InvokableTool

Extended tool interface that supports direct invocation with type-safe input and output. This interface is useful for testing and standalone tool execution.

Extends

Tool

Type Parameters

| Type Parameter | Description | | -------------- | ------------------------------------ | | TInput | Type for the tool’s input parameters | | TReturn | Type for the tool’s return value |

Properties

name

abstract name: string;

Defined in: src/tools/tool.ts:109

The unique name of the tool. This MUST match the name in the toolSpec.

Inherited from

Tool.name

description

abstract description: string;

Defined in: src/tools/tool.ts:116

Human-readable description of what the tool does. This helps the model understand when to use the tool.

This MUST match the description in the toolSpec.description.

Inherited from

Tool.description

toolSpec

abstract toolSpec: ToolSpec;

Defined in: src/tools/tool.ts:121

OpenAPI JSON specification for the tool. Defines the tool’s name, description, and input schema.

Inherited from

Tool.toolSpec

Methods

stream()

abstract stream(toolContext): ToolStreamGenerator;

Defined in: src/tools/tool.ts:156

Executes the tool with streaming support. Yields zero or more ToolStreamEvents during execution, then returns exactly one ToolResultBlock as the final value.

Parameters

| Parameter | Type | Description | | ------------- | -------------------------------- | ----------------------------------------------------------------------- | | toolContext | ToolContext | Context information including the tool use request and invocation state |

Returns

ToolStreamGenerator

Async generator that yields ToolStreamEvents and returns a ToolResultBlock

Example

const context = {
  toolUse: {
    name: 'calculator',
    toolUseId: 'calc-123',
    input: { operation: 'add', a: 5, b: 3 }
  },
}

// The return value is only accessible via explicit .next() calls
const generator = tool.stream(context)
for await (const event of generator) {
  // Only yields are captured here
  console.log('Progress:', event.data)
}
// Or manually handle the return value:
let result = await generator.next()
while (!result.done) {
  console.log('Progress:', result.value.data)
  result = await generator.next()
}
console.log('Final result:', result.value.status)

Inherited from

Tool.stream

invoke()

invoke(input, context?): Promise<TReturn>;

Defined in: src/tools/tool.ts:179

Invokes the tool directly with type-safe input and returns the unwrapped result.

Unlike stream(), this method:

Returns the raw result (not wrapped in ToolResult)
Consumes async generators and returns only the final value
Lets errors throw naturally (not wrapped in error ToolResult)

Parameters

| Parameter | Type | Description | | ---------- | -------------------------------- | --------------------------------- | | input | TInput | The input parameters for the tool | | context? | ToolContext | Optional tool execution context |

Returns

Promise<TReturn>

The unwrapped result