Options:

Text: textJSON Object: json_object

stream?boolean

Example Value: true

Response Parameters

application/json

200apiDocs.responses.successGenerateImage

created?integer

Parameter description for Created

data?array

Parameter description for Data

curl -X POST "https://api.modelstream.ai/v1/images/generations" \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "gemini-3.1-pro-preview",
  "messages": [
    {
      "role": "system",
      "content": "You are a senior software architect."
    },
    {
      "role": "user",
      "content": [
        {
          "type": "text",
          "text": "Describe this image and suggest improvements."
        },
        {
          "type": "image_url",
          "image_url": {
            "url": "https://example.com/sample.png",
            "detail": "high"
          }
        }
      ]
    }
  ],
  "temperature": 0.7,
  "top_p": 1,
  "presence_penalty": 0,
  "frequency_penalty": 0,
  "max_tokens": 4096,
  "stream": true
}'

{
  "created": 0,
  "data": [
    {
      "url": "string",
      "b64_json": "string",
      "revised_prompt": "string"
    }
  ]
}

Gemini-3.1-Pro-Preview - Generate Image (AI Model · By ) | ModelStream