useToolData

Tool data hook from moonpeak.

import { useToolData } from "moonpeak";

useToolData<In, Out>(): ToolData<In, Out>

Everything about the tool call this View was opened for: the input, your handler's structured output, the raw result and its state.

Returns

Field	Type	Meaning
`input`	`In	undefined`
`output`	`Out	undefined`
`content`	`ContentBlock[]	undefined`
`isPending`	`boolean`	No result yet and not cancelled. Show a skeleton.
`isStreaming`	`boolean`	The host is still streaming the input.
`isError`	`boolean`	The tool returned `isError: true` (your handler threw).
`isCancelled`	`boolean`	The user or host cancelled the call.
`tool`	`{ name, title?, description? }`	Which tool this View belongs to.
`result`	`CallToolResult	undefined`

Example

import { useToolData } from "moonpeak";

export default function Moon() {
  const { output, isPending, isError, content } = useToolData<{ date?: string }, { phase: string }>();
  if (isError) return <p>{content?.[0]?.text}</p>;
  if (isPending) return <p>Reading the sky…</p>;
  return <h1>{output?.phase}</h1>;
}

Notes

Handle isError and isPending before reading output.
Call every hook before the first early return.

Works in

Every MCP Apps host: ChatGPT, Claude, VS Code, Goose and the moonpeak inspector.

See all hooks in Runtime APIs.