curl --request GET \
  --url https://api.portkey.ai/v1/responses/{response_id}/input_items \
  --header 'x-portkey-api-key: <api-key>'

{
  "object": "list",
  "data": [
    {
      "type": "message",
      "role": "user",
      "status": "in_progress",
      "content": [
        {
          "type": "input_text",
          "text": "<string>"
        }
      ],
      "id": "<string>"
    }
  ],
  "has_more": true,
  "first_id": "<string>",
  "last_id": "<string>"
}