多模态工具

配置工具插件以输出图片、音频或视频，使知识库节点能够将多模态输出与文本一同向量化

本文档由 AI 自动翻译。如有任何不准确之处，请参考 英文原版。

在知识流水线中，知识库节点支持两种多模态数据格式的入参：multimodal-Parent-Child 和 multimodal-General。

为使知识库节点能够识别并向量化工具插件输出的多模态数据（如文字、图片、音频或视频），需完成两项配置：

• 在工具代码文件中 ：调用工具会话接口上传文件并构造 files 对象。
• 在工具提供者 YAML 文件中 ：将 output_schema 声明为 multimodal-Parent-Child 或 multimodal-General。

上传并构造文件对象

处理图片等多模态数据时，需先通过 Dify 的工具会话上传文件，以获取文件元数据。

以下示例取自 Dify 官方插件 Dify Extractor ，展示如何上传文件并构造 files 对象。

# Upload the file using the tool session
file_res = self._tool.session.file.upload(
    file_name,   # filename
    file_blob,   # file binary data
    mime_type,   # MIME type, e.g., "image/png"
)

# Generate a Markdown image reference using the file preview URL
image_url = f"![image]({file_res.preview_url})"

上传接口会返回一个 UploadFileResponse 对象，包含文件信息：

from enum import Enum
from pydantic import BaseModel

class UploadFileResponse(BaseModel):
    class Type(str, Enum):
        DOCUMENT = "document"
        IMAGE = "image"
        VIDEO = "video"
        AUDIO = "audio"

        @classmethod
        def from_mime_type(cls, mime_type: str):
            if mime_type.startswith("image/"):
                return cls.IMAGE
            if mime_type.startswith("video/"):
                return cls.VIDEO
            if mime_type.startswith("audio/"):
                return cls.AUDIO
            return cls.DOCUMENT
    id: str
    name: str
    size: int
    extension: str
    mime_type: str
    type: Type | None = None
    preview_url: str | None = None

可将文件信息（如 name、size、extension、mime_type 等）映射到多模态输出结构中的 files 字段。

multimodal_parent_child_structure

{
    "$id": "https://dify.ai/schemas/v1/multimodal_parent_child_structure.json",
    "$schema": "http://json-schema.org/draft-07/schema#",
    "version": "1.0.0",
    "type": "object",
    "title": "Multimodal Parent-Child Structure",
    "description": "Schema for multimodal parent-child structure (v1)",
    "properties": {
        "parent_mode": {
        "type": "string",
        "description": "The mode of parent-child relationship"
        },
        "parent_child_chunks": {
        "type": "array",
        "items": {
            "type": "object",
            "properties": {
            "parent_content": {
                "type": "string",
                "description": "The parent content"
            },
            "files": {
                "type": "array",
                "items": {
                "type": "object",
                "properties": {
                    "name": {
                    "type": "string",
                    "description": "file name"
                    },
                    "size": {
                    "type": "number",
                    "description": "file size"
                    },
                    "extension": {
                    "type": "string",
                    "description": "file extension"
                    },
                    "type": {
                    "type": "string",
                    "description": "file type"
                    },
                    "mime_type": {
                    "type": "string",
                    "description": "file mime type"
                    },
                    "transfer_method": {
                    "type": "string",
                    "description": "file transfer method"
                    },
                    "url": {
                    "type": "string",
                    "description": "file url"
                    },
                    "related_id": {
                    "type": "string",
                    "description": "file related id"
                    }
                },
                "required": ["name", "size", "extension", "type", "mime_type", "transfer_method", "url", "related_id"]
                },
                "description": "List of files"
            },
            "child_contents": {
                "type": "array",
                "items": {
                "type": "string"
                },
                "description": "List of child contents"
            }
            },
            "required": ["parent_content", "child_contents"]
        },
        "description": "List of parent-child chunk pairs"
        }
    },
    "required": ["parent_mode", "parent_child_chunks"]
}

{
    "$id": "https://dify.ai/schemas/v1/multimodal_general_structure.json",
    "$schema": "http://json-schema.org/draft-07/schema#",
    "version": "1.0.0",
    "type": "array",
    "title": "Multimodal General Structure",
    "description": "Schema for multimodal general structure (v1) - array of objects",
    "properties": {
        "general_chunks": {
        "type": "array",
        "items": {
            "type": "object",
            "properties": {
            "content": {
                "type": "string",
                "description": "The content"
            },
            "files": {
                "type": "array",
                "items": {
                "type": "object",
                "properties": {
                    "name": {
                    "type": "string",
                    "description": "file name"
                    },
                    "size": {
                    "type": "number",
                    "description": "file size"
                    },
                    "extension": {
                    "type": "string",
                    "description": "file extension"
                    },
                    "type": {
                    "type": "string",
                    "description": "file type"
                    },
                    "mime_type": {
                    "type": "string",
                    "description": "file mime type"
                    },
                    "transfer_method": {
                    "type": "string",
                    "description": "file transfer method"
                    },
                    "url": {
                    "type": "string",
                    "description": "file url"
                    },
                    "related_id": {
                    "type": "string",
                    "description": "file related id"
                    }
                },
                "description": "List of files"
            }
            }
            },
            "required": ["content"]
        },
        "description": "List of content and files"
        }
    }
}

声明多模态输出结构

Dify 官方的 JSON Schema 定义了多模态数据的结构。

为使知识库节点识别插件的多模态输出类型，需在插件的提供者 YAML 文件中将 output_schema 下的 result 字段指向对应的官方 Schema URL。

output_schema:
  type: object
  properties:
    result:
      # multimodal-Parent-Child
      $ref: "https://dify.ai/schemas/v1/multimodal_parent_child_structure.json"
      
      # multimodal-General
      # $ref: "https://dify.ai/schemas/v1/multimodal_general_structure.json"

例如，使用 multimodal-Parent-Child 的完整 YAML 配置如下：

identity:
  name: multimodal_tool
  author: langgenius
  label:
    en_US: multimodal tool
    zh_Hans: 多模态提取器
    pt_BR: multimodal tool
description:
  human:
    en_US: Process documents into multimodal-Parent-Child chunk structures
    zh_Hans: 将文档处理为多模态父子分块结构
    pt_BR: Processar documentos em estruturas de divisão pai-filho
  llm: Processes documents into hierarchical multimodal-Parent-Child chunk structures

parameters:
  - name: input_text
    human_description:
      en_US: The text you want to chunk.
      zh_Hans: 输入文本
      pt_BR: Conteúdo de Entrada
    label:
      en_US: Input Content
      zh_Hans: 输入文本
      pt_BR: Conteúdo de Entrada
    llm_description: The text you want to chunk.
    required: true
    type: string
    form: llm

output_schema:
  type: object
  properties:
    result:
      $ref: "https://dify.ai/schemas/v1/multimodal_parent_child_structure.json"
extra:
  python:
    source: tools/parent_child_chunk.py