first_packet

{
  event: "message",
  data: {
    visitorNumber: 1,
    widgetPublicId: "fa38df51-e81c-4bda-9284-831331f6352b",
    widgetName: "Eduardo Moroni's 1st widget",
    agentTransferRestricted: false,
    knowledgebaseAvailable: true,
    visitorTypingMessageEnabled: true,
    visitorFileExchangeEnabled: true,
    visitorFileExchangeSettings:
      '{"visitorChatEnabled":true,"visitorFileUploadEnabled":true,"agentFileUploadEnabled":true,"fileTypeRestrictionEnabled":true,"fileTypes":[],"fileTypeRestriction":"executable"}',
    secureDataExchangeEnabled: true,
    secureDataExchangeSettings:
      '{"cc":false, "ccWithZip":true, "ssn":true, "secureNote":true}',
    cobrowsingEnabled: false,
    createdDate: 1559899543927,
    casePublicId: "3df1005b-20d0-4105-8fca-f308f993d705",
    status: 3,
    agentId: "eduardo.moroni@snapengage.com",
    agentAlias: "Eduardo Moroni",
    agentPhone: "",
    agentAvatar: "",
    pageTitle: "playground.ajaxtown.com",
    descriptionText: "Olá",
    translatedDescriptionText: "Hello",
    widgetLanguage: "es",
    autoTranslate: {
      enabled: true, // REQUIRED
      selectedLanguage: "pt", // OPTIONAL
    },
    language: "en-US,en;q=0.9,pt;q=0.8",
    decodedLanguages: ["English", "English", "Portuguese"],
    formattedGeoLocation: "Berlin, Germany",
    geoCity: "Berlin",
    geoRegionCode: "BE",
    geoCountryName: "Germany",
    geoCountryCode: "DE",
    geoLatitude: "52.520007",
    geoLongitude: "13.404954",
    geoIsp: "",
    geoOrganization: "M247 Europe",
    ipAddress: "152.89.163.172",
    locale: "en",
    timezone: "Europe/Berlin",
    agent:
      "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3806.1 Safari/537.36",
    browser: ["Chrome", "Chrome", "Chrome (76.0.3806.1)"],
    os: ["Mac", "OS X", "Apple OS X 10.14.3"],
    userVisitCount: 46,
    userCommunicationsCount: 5,
    userLastContacts: [
      "6baf5567-e3e0-4093-8ca6-415b4ec13762,1559894012758",
      "759b2b3a-fa57-40ab-84ab-53e952009a58,1559893852488",
      "0a987c63-4673-460c-bbf1-15e1c5724e5c,1559733312949",
      "42cbe20c-54c4-47e1-a0d8-40f6461db526,1559730541562",
      "4bdf3cbc-191b-441f-9c98-ed32188e382e,1559728787924"
    ],
    visitorTranscriptTracked: true,
    fromUrl: "http://playground.ajaxtown.com/eduardo.html",
    entryPageUrl: "http://playground.ajaxtown.com/eduardo.html",
    entryPageReferrer: "",
    decodedSearchData: ["", ""],
    variables: "",
    variablesJS: "",
    transfer: false,
    reconnect: false,
    widgetSwitch: false,
    email: "eduardomoroni@gmail.com",
    proactiveMessage: "",
    agentIntroMsgAlertType: 0,
    transcriptMessages: [],
    chatDuration: 0,
    channelType: "POLL",
    channel: "POLL",
    type: "chat"
  },
  channel:
    "private-snapabug-hr-staging-ZWR1YXJkby5tb3JvbmlAc25hcGVuZ2FnZS5jb20="
};

In this first package, we'll need to receive the ID of this descriptionMessage so we'll be able to update it with the translation.
We will also need two additional fields to detect if the widget has auto-translate enabled and the default language. Which will be the language in which we are translating the visitor messages.