{
  "message": "Message sent successfully",
  "userMessage": {
    "id": "msg_aBcD...",
    "chatId": "chat_aBcD...",
    "sender": "user",
    "content": "Can you suggest steps to resolve the TIN issue?",
    "timestampAt": "2026-06-27T10:05:00Z",
    "groundingSources": null
  },
  "aiMessage": {
    "id": "msg_eFgH...",
    "chatId": "chat_aBcD...",
    "sender": "ai",
    "content": "Here are the recommended steps to resolve the TIN deactivation:\n\n1. Contact FIRS directly...",
    "timestampAt": "2026-06-27T10:05:02Z",
    "groundingSources": {
      "groundingChunks": [
        { "web": { "uri": "https://firs.gov.ng/...", "title": "FIRS" } }
      ]
    }
  }
}