Kotlin Telegram Bot

Kotlin library for creating Telegram Bots. You can use clean version, with implementation for Spring, Ktor+Koin or create with you own implementation. It have also possibility to save state in database with Spring JPA or Exposed.

Full documentation with examples and explanations.

Example of applications in example-spring, example-ktor, example-core directories.

Why this library

• Focused on building a dialog with the user (for example, no need to specify chatId in dialog chains).
• Has many useful utilities (such as templating, keyboard and button creating and other).
• Telegram API methods realization have overloads for more comfortable usage (like a chatId as String or Long).
• Working on coroutines.
• Has clean version or with Spring or Ktor+Koin frameworks.
• Has possibility to save state in database with Spring JPA or Exposed.
• Easy to write tests for your bot.

⚠️ Limitations (will be resolved) ⚠️

• Now available only long polling (will be added webhook also).

Prerequisites

• JDK 17 or higher
• Kotlin 1.8 or higher
• Gradle or Maven

Quick start

build.gradle.kts

repositories {
    mavenCentral()
}
dependencies {
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-core:$telegram_bot_version")
}

Core version

Can be used for integrate with any frameworks manually.

com/example/myproject/App.kt

fun main(args: Array<String>): Unit {
    val config = TelegramBotConfig().apply {
        token = "<bot token required>"
        username = "<bot username required>"

        receiving {
            handling {
                startCommand()
            }
        }
    }
    val context = TelegramBotFactory.createTelegramBotContext(config)
    val updateReceiver = context.updateReceiver
    // get telegramBot, templater, buttonFactory and other from created context...

    // start and stop for example only, use this methods with starting and stopping your application
    updateReceiver.start()
    readlnOrNull()
    updateReceiver.stop()
}

com/example/myproject/handler/StartHandler.kt

fun BotHandling.startCommand() {
    command("/start", next = "get_name") {
        // you don't have to specify a chatId to send messages
        sendMessage("Hello, my name is ${bot.username} :-)")
        // but you can do it
        bot.sendMessage(chatId, "And what is your name?")
    }

    step("get_name") {
        sendMessage("Nice to meet you, $text!")
    }
}

Spring version

Ready-to-use solution for use with Spring.

build.gradle.kts

repositories {
    mavenCentral()
}
dependencies {
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-core:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-spring:$telegram_bot_version")
}

com/example/myproject/config/BotConfig.kt

@EnableTelegramBot
@Configuration
class BotConfig {

    @Bean //optional bean
    fun telegramBotConfig(): TelegramBotConfig = TelegramBotConfig().apply {
        //configure..
    }
}

resources/application.properties

telegram-bot.token=${TELEGRAM_BOT_TOKEN}
telegram-bot.username=${TELEGRAM_BOT_USERNAME}

com/example/myproject/handler/StartHandler.kt

@HandlerComponent
class StartHandler : BotHandler({
    command("/start") {
        sendMessage("Hello, my name is ${bot.username} :-)")
    }
})

Ktor+Koin version

Ready-to-use solution for use with Ktor+Koin.

build.gradle.kts

repositories {
    mavenCentral()
}
dependencies {
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-core:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-ktor:$telegram_bot_version")
}

com/example/myproject/KtorApp.kt

fun Application.module() {
    install(Koin) {
        modules(defaultModule)
    }
    install(TelegramBot) {
        //configure..
    }
}

resources/application.conf

telegram-bot {
    token = ${TELEGRAM_BOT_TOKEN}
    username = ${TELEGRAM_BOT_USERNAME}
}

com/example/myproject/handler/StartHandler.kt

@Factory
class StartHandler : BotHandler({
    command("/start") {
        sendMessage("Hello, my name is ${bot.username} :-)")
    }
})

Database integration

[!WARNING]
And it is highly recommended to use with saving states in database. There are ready-to-use solutions for Spring JPA and Exposed. Interfaces to be implemented with saving to the database described here.

Spring JPA

All you have to do is add a dependency for source-jpa:

Spring 3.x

dependencies {
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-core:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-spring:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-source-jpa:$telegram_bot_version")
}

Spring 2.7

dependencies {
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-core:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-spring:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-source-spring2-jpa:$telegram_bot_version")
}

Available properties

Exposed

To save the state in the database, it is necessary to connect to it using Exposed (example). Then add the dependency and specify the sources:

dependencies {
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-core:$telegram_bot_version")
    implementation("io.github.dehuckakpyt.telegrambot:telegram-bot-source-exposed:$telegram_bot_version")
}

val config = TelegramBotConfig().apply {
    messageSource = { MessageSource.inDatabase }
    receiving {
        callbackContentSource = {
            CallbackContentSource.inDatabase(
                maxCallbackContentsPerUser = 20
            )
        }
        chainSource = { ChainSource.inDatabase }
    }
}

🔗Full documentation with examples and explanations🔗.