Image Generation

Introduction

The image generation API supports text-to-image, image-to-image, image editing, and more. Through a unified API interface, you can call multiple mainstream image generation models including Gemini, Doubao Seedream, GPT Image, and Qwen.

Authentication

Bearer Token, e.g., Bearer sk-xxxxxxxxxx

Request Parameters

model

string

required

Model identifier, supported models include:

Qwen series: qwen-image-plus, qwen-image-edit-plus, etc.
GPT Image series: gpt-image-1, etc.
Doubao Seedream series: doubao-seedream-3-0-t2i-250415, doubao-seedream-4-0-250828, doubao-seedream-4-5-251128, doubao-seededit-3-0-i2i-250628, etc.
Gemini series: gemini-2.5-flash-image (Nano Banana), gemini-3-pro-image-preview (Nano Banana Pro), etc.

prompt

string

Text-to-image prompt

response_format

string

Response format: b64_json or urlNote: Different models have different support for response_format:

Qwen series: Supports both b64_json and url
GPT Image series: Only supports b64_json format
Doubao Seedream series: Usually returns URL links
Gemini series: Only supports b64_json format

contents

array

Multi-turn content for image-to-image or context conversations

Basic Examples

Gemini
Doubao Seedream
GPT Image
Qwen

Text-to-Image
Image-to-Image

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "gemini-2.5-flash-image",
  "prompt": "A cute orange kitten sitting in a garden, sunny day, high quality photography",
  "size": "16:9",
  "quality": "high",
  "n": 1,
  "temperature":1.1,
  "top_p":0.95,
  "response_format": "b64_json",
  "image_size": "2K",
  "mime_type": "image/png",
  "response_modalities": "image"
}'

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "gemini-2.5-flash-image",
  "size": "16:9",
  "quality": "high",
  "image_size": "3K",
  "temperature":1.1,
  "top_p":0.95,
  "response_format": "b64_json",
  "contents": [
    {
      "role": "user",
      "parts": [
        {"text": "Generate an aerial view of Canton Tower based on this image"},
        {"image": "data:image/png;base64,iVBORw0KGgoAAxxxx..."}
      ]
    }
  ]
}'

Text-to-Image
Image-to-Image

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "doubao-seedream-4-0-250828",
  "prompt": "A cute orange kitten sitting in a garden, sunny day, high quality photography",
  "size": "2048x2048",
  "watermark": false,
  "seed": 12345,
  "optimize_prompt_options": {
    "mode": "standard"
  }
}'

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "doubao-seedream-4-0-250828",
  "prompt": "Transform this image into oil painting style",
  "size": "2048x2048",
  "watermark": false,
  "seed": 12345,
  "contents": [
    {
      "role": "user",
      "parts": [
        {"image": "data:image/png;base64,iVBORw0KGgoAAxxxx..."},
        {"text": "Transform this image into oil painting style"}
      ]
    }
  ]
}'

Text-to-Image
Image-to-Image

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "gpt-image-1",
  "prompt": "A cute orange kitten sitting in a garden, sunny day, high quality photography",
  "size": "1024x1024",
  "quality": "high",
  "n": 1
}'

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "gpt-image-1",
  "prompt": "Transform this image into oil painting style",
  "size": "1024x1024",
  "quality": "high",
  "input_fidelity": "medium",
  "n": 1,
  "image": "data:image/png;base64,iVBORw0KGgoAAxxxx..."
}'

Text-to-Image

curl -X POST "https://console.mixroute.io/v1/images/generations" \
-H "Authorization: Bearer sk-xxxxxxxxxx" \
-H "Content-Type: application/json" \
-d '{
  "model": "qwen-image-plus",
  "input": {
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "text": "An elegant couplet hanging in a traditional Chinese hall"
          }
        ]
      }
    ]
  },
  "parameters": {
    "negative_prompt": "1",
    "prompt_extend": true,
    "seed": "4",
    "watermark": true
  }
}'

{
  "code": 200,
  "msg": "Success",
  "data": {
    "data": [
      {
        "url": "",
        "b64_json": "iVBORw0KGgoAAAANSUhEUgAABAAAAAQA...",
        "revised_prompt": ""
      }
    ],
    "created": 1757320007
  }
}

Model-Specific Parameters

Doubao Seedream

size

string

Image size, depends on model version:

doubao-seedream-4.0/4.5: 2048x2048, 2304x1728, etc. (2K/4K)
doubao-seedream-3.0: 1024x1024, 1152x864, etc.

watermark

boolean

Whether to add watermark

seed

integer

Random seed for controlling generation randomness. Range: 0 to 2147483647

guidance_scale

number

Guidance coefficient. Recommended range: 1.0-10.0, default: 2.5

sequential_image_generation

string

Sequential image generation switch: "disabled" (default) or "auto"

GPT Image

size

string

Image size: 1024x1024, 1024x1536, 1536x1024. Default: 1024x1024

quality

string

Image quality: "high", "medium", "low"

integer

Number of images to generate. Range: 1-10

input_fidelity

string

Input fidelity for image-to-image: "auto", "high", "medium", "low"

Gemini

size

string

Aspect ratio: 1:1, 3:2, 2:3, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9

image_size

string

Image size: 1K (default), 2K, 4K

mime_type

string

Output format: image/png (default), image/jpeg

Supported Models

Gemini Series

Model Name	Core Capabilities
`gemini-2.5-flash-image` (Nano Banana)	Text-to-image, image-to-image, multi-image fusion
`gemini-3-pro-image-preview` (Nano Banana Pro)	Higher quality output, text-to-image, image-to-image

Doubao Seedream Series

Model Name	Core Capabilities
`doubao-seedream-3-0-t2i-250415`	Text-to-image, seed control, guidance coefficient
`doubao-seedream-4-0-250828`	Text-to-image, image-to-image, multi-image fusion, 2K/4K
`doubao-seedream-4-5-251128`	Text-to-image, image-to-image, prompt optimization
`doubao-seededit-3-0-i2i-250628`	Image editing, style transfer

GPT Image Series

Model Name	Core Capabilities
`gpt-image-1`	Text-to-image, image-to-image, multi-image fusion
`gpt-image-1-mini`	Lower cost, faster speed

Qwen Series

Model Name	Core Capabilities
`qwen-image-plus`	Text-to-image, text rendering, prompt extension
`qwen-image-edit-plus`	Image editing, style transfer

FAQ

What image formats are supported?

Different models support different formats:

Qwen: JPEG, JPG, PNG, BMP, TIFF, WEBP, max 10MB
GPT Image: JPEG, PNG, GIF, WEBP, max 10MB
Doubao Seedream 4.x: JPEG, PNG, WEBP, BMP, TIFF, GIF, max 10MB
Gemini: PNG, JPEG, JPG, WEBP, max 7MB

How long are generated images valid?

Image URLs are valid for approximately 24 hours. It is recommended to download and save immediately after receiving the response.

Can I generate multiple images at once?

GPT Image: Use n parameter (1-10 images)
Doubao Seedream 4.x: Use sequential image generation (1-4 images)
Qwen: 1 image per request, make multiple concurrent requests for more

curl --request POST \
  --url https://console.mixroute.io/v1/images/generations \
  --header 'Authorization: Bearer sk-xxxxxxxxxx' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "seedream-4.0-base",
    "prompt": "A cute orange kitten sitting in a garden",
    "size": "1024x1024",
    "n": 1
  }'

{
  "created": 1709459123,
  "data": [
    {
      "url": "https://example.com/generated-image.png",
      "revised_prompt": "A cute orange kitten sitting in a garden"
    }
  ]
}

Popular Models

OpenAI SDK Usage

Text Series

Embedding Series

Image Series

Video Series

Others

Introduction

Authentication

Request Parameters

Basic Examples

Model-Specific Parameters

Doubao Seedream

GPT Image

Gemini

Supported Models

Gemini Series

Doubao Seedream Series

GPT Image Series

Qwen Series

FAQ

Popular Models

OpenAI SDK Usage

Text Series

Embedding Series

Image Series

Video Series

Others

​Introduction

​Authentication

​Request Parameters

​Basic Examples

​Model-Specific Parameters

​Doubao Seedream

​GPT Image

​Gemini

​Supported Models

​Gemini Series

​Doubao Seedream Series

​GPT Image Series

​Qwen Series

​FAQ

Introduction

Authentication

Request Parameters

Basic Examples

Model-Specific Parameters

Doubao Seedream

GPT Image

Gemini

Supported Models

Gemini Series

Doubao Seedream Series

GPT Image Series

Qwen Series

FAQ