{
  "request": {
    "type": "control_request",
    "request_id": "req-hook-1",
    "request": {
      "subtype": "hook_callback",
      "callback_id": "cowork-task-bg-block",
      "input": {
        "tool_input": {
          "run_in_background": true
        }
      },
      "tool_use_id": "toolu_01SyntheticTask"
    }
  },
  "response": {
    "type": "control_response",
    "response": {
      "subtype": "success",
      "request_id": "req-hook-1",
      "response": {
        "decision": "block",
        "reason": "Background agents disabled"
      }
    }
  }
}