Function persistBinaryContent

src/utils/mcpOutputStorage.ts:148–174

(
  bytes: Buffer,
  mimeType: string | undefined,
  persistId: string,
)

 * for PDFs, pandas for xlsx, etc.).
 */
export async function persistBinaryContent(
  bytes: Buffer,
  mimeType: string | undefined,
  persistId: string,
): Promise<PersistBinaryResult> {
  await ensureToolResultsDir()
  const ext = extensionForMimeType(mimeType)
  const filepath = join(getToolResultsDir(), `${persistId}.${ext}`)

  try {
    await writeFile(filepath, bytes)
  } catch (error) {
    const err = toError(error)
    logError(err)
    return { error: err.message }
  }

  // mime type and extension are safe fixed-vocabulary strings (not paths/code)
  logEvent('tengu_binary_content_persisted', {
    mimeType: (mimeType ??
      'unknown') as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
    sizeBytes: bytes.length,
    ext: ext as AnalyticsMetadata_I_VERIFIED_THIS_IS_NOT_CODE_OR_FILEPATHS,
  })

  return { filepath, size: bytes.length, ext }
}

/**
 * Build a short message telling Claude where binary content was saved.