{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/Message",
  "title": "Message",
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "description": "Unique ID of the message."
    },
    "message_type": {
      "type": "string",
      "description": "Type of message (normal, private, system).",
      "enum": [
        "normal",
        "private",
        "system"
      ]
    },
    "actor_type": {
      "type": "string",
      "description": "Type of actor who sent the message (user, agent, system).",
      "enum": [
        "user",
        "agent",
        "system"
      ]
    },
    "actor_id": {
      "type": "string",
      "description": "ID of the actor."
    },
    "message_parts": {
      "type": "array",
      "description": "Parts that compose the message content.",
      "items": {
        "type": "object",
        "properties": {
          "text": {
            "type": "object",
            "properties": {
              "content": {
                "type": "string",
                "description": "Text content of the message part."
              }
            }
          },
          "image": {
            "type": "object",
            "properties": {
              "url": {
                "type": "string",
                "format": "uri",
                "description": "URL of the image."
              }
            }
          }
        }
      }
    },
    "reply_parts": {
      "type": "array",
      "description": "Response enablers for agent or bot messages allowing quick replies.",
      "items": {
        "type": "object"
      }
    },
    "created_time": {
      "type": "string",
      "format": "date-time",
      "description": "Timestamp when the message was created."
    }
  }
}