black-forest-labs/flux-kontext-max/multi API

This document introduces the input and output parameters for calling the black-forest-labs/flux-kontext-max/multi model API. Please refer to this reference when using the interface.

Request Parameters

Request Body

Field Name	Type	Required	Default	Description
prompt	string	Conditionally Required	-	Prompt words
model	string	Required	-	The model name used for this request, which in this case is `black-forest-labs/flux-kontext-max/multi`.
images	array(string)	Required	-	Multiple image edits, base64 data or image link http://xxx
n	int	Optional	1	The number of images to generate, ranging from 1 to 4
aspect_ratio	string	Optional	”1:1”	The aspect ratio of the image, formatted as “width:height”, such as “16:9” or “1:1”
seed	int	Optional	-1	Random seed used to control the randomness of the model’s generated content. To keep content consistent, use the same seed value.
steps	int	Optional	20	Number of inferences, ranging from 1 to 50
guidance_scale	float	Optional	2.5	The consistency between the model’s output and the prompt, i.e., the freedom of the generated image; the greater the value, the less freedom the model has, and the stronger the correlation with the user’s input prompts. Value range [1, 10].
negative_prompt	string	Optional	-	Negative prompts used to specify content that should not appear in the generated image
response_format	string	Optional	”url”	Specify the format for returning the generated image, default is `url`, or can be `b64_json`

Response Parameters

Field Name	Type	Description
created	`integer`	Unix timestamp (in seconds) of the request creation time.
data	`array`	Information about the output image, including the download URL or Base64. • When the format is specified as URL, the subfield is URL; • When the format is specified as b64_json, the subfield is b64_json. Note: The link expires within 7 days after it is generated, please save the image in time.
error	`Object`	Error information object
error.code	`string`	Error code
error.message	`string`	Error message
error.param	`string`	Request ID

Example

OPENAI Compatible Interface

POST https://api.umodelverse.ai/v1/images/generations

Synchronous Request


curl --location 'https://api.umodelverse.ai/v1/images/generations' \
--header "Authorization: Bearer $MODELVERSE_API_KEY" \
--header 'Content-Type: application/json' \
--data '{
    "model": "black-forest-labs/flux-kontext-max/multi",
    "prompt": "Convert to quick pencil sketch",
    "images": [
        "https://umodelverse-inference.cn-wlcb.ufileos.com/ucloud-maxcot.jpg",
        "data:image/png;base64,{image_base64_string}"
    ]
}'


import os
from openai import OpenAI
 
client = OpenAI(
    base_url=os.getenv("BASE_URL", "https://api.umodelverse.ai/v1"),
    api_key=os.getenv("API_KEY", "$MODELVERSE_API_KEY")
)
 
response = client.images.generate(
    model="black-forest-labs/flux-kontext-max/multi",
    prompt="Convert to quick pencil sketch",
    extra_body={
        "images": [
            "https://umodelverse-inference.cn-wlcb.ufileos.com/ucloud-maxcot.jpg",
            "data:image/png;base64,{image_base64_string}"
        ]
    }
)
 
print(response.data[0].url)

Response


{
  "created": 1750667997,
  "data": [
    {
      "url": "https://xxxxx/xxxx.png",
      "b64_json": "data:image/png;base64,{image_base64_string}"
    }
  ],
  "usage": {
    "input_tokens_details": {}
  }
}


{
  "error": {
    "message": "error_message",
    "type": "error_type",
    "param": "request_id",
    "code": "error_code"
  }
}