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JavaScript@langchain/coretoolstool
Functionā—Since v0.3

tool

Creates a new StructuredTool instance with the provided function, name, description, and schema.

Schema can be provided as Zod or JSON schema, and both will be validated.

Copy
tool<
  SchemaT extends ZodStringV3,
  ToolOutputT = any,
  FuncT extends RunnableFunc<InferInteropZodOutput<SchemaT>, ToolOutputT, ToolRunnableConfig> = RunnableFunc<InferInteropZodOutput<SchemaT>, ToolOutputT, ToolRunnableConfig>
>(
  func: FuncT,
  fields: ToolWrapperParams<SchemaT>
): DynamicTool<InferToolOutputFromFunc<FuncT>, InferToolEventFromFunc<FuncT>>

Used in Docs

  • Agent Client Protocol (ACP)
  • Agents
  • Build a custom SQL agent
  • Build a multi-source knowledge base with routing
  • Build a personal assistant with subagents
(36 more not shown)

Parameters

NameTypeDescription
func*FuncT

The function to invoke when the tool is called.

fields*ToolWrapperParams<SchemaT>

An object containing the following properties:

View source on GitHub