You need to enable JavaScript to run this app.
Lake AI Service

Lake AI Service

Copy page
Download PDF
Multimodal deep thinking
Multimodal deep reasoning (Doubao-seed-2.0)
Copy page
Download PDF
Multimodal deep reasoning (Doubao-seed-2.0)

Operator introduction

Description

Provides deep reasoning capabilities for large models in multimodal scenarios
Uses models with deep reasoning capabilities to analyze and understand images, videos, or text, and returns structured text output. The operator automatically constructs a message structure that complies with multimodal model specifications. Users only need to provide image, video, or text data as per the convention to complete inference.

Key features

  • Deep reasoning mechanism: The model automatically decomposes questions and performs logical reasoning before answering, generating a reasoning chain (reasoning_content)
  • Multimodal scenario support: Supports image, video, and text input simultaneously, and automatically assembles multimodal messages
  • Input simplification mechanism: Supports multiple data sources such as local files, HTTP/HTTPS URLs, and TOS/S3 object storage. Visual understanding capabilities can be achieved through simple configuration.
  • Flexible reasoning mode: Supports controlling the deep reasoning mode (enabled / disabled / auto) via the thinking_type parameter, allowing flexible trade-offs between answer quality and performance

Input and output specifications

  • Input format:
    • Images (images): Supports string or list format
      • Supported data source types:
        • url: Network resource address, supports http/https/tos/s3. TOS/S3 will automatically generate a pre-signed URL
        • base64: Base64-encoded data
        • binary: Binary data (internally converted to Base64 encoding)
    • Videos (videos): Supports string or list format, with data source types consistent with images
    • Texts (texts): Supports string or list format, used as user prompts

(Mixing string and list types in the same field is not allowed)

  • Output format:
    • Default mode: Returns a struct type containing the following fields:
      • llm_result: The model's final answer content
      • reasoning_content: The model's reasoning chain / reasoning process
    • When the environment variable LAS_LLM_FINISH_REASON_CHECK=true is set, the struct will additionally include:
      • finish_reason: The reason for the model result ending, with possible values including:
        • stop: Normal termination
        • length: Exceeded token limit
        • content_filter: Triggered content filtering policy
    • When the environment variable LAS_LLM_BOTS_REFERENCES=true is set, the struct will additionally include:
      • references: Retrieval results or external knowledge information referenced by the model, facilitating downstream transmission and parsing

Enhanced model capabilities

  • Chain-of-thought visualization: The reasoning_content field outputs the model's reasoning process, making it easier to observe and review.
  • Result reliability control: The finish_reason field identifies abnormal termination scenarios, such as length truncation or content filtering.
  • Multimodal understanding: Supports mixed input parsing for images, videos, and text, suitable for complex multimodal scenarios.

Caution and prerequisites

Details

Caution and prerequisites

Costs

Before calling an operator, you need to understand the model invocation costs associated with using the operator. For details, see Large model invocation billing.

Authentication (API Key)

Before calling an operator, you need to generate an API Key for operator invocation. It is recommended to configure the API Key as an environment variable to ensure safer operator calls. For details, see Obtain and configure API Key.

BaseURL

Before calling an operator, you need to determine the BaseURL for operator invocation based on the region where your current LAS service is deployed. This is used to configure the path parameter values for operator calls.
For details, see Obtain the Base URL. The Examples below are for reference only; when making actual calls, replace the path values with those corresponding to your region.

Rest API invocation

Chat

Interface description

Use the Chat interface to invoke the doubao-seed-2.0 model for multimodal understanding.
Supported models and versions:

  • doubao-seed-2-0-pro-260215
  • doubao-seed-2-0-lite-260215
  • doubao-seed-2-0-mini-260215

Request parameters

Parameter

Type

Required

Example value

Description

model

string

Yes

doubao-seed-2-0-pro-260215

Model name and version, model name-version. Supported
doubao-seed-2-0-pro-260215,
doubao-seed-2-0-lite-260215,
doubao-seed-2-0-mini-260215

messages

list of chat_message

Yes

A list of messages that make up the conversation so far. Different models support different types of messages, such as text, images, videos, and many other types. For usage of this field, refer to 对话(Chat)APIthe messages parameter in the request body.

max_tokens

integer

No

10000

Value range: varies by model. For details, see .
Maximum length of the model's response (unit: token).

  • The model's response does not include chain-of-thought content. Model response = model output - model chain-of-thought (if any).
  • The total length of output tokens is also limited by the model's context length.

max_completion_tokens

integer

No

10000

For supported models and usage instructions for this field, see .

Value range: [0, 64k].
Controls the maximum length of the model's output (including both the model's response and chain-of-thought content, unit: token). After configuring this parameter, the model can output ultra-long content. The max_tokens parameter (default value 4k) becomes invalid, and the model outputs content (response and chain-of-thought) as needed until it reaches the value set by max_completion_tokens.
Cannot be set simultaneously with the max_tokens field; doing so will result in an error.

stop

list of string

No

The default value is null.
The model will stop generating when it encounters any string specified in the stop field; the word itself will not be output. Supports up to 4 strings.

Deep thinking capability model does not support this field.

frequency_penalty

float

No

1.0

Value range: [-2.0, 2.0]. Frequency penalty coefficient. If the value is positive, new tokens are penalized based on their frequency in the text, reducing the likelihood of the model repeating tokens verbatim.

presence_penalty

float

No

1.0

Value range: [-2.0, 2.0]. Presence penalty coefficient. If the value is positive, new tokens are penalized based on whether they have appeared in the text so far, increasing the likelihood that the model discusses new topics.

temperature

float

No

1

Value range: [0, 2]. Sampling temperature. Controls the degree to which the probability distribution for each candidate word is smoothed when generating text. When set to 0, the model considers only the token with the highest log probability. Higher values (such as 0.8) make the output more random, while lower values (such as 0.2) make the output more focused and deterministic. It is generally recommended to adjust only one of temperature or top_p, not both.

top_p

float

No

0.5

Value range: [0, 1]. Nucleus sampling probability threshold. The model considers token results within the top_p probability mass. When set to 0, the model considers only the token with the highest log probability. 0.1 means only the top 10% of tokens by probability mass are considered; the higher the value, the greater the randomness in generation, the lower the value, the more deterministic the output. It is generally recommended to adjust only one of temperature or top_p, not both.

thinking

request_thinking

No

Controls whether the model enables deep thinking mode. Deep thinking mode is enabled by default and can be manually disabled. For usage of this field, refer to the 对话(Chat)APIthinking parameter in the request body.

response_format

request_response_format

No

The model's output must follow the format specified here. For usage of this field, refer to the 对话(Chat)APIresponse_format parameter in the request body.

tools

list of chat_tool

No

List of tools to be called, which can be included in the model's returned information. To enable the model to return tools to be called, configure this structure. For usage of this field, refer to the 对话(Chat)APItools parameter in the request body.

tool_choice

string or object

No

Only doubao-seed-1-6-*** and subsequent series models support this field.

For this request, check whether the model's returned information contains any tools to be invoked. When no tool is specified, none is the default value. If tools are present, auto is the default value.
The tool selection mode is a string.

  • none: The model's returned information must not contain any tools to be invoked.
  • required: The model's returned information must contain tools to be invoked. When selecting this option, please ensure that suitable tools exist to reduce the likelihood of model hallucinations.
  • auto: The model determines whether there are tools to be invoked in the returned information.

Tool invocation (object).

  • Specify the scope of tools to be invoked. Only the following model information is allowed in the model's returned information. When selecting this option, please ensure that the tool meets user requirements to reduce the likelihood of model hallucinations. tool_choice.name specifies the name of the tool to be invoked; tool_choice.type specifies the type of invocation.

Response parameters

Parameter name
Data type
Example value
Parameter description
id
string
0217426318107460cfa43dc3f3683b1de1c09624ff49085a457ac
Unique identifier for this request.
model
string
-
The actual model name and version used for this request.
created
integer
-
Unix timestamp (seconds) for the creation time of this request.
object
string
chat.completion
Fixed as chat.completion.
choices
list of choice
-
Model output content for this request.
usage
usage
-
Token usage for this request.

Examples

Request example

curl --location "https://operator.las.ap-southeast-1.volces.com/api/v1/chat/completions" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $$LAS_API_KEY" \
--data '{
    "messages": [
        {
            "role": "user",
            "content": [
                {
                    "type": "video_url",
                    "video_url": {
                        "url": "https://las-ai-cn-beijing.tos-cn-beijing.volces.com/*****/sample.mp4"
                    }
                },
                {
                    "type": "text",
                    "text": "视频里面有什么"
                }
            ]
        }
    ],
    "model": "doubao-seed-2-0-pro-260215"
}'

Response example

{
  "model": "doubao-seed-2-0-pro-260215",
  "usage": {
    "prompt_tokens": 3877,
    "completion_tokens": 493,
    "total_tokens": 4370,
    "prompt_tokens_details": {
      "cached_tokens": 0,
      "provisioned_tokens": null
    },
    "completion_tokens_details": {
      "reasoning_tokens": 354,
      "provisioned_tokens": null
    }
  },
  "created": 1772692173,
  "id": "0217726921599114f28f9638b6effb5ab036b3eddba1d5642ea3d",
  "choices": [
    {
      "finish_reason": "stop",
      "index": 0,
      "logprobs": null,
      "message": {
        "content": "视频展现的是海边惬意的户外场景:\n1. 核心内容:一位戴着浅米色宽檐帽、黑色墨镜的女士,穿着白色上衣+印花彩色半身裙,靠在白色建筑的墙角,坐在折叠椅上手风琴演奏,演奏时还伴随哼唱,状态十分放松。她的脚边放着一瓶饮用水,背景是蓝色的海面和远处的低矮岸线。\n2. 画面变化:过程中镜头逐渐向女士推近,能越来越清晰看到她演奏的细节和神态;后半段还有穿绿短袖、浅色长裤的路人从她旁边经过。\n整体氛围闲适,充满海滨区域的松弛感。",
        "reasoning_content": "\n用户现在需要描述视频里的内容对吧,首先先梳理场景:首先是户外,靠海的地方,有个白色建筑的墙角对吧?然后主角是个女士,戴着浅色宽檐帽,白上衣,花裙子,墨镜,坐在折叠椅上,正在拉手风琴,旁边地上放着瓶装水,背景是海和远处的岸。然后过程里她一边拉一边还在唱,镜头慢慢往她那边推近对吧?然后后面有路人经过,比如穿绿短袖浅色裤子的人从旁边走过,还有其他路人?哦对,整体氛围很悠闲,是海边的街头演奏那种感觉对吧?\n等下整理清楚:\n首先整体场景:这是在海边的户外,靠近一处白色建筑的墙角,地面是石质地,背景能看到蓝色的海面和远处的低矮陆地,天气晴朗。\n然后核心人物:一位女士坐在黑色折叠椅上,她戴着浅米色宽檐帽、黑色墨镜,穿白色上衣、印着花卉图案的彩色半身裙,脚上是黑色凉鞋,正演奏着手风琴,演奏的过程中她还在跟着哼唱,状态很放松悠闲。她脚边放着一瓶透明的饮用水,旁边还有琴盒类的黑色箱子。\n然后镜头变化:视频过程中镜头逐渐向这位演奏的女士推近,到后半段能清晰看到她演奏的细节和神态。\n最后还有小细节:视频后半段有路人从她旁边的建筑旁走过,比如一位穿薄荷绿短袖、浅卡其色长裤的女士从旁边经过。\n整个氛围很闲适,充满海边小镇的惬意感。\n对,这样说清楚就可以了。",
        "role": "assistant"
      }
    }
  ],
  "object": "chat.completion"
}

Responses

Interface description

Use the Responses interface to invoke the doubao-seed-2.0 model for multimodal understanding. Refer to the interface definition in Create a model response.
Supported models and versions:

  • doubao-seed-2-0-pro-260215
  • doubao-seed-2-0-lite-260215
  • doubao-seed-2-0-mini-260215

Examples

Request example

curl --location "https://operator.las.ap-southeast-1.volces.com/api/v1/responses" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $LAS_API_KEY" \
--data '{
    "input": [
        {
            "role": "user",
            "content": [
                {
                    "type": "input_video",
                    "video_url": "https://las-ai-cn-beijing.tos-cn-beijing.volces.com/*****/sample.mp4"
                },
                {
                    "type": "input_text",
                    "text": "视频里面有什么"
                }
            ]
        }
    ],
    "model": "doubao-seed-2-0-pro-260215"
}'

Response example

{
    "model": "doubao-seed-2-0-pro-260215",
    "usage": {
        "prompt_tokens": 3877,
        "completion_tokens": 493,
        "total_tokens": 4370,
        "prompt_tokens_details": {
            "cached_tokens": 0,
            "provisioned_tokens": null
        },
        "completion_tokens_details": {
            "reasoning_tokens": 354,
            "provisioned_tokens": null
        }
    },
    "created": 1772692173,
    "id": "0217726921599114f28f9638b6effb5ab036b3eddba1d5642ea3d",
    "choices": [
        {
            "finish_reason": "stop",
            "index": 0,
            "logprobs": null,
            "message": {
                "content": "视频展现的是海边惬意的户外场景:\n1. 核心内容:一位戴着浅米色宽檐帽、黑色墨镜的女士,穿着白色上衣+印花彩色半身裙,靠在白色建筑的墙角,坐在折叠椅上手风琴演奏,演奏时还伴随哼唱,状态十分放松。她的脚边放着一瓶饮用水,背景是蓝色的海面和远处的低矮岸线。\n2. 画面变化:过程中镜头逐渐向女士推近,能越来越清晰看到她演奏的细节和神态;后半段还有穿绿短袖、浅色长裤的路人从她旁边经过。\n整体氛围闲适,充满海滨区域的松弛感。",
                "reasoning_content": "\n用户现在需要描述视频里的内容对吧,首先先梳理场景:首先是户外,靠海的地方,有个白色建筑的墙角对吧?然后主角是个女士,戴着浅色宽檐帽,白上衣,花裙子,墨镜,坐在折叠椅上,正在拉手风琴,旁边地上放着瓶装水,背景是海和远处的岸。然后过程里她一边拉一边还在唱,镜头慢慢往她那边推近对吧?然后后面有路人经过,比如穿绿短袖浅色裤子的人从旁边走过,还有其他路人?哦对,整体氛围很悠闲,是海边的街头演奏那种感觉对吧?\n等下整理清楚:\n首先整体场景:这是在海边的户外,靠近一处白色建筑的墙角,地面是石质地,背景能看到蓝色的海面和远处的低矮陆地,天气晴朗。\n然后核心人物:一位女士坐在黑色折叠椅上,她戴着浅米色宽檐帽、黑色墨镜,穿白色上衣、印着花卉图案的彩色半身裙,脚上是黑色凉鞋,正演奏着手风琴,演奏的过程中她还在跟着哼唱,状态很放松悠闲。她脚边放着一瓶透明的饮用水,旁边还有琴盒类的黑色箱子。\n然后镜头变化:视频过程中镜头逐渐向这位演奏的女士推近,到后半段能清晰看到她演奏的细节和神态。\n最后还有小细节:视频后半段有路人从她旁边的建筑旁走过,比如一位穿薄荷绿短袖、浅卡其色长裤的女士从旁边经过。\n整个氛围很闲适,充满海边小镇的惬意感。\n对,这样说清楚就可以了。",
                "role": "assistant"
            }
        }
    ],
    "object": "chat.completion"
}

Error codes

HttpStatusCode

Breakdown

Error message

Description

400

Model.InvalidName

The model name is invalid.

The model name is invalid.

401

Authorization.Missing

Missing Authorization.

Missing Authorization.

401

ApiKey.Invalid

The api key is invalid.

The API key is invalid.

Last updated: 2026.05.22 11:37:03