Tool<Input extends Object, Options extends ToolOptions, Output extends Object> class abstract base

A LangChain tool.

The Input to the tool needs to be described by the inputJsonSchema.

You can easily create a tool from a function using Tool.fromFunction.

If you want to create a tool that accepts a single string input and returns a string output, you can use StringTool or StringTool.fromFunction.

Inheritance

Object
Runnable<Input, Options, Output>
BaseLangChain<Input, Options, Output>
Tool

Implemented types

ToolSpec

Implementers

StringTool

Constructors

Tool({required String name, required String description, required Map<String, dynamic> inputJsonSchema, bool strict = false, bool returnDirect = false, Output handleToolError(ToolException)?, Options? defaultOptions}): A LangChain tool.

Properties

defaultOptions → Options: The default options to use when invoking the Runnable.
finalinherited
description → String: Used to tell the model how/when/why to use the tool. You can provide few-shot examples as a part of the description.
final
handleToolError → Output Function(ToolException)?: Handle the content of the ToolException thrown by the tool.
final
hashCode → int: The hash code for this object.
no setteroverride
inputJsonSchema → Map<String, dynamic>: Schema to parse and validate tool's input arguments. Following the JSON Schema specification.
final
name → String: The unique name of the tool that clearly communicates its purpose.
final
returnDirect → bool: Whether to return the tool's output directly. Setting this to true means that after the tool is called, the AgentExecutor will stop looping.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
strict → bool: Whether to enable strict schema adherence when generating the tool call. If set to true, the model will follow the exact schema defined in the inputJsonSchema field.
final

Methods

batch(List<Input> inputs, {List<Options>? options}) → Future<List<Output>>: Batches the invocation of the Runnable on the given inputs.
inherited
bind(Options options) → RunnableBinding<Input, Options, Output>: Binds the Runnable to the given options.
inherited
close() → void: Cleans up any resources associated with it the Runnable.
inherited
getCompatibleOptions(RunnableOptions? options) → Options?: Returns the given options if they are compatible with the Runnable, otherwise returns null.
inherited
getInputFromJson(Map<String, dynamic> json) → Input: Parses the input JSON to the tool's input type.
invoke(Input input, {Options? options}) → Future<Output>: Runs the tool.
override
invokeInternal(Input input, {Options? options}) → Future<Output>: Actual implementation of invoke method logic.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
pipe<NewRunOutput extends Object?, NewCallOptions extends RunnableOptions>(Runnable<Output, NewCallOptions, NewRunOutput> next) → RunnableSequence<Input, NewRunOutput>: Pipes the output of this Runnable into another Runnable using a RunnableSequence.
inherited
stream(Input input, {Options? options}) → Stream<Output>: Streams the output of invoking the Runnable on the given input.
inherited
streamFromInputStream(Stream<Input> inputStream, {Options? options}) → Stream<Output>: Streams the tool's output for the input resulting from reducing the input stream.
override
toJson() → Map<String, dynamic>: Converts the tool spec to a JSON-serializable map.
override
toString() → String: A string representation of this object.
inherited
withFallbacks(List<Runnable<Input, RunnableOptions, Output>> fallbacks) → RunnableWithFallback<Input, Output>: Adds fallback runnables to be invoked if the primary runnable fails.
inherited
withRetry({int maxRetries = 3, FutureOr<bool> retryIf(Object e)?, List<Duration?>? delayDurations, bool addJitter = false}) → RunnableRetry<Input, Output>: Adds retry logic to an existing runnable.
inherited

Operators

operator ==(covariant ToolSpec other) → bool: The equality operator.
override

Static Methods

fromFunction<Input extends Object, Output extends Object>({required String name, required String description, required Map<String, dynamic> inputJsonSchema, bool strict = false, required FutureOr<Output> func(Input input), Input getInputFromJson(Map<String, dynamic> json)?, bool returnDirect = false, Output handleToolError(ToolException)?}) → Tool<Object, ToolOptions, Object>: Creates a Tool from a function.
override