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Overview

The useToolData hook provides reactive access to both the tool’s input arguments and output data (structured content). It replaces the need for separate input/output hooks. The output field contains the data from your MCP tool’s structuredContent response.

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Import

import { useToolData } from 'sunpeak';

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Signature

function useToolData<TInput, TOutput>(
  defaultInput?: TInput,
  defaultOutput?: TOutput
): ToolData<TInput, TOutput>

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Parameters

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defaultInput
TInput
Fallback value when no input is available. Optional.
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defaultOutput
TOutput
Fallback value when no output is available. Optional.

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Returns

Returns a ToolData<TInput, TOutput> object with the following fields:
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input
TInput | null
The tool call arguments.
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inputPartial
TInput | null
Streaming partial input during tool execution.
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output
TOutput | null
The structured content from the tool result.
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isError
boolean
Whether the tool result indicates an error.
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isLoading
boolean
Whether the tool is still executing.
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isCancelled
boolean
Whether the tool call was cancelled by the host or user.
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cancelReason
string | null
Optional reason for cancellation, or null if not cancelled.

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Usage

import { useToolData } from 'sunpeak';

interface ReviewInput {
  changesetId: string;
  title: string;
}

interface ReviewOutput {
  title: string;
  sections: Array<{ title: string; content: unknown[] }>;
}

function ReviewResource() {
  const { input, output, isLoading } = useToolData<ReviewInput, ReviewOutput>(
    undefined,
    { title: 'Review', sections: [] }
  );

  if (isLoading) return <div>Loading...</div>;

  return (
    <div>
      <h1>{output?.title}</h1>
      <p>Changeset: {input?.changesetId}</p>
    </div>
  );
}