Lib for multi language support


It is important to understand:

  • Any bot can be translated

  • The bot consists of commands in which there are no untranslated places.

  • All commands are multilingual

  • There are no commands like /menuEn, /menuFr, /menuRu. There is only one /menu command

  • All multilingual texts must be placed in each language files (command), for example, in lng-en, lng-ru. This will make them easier to translate.

  • everything can be translated: any text, answer, keyboard, inline keyboard, alert...

This is especially important for large bots

Getting started

First - need to setup languages. For example with /setup command:

const enLang = {
    user: { whatIsYourName: "What is your name?" },
    hello: "Hello!",
    onlyOnEnglish: "Only on english"
    keyboards: {
        mainMenu: { buttons: "Bonus, Friends", text: "menu" }
        bonusMenu: { buttons: "Get bonus, Back", text: "Get your bonus now" }

const ruLang = {
    user: { whatIsYourName: "Как тебя зовут?" },
    hello: "Привет!",
    // not translated yet:
    // onlyOnEnglish: "Only on english"
    keyboards: {
        mainMenu: { buttons: "Бонус, Друзья", text: "меню"}
        bonusMenu: { buttons: "Получить бонус, Назад", text: "получи бонус"}

// first language is default language
Libs.Lang.setup("en", enLang);  // english is default now
Libs.Lang.setup("ru", ruLang);

Now default language is "english".

You can use lib now (for example, in command /test):

const lang = Libs.Lang;
// send messages on default language
Bot.sendMessage(lang.t("hello"))   // Hello!
Bot.sendMessage(lang.t("user.whatIsYourName"))  // What is your name?

Bot.sendMessage(lang.t("onlyOnEnglish")) // "Only on english"
// Default language text always is used
//  for non translated keys yet

// send keyboard for Main menu:

// or send Bonus menu:

How to use

Change user lang


You can get user language code. For example in /start:

// in /start command
let lang_code = request.from.language_code;

Get cur lang

let lang = Libs.Lang.user.getLang()

Change default lang

let default = Libs.Lang.default.getCurLang()

Tips. Also you can use multi lang command. This is not recommended but sometimes a good solution

In BJS for command /hello:

Bot.runCommand("/hello_" + Libs.Lang.user.getLang())

Also you can use

Libs.Lang.t("translation-key", "ru")

for non user actions: in webhooks and etc

Get translation by language code

Sometimes we do not have user object. For example, on income webhooks or with Bot.runAll command and etc. Therefore, we cannot determine the current language.

The following code might be helpful in such cases.

// command /test
// you can pass language code in params
let lng = params;
// or in options with "/test", options: {lngCode: "fr"} )
let lng = options.lngCode

// So now:
// lng = "fr"

    Libs.Lang.t("hello", lng)
)   // Привет!

Get all language json

// get all json for default language:

// get all json for "ru":

Using aliases

You can set aliases for language.

For /setup

const enLang = {
    aliases: {
       // Command /start have aliases:
       //       home, dashboard and /main:
       "home, dashboard, /main": "/start",
       // command /otherCommand have aliases:
       //       alias1, alias2
       "alias1,alias2": "/otherCommand"
    user: { whatIsYourName: "What is your name?" },

Libs.Lang.setup("en", enLang);

For Master command * :

// find multilanguage aliases
let cmd = Libs.Lang.getCommandByAlias(message);
if(cmd){{ command: cmd }) }

// also it is possible define language
// let cmd = Libs.Lang.getCommandByAlias(message, "ru");
// if(cmd){{ command: cmd }) }

Good practices

Use different language files (command) for each language.

For example "lng-en.js", "lng-fr.js" and etc. So it's easier to translate.

In /setup you can make something like this:

let languages = ["en", "es", "cn", "ru"];
let cmdName;

for(let i in languages){
    cmdName = "lng-" + languages[i].code;{ command: cmdName })

Bot.sendMessage("Multi Languages - installed");

Make a simple command based structure

const enLang = {
    command1: {
      text: "your text",
      // keys
    command2: {
      text: "your text"
      // keys,
    // bot menus
    menus: {
      mainMenu: {
      helpMenu: {
    // common links
    links: {
      homePage: "<a href=''>Home page</a>",
    alert: {
      error: "sorry, we have error"

Libs.Lang.setup("en", enLang);

Make translation for text and keyboard:

const enLang = {
    command1: {
       text: "Please confirm",
       keyboard: "Yes, Cancel",
       // you can also attach Inline keyboard:
       inlineKeyboard: {
         buttons: [ 
           {title: "google", url: "" },
           {title: "other command", command: "/othercommand"}
          text: "Please make a choice."

Libs.Lang.setup("en", enLang);

So in /command1 you can make:


// send inline keyboard:

Use aliases translations

See this

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