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sunpeak API

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Overview

Returns a function to download files through the host. Since MCP Apps run in sandboxed iframes where direct downloads are blocked, this provides a host-mediated mechanism for file exports. Supports embedded text content, embedded binary (base64) content, and resource links that the host fetches on behalf of the app. See the MCP Apps downloadFile request for protocol details.

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Import

import { useDownloadFile } from 'sunpeak';

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Signature

function useDownloadFile(): (params: DownloadFileParams) => Promise<DownloadFileResult | undefined>

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DownloadFileParams

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contents
(EmbeddedResource | ResourceLink)[]
required
Resource contents to download — embedded (inline data) or linked (host fetches).

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Returns

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downloadFile
(params: DownloadFileParams) => Promise<DownloadFileResult | undefined>
Function to request a file download through the host.

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DownloadFileResult

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isError
boolean
Whether the download failed (e.g. user cancelled or host denied).

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Usage

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Embedded text content

import { useDownloadFile } from 'sunpeak';

function ExportButton({ data }: { data: unknown }) {
  const downloadFile = useDownloadFile();

  return (
    <button onClick={() => downloadFile({
      contents: [{
        type: 'resource',
        resource: {
          uri: 'file:///export.json',
          mimeType: 'application/json',
          text: JSON.stringify(data, null, 2),
        },
      }],
    })}>
      Export JSON
    </button>
  );
}

const downloadFile = useDownloadFile();

await downloadFile({
  contents: [{
    type: 'resource_link',
    uri: 'https://api.example.com/reports/q4.pdf',
    name: 'Q4 Report',
    mimeType: 'application/pdf',
  }],
});