Langchain basetool. We will use the default agent type here. Learn how to create custom tools for LangChain agents using functions, runnables, or subclassing BaseTool. Subclassing the BaseTool class provides more control over the tool’s behaviour and defines custom instance variables or propagates callbacks. Tools are components that can be called by agents to perform specific actions. BaseTool ¶ Note BaseTool implements the standard Runnable Interface. Args schema should be either: A subclass of pydantic. These methods are shown in the how to create custom tools guide, but we generally recommend using the @tool decorator for most cases. There are two ways to do this: either by using the Tool dataclass, or by subclassing the BaseTool class. See examples of tool attributes, schemas, decorators, and docstrings. Each tool has a description. Class hierarchy: BaseTool # class langchain_core. Initialize the tool. Aug 14, 2024 · class langchain_core. chat_models import ChatOpenAI from langchain. base. simple. g. # Construct the agent. Pydantic model class to validate and parse the tool’s input arguments. Oct 16, 2024 · LangChainでは、 @tool デコレーターなどで定義した関数を一度 BaseTool に変換し、その後、OpenAIやAnthropicなど各LLMモデル用のパラメータへと変換しています。 (@toolデコレーター => BaseTool => モデルのパラメタ) 関数名 -> name 関数の説明 -> description Nov 30, 2023 · Creating a custom tool in LangChain To define a custom tool in LangChain, you can use the Tool. tools. First, we show how to create completely new tools from scratch. param args_schema: Optional[Type[BaseModel]] = None ¶ Pydantic model class to validate and parse the tool’s input arguments. pydantic_v1 import BaseModel, Field from langchain. 🏃 The Runnable Interface has additional methods that are available on runnables, such as with_types, with_retry, assign, bind, get_graph, and more. agents import AgentType, Tool, initialize_agent, tool from langchain. Aug 3, 2024 · from langchain. Raises ValidationError if the input data cannot be parsed to form a valid model. Interface LangChain tools must implement. tools import BaseTool, StructuredTool, tool: BaseTool: This is a base class for tools in LangChain, which provides foundational functionalities for creating custom tools. The Tool. Dec 9, 2024 · langchain_core. from_function () method or subclass the BaseTool class. tools import BaseTool # Import things that are needed generically from langchain. tools # Tools are classes that an Agent uses to interact with the world. Q: Can I use previously defined string BaseTool 's with new agents built for StructuredTool ’s A: Yes! Structured tools don’t require new agent executors, and older tools are forwards compatible. 🏃. BaseTool [source] ¶ Bases: RunnableSerializable [Union [str, Dict, ToolCall], Any] Interface LangChain tools must implement. Initialize tool. Deprecated. Base class for all LangChain tools. The BaseTool class serves as the foundation for all tools in LangChain. tools import BaseTool, StructuredTool, tool Tool # class langchain_core. , by sub-classing the BaseTool class or by using StructuredTool. from_function () method lets you quickly create a tool from a simple function. Tool [source] # Bases: BaseTool Tool that takes in function or coroutine directly. BaseTool implements the standard Runnable Interface. BaseTool [source] # Bases: RunnableSerializable [Union [str, Dict, ToolCall], Any] Interface LangChain tools must implement. This abstract class defines the interface that all LangChain tools must implement. Agent uses the description to choose the right tool for the job. or - A subclass of pydantic. Class hierarchy: # Import things that are needed generically from langchain import LLMMathChain, SerpAPIWrapper from langchain. May 17, 2025 · BaseTool 是 LangChain 框架中的抽象基类，用于创建语言 模型 （尤其在基于代理的系统中）可调用的工具。 它提供标准接口，支持输入验证、错误处理、工件输出及与 LangChain 可运行对象的集成。 LangChain has a few other ways to create tools; e. Once RunnableSerializable --> BaseTool --> <name>Tool # Examples: AIPluginTool, BaseGraphQLTool <name> # Examples: BraveSearch, HumanInputRun. Please use callbacks instead. Create a new model by parsing and validating input data from keyword arguments. May 2, 2023 · Tools that inherit from the BaseTool class and accept a single string argument will still be treated as string tools. BaseModel. It implements the RunnableSerializable interface, making tools composable with other LangChain components through the Runnable protocol. v1 BaseTool # class langchain_core. lipqaxwlcjthyrpqyumzzzyagfaycnwonaarwrhqwlvcfbxlketpgfzpsx