{
  "chats": {
    "chatId1": {
      "chat_metadata": {
        "participants": {
          "userId1": true,
          "userId2": true,
          "userId3": true
        },
        "createdAt": "2025-10-16T22:46:00Z",
        "lastMessage": {
          "messageId": "messageId123",
          "senderId": "userId1",
          "content": "Último mensaje del chat",
          "timestamp": "2025-10-16T22:46:00Z"
        }
      },
      "messages": {
        "messageId123": {
          "senderId": "userId1",
          "content": "Hola, ¿cómo están?",
          "timestamp": "2025-10-16T22:45:00Z",
          "readBy": {
            "userId2": "2025-10-16T22:45:05Z",
            "userId3": null
          }
        },
        "messageId124": {
          "senderId": "userId2",
          "content": "Todo bien, gracias!",
          "timestamp": "2025-10-16T22:46:00Z",
          "readBy": {
            "userId1": "2025-10-16T22:46:05Z",
            "userId3": null
          }
        }
      }
    },
    "chatId2": {
      "chat_metadata": {
        "participants": {
          "userId4": true,
          "userId5": true
        },
        "createdAt": "2025-10-16T20:00:00Z",
        "lastMessage": {
          "messageId": "messageId125",
          "senderId": "userId4",
          "content": "Nos vemos mañana",
          "timestamp": "2025-10-16T20:10:00Z"
        }
      },
      "messages": {
        "messageId125": {
          "senderId": "userId4",
          "content": "Nos vemos mañana",
          "timestamp": "2025-10-16T20:10:00Z",
          "readBy": {
            "userId5": "2025-10-16T20:10:05Z"
          }
        }
      }
    }
  }
}