{
  "method": "sessionUpdate",
  "args": [
    {
      "sessionId": "test-session-id",
      "update": {
        "sessionUpdate": "agent_thought_chunk",
        "content": {
          "type": "text",
          "text": "Model rerouted from gpt-5 to gpt-5-mini (highRiskCyberActivity).\n\n"
        }
      }
    }
  ]
}