grammY port of NestJS Telegraf

:information_source: This project would not be possible without the help and assistance of Aleksandr Bukhalo and the fantastic bukhalo/nestjs-telegraf project.

Table of Contents

• grammY port of NestJS Telegraf
  • Table of Contents
  • Features
  • Installation
  • Usage
  • grammY instance access
  • Asynchronous Configuration
  • Getting Updates
    • Long polling
    • Webhooks
  • Middlewares
  • Multiple Bots
  • Standalone Applications

NestJS grammY – powerful solution for creating Telegram bots.

This package uses the best of the NodeJS world under the hood. grammY is the most powerful library for creating bots and NestJS is a progressive framework for creating well-architectured applications. This module provides fast and easy way for creating Telegram bots and deep integration with your NestJS application.

Features

• Simple. Easy to use.
• Ton of decorators available out of the box for handling bot actions.
• Ability to create custom decorators.
• grammY plugins and custom plugins support.
• Ability to run multiple bots simultaneously.
• Full support of NestJS guards, interceptors, filters and pipes!

Installation

npm i @grammyjs/nestjs
# or
yarn add @grammyjs/nestjs

Usage

Once the installation process is complete, we can import the NestjsGrammyModule into the root AppModule:

import { Module } from '@nestjs/common'
import { NestjsGrammyModule } from '@grammyjs/nestjs'

@Module({
    imports: [
        NestjsGrammyModule.forRoot({
            token: 'TELEGRAM_BOT_TOKEN',
        }),
    ],
})
export class AppModule {}

Then create app.update.ts file and add some decorators for handling Telegram bot API updates:

import { Bot, Context } from 'grammy'
import { InjectBot, Update, Message, Start, Hears, Ctx, Help, Admin } from '@grammyjs/nestjs'

@Update()
@UseInterceptors(ResponseTimeInterceptor)
@UseFilters(GrammyExceptionFilter)
export class EchoUpdate {
    constructor(
        @InjectBot(EchoBotName)
        private readonly bot: Bot<Context>,
        private readonly echoService: EchoService,
    ) {
        log('echo update starting', this.bot ? this.bot.botInfo.id : '(booting)')
    }

    @Start()
    async onStart(@Ctx() ctx: Context): Promise<void> {
        // const me = await this.bot.api.getMe()
        log('onStart!!', this.bot ? this.bot.botInfo : '(booting)')
        ctx.reply(`Hey, I'm ${this.bot.botInfo.first_name}`)
    }

    @Help()
    async onHelp(@Ctx() ctx: Context): Promise<void> {
        ctx.reply('Send me any text')
    }

    @Admin()
    @UseGuards(AdminGuard)
    async onAdminCommand(@Ctx() ctx: Context): Promise<void> {
        ctx.reply('Welcome, Judge')
    }

    @Hears('greetings')
    async onMessage(@Ctx() ctx: Context, @Message('text', new ReverseTextPipe()) reversedText: string): Promise<void> {
        ctx.reply(reversedText)
    }

    @On('chat_member')
    @UpdateFilter(ctx => ctx.chatMember?.new_chat_member.status === 'member')
    greetNewMember(@Ctx() ctx: Context) {
        ctx.reply(`Welcome to our chat, ${ctx.chatMember.new_chat_member.user.first_name}!`)
    }

    @On('message')
    @ChatType('private')
    onPrivateMessage(@Ctx() ctx: Context) {
        ctx.reply('Hello! This is private chat. You can continue to tell me your secrets')
    }
}

grammY instance access

If you want to use grammY instance directly, you can use @InjectBot for that.

import { Injectable } from '@nestjs/common'
import { Bot, Context } from 'grammy'
import { InjectBot } from '@grammyjs/nestjs'

@Injectable()
export class EchoService {
  constructor(@InjectBot(EchoBotName) private readonly bot: Bot<Context>) {}
  ...
}

Asynchronous Configuration

When you need to pass module options asynchronously instead of statically, use the forRootAsync() method. As with most dynamic modules, Nest provides several techniques to deal with async configuration.

One technique is to use a factory function:

NestjsGrammyModule.forRootAsync({
    useFactory: () => ({
        token: 'TELEGRAM_BOT_TOKEN',
    }),
})

Like other factory providers, our factory function can be async and can inject dependencies through inject.

NestjsGrammyModule.forRootAsync({
    imports: [ConfigModule.forFeature(grammyModuleConfig)],
    useFactory: async (configService: ConfigService) => ({
        token: configService.get<string>('TELEGRAM_BOT_TOKEN'),
    }),
    inject: [ConfigService],
})

Alternatively, you can configure the NestjsGrammyModule using a class instead of a factory, as shown below:

NestjsGrammyModule.forRootAsync({
    useClass: MyConfigService,
})

The construction above instantiates MyConfigService inside NestjsGrammyModule, using it to create the required options object. Note that in this example, the MyConfigService has to implement the MyOptionsFactory interface, as shown below. The NestjsGrammyModule will call the createMyOptions() method on the instantiated object of the supplied class.

@Injectable()
class MyConfigService implements MyOptionsFactory {
    createMyOptions(): NestjsGrammyModuleOptions {
        return {
            token: 'TELEGRAM_BOT_TOKEN',
        }
    }
}

If you want to reuse an existing options provider instead of creating a private copy inside the NestjsGrammyModule, use the useExisting syntax.

NestjsGrammyModule.forRootAsync({
    imports: [ConfigModule.forFeature(grammyModuleConfig)],
    useExisting: ConfigService,
})

Getting Updates

Long polling

By default, the bot receives updates using long-polling and requires no additional action.

Webhooks

To utilize webhooks, the best documentation is to review the Sample Firebase Bot package and how it configures webhooks.

At a high level, you simply enable webhooks and pass the webhook module as follows:

      useWebhook: true,
      include: [FirebaseWebhookModule],

This module must initialize the webhooks for grammY as such:

  configure(consumer: MiddlewareConsumer) {
    consumer.apply(webhookCallback(this.bot, 'express')).forRoutes('*')
  }

The last step is to write the update functions in a module like this:

@Update()
@UseInterceptors(ResponseTimeInterceptor)
@UseFilters(GrammyExceptionFilter)
export class WebhookUpdater {
  private readonly inlineKeyboard: InlineKeyboard

  constructor(
    @InjectBot(FirebaseBotName)
    private readonly bot: Bot<Context>,
    private readonly botService: FirebaseBotService,
  ) {
    log(`Initializing`, bot.isInited() ? bot.botInfo.first_name : '(pending)')
  }

  @Start()
  async onStart(@Ctx() ctx: Context): Promise<any> {
    log('onStart!!', this.bot ? this.bot.botInfo.first_name : '(booting)')
    return ctx.reply('Curious? Click me!', { reply_markup: this.inlineKeyboard })
  }

  @CallbackQuery('click-payload')
  async onCallback(@Ctx() ctx: Context): Promise<any> {
    return ctx.answerCallbackQuery({
      text: 'You were curious, indeed!',
    })
  }

  ...

Middlewares

@grammyjs/nestjs has support of the grammY middleware packages. To use an existing middleware package, simply import it and add it to the middlewares array:

NestjsGrammyModule.forRoot({
  middlewares: [session()],
}),

Multiple Bots

In some cases, you may need to run multiple bots at the same time. This can also be achieved with this module. To work with multiple bots, first create the bots. In this case, bot naming becomes mandatory.

import { Module } from '@nestjs/common'
import { ConfigModule } from '@nestjs/config'
import { NestjsGrammyModule } from '@grammyjs/nestjs'

@Module({
    imports: [
        ConfigModule.forRoot(),
        NestjsGrammyModule.forRootAsync({
            imports: [ConfigModule],
            botName: 'cat',
            useFactory: (configService: ConfigService) => ({
                token: configService.get<string>('CAT_BOT_TOKEN'),
            }),
            inject: [ConfigService],
        }),
        NestjsGrammyModule.forRootAsync({
            imports: [ConfigModule.forFeature(myModuleConfig)],
            botName: 'dog',
            useFactory: async (configService: ConfigService) => ({
                token: configService.get<string>('DOG_BOT_TOKEN'),
            }),
            inject: [ConfigService],
        }),
    ],
})
export class AppModule {}

:::caution Please note that you shouldn't have multiple bots without a name, or with the same name, otherwise they will get overridden. :::

You can also inject the Bot for a given bot:

import { Injectable } from '@nestjs/common'
import { InjectBot, Bot, Context } from '@grammyjs/nestjs'

@Injectable()
export class EchoService {
    constructor(@InjectBot('cat') private catBot: Bot<Context>) {}
}

To inject a given Bot to a custom provider (for example, factory provider), use the getBotToken() function passing the name of the bot as an argument.

{
  provide: CatsService,
  useFactory: (catBot: Bot<Context>) => {
    return new CatsService(catBot);
  },
  inject: [getBotToken('cat')],
}

Another useful feature of the @grammyjs/nestjs module is the ability to choose which modules should handle updates for each launched bot. By default, module searches for handlers throughout the whole app. To limit this scan to only a subset of modules, use the include property.

NestjsGrammyModule.forRootAsync({
  imports: [ConfigModule],
  botName: 'cat',
  useFactory: (configService: ConfigService) => ({
    token: configService.get<string>('CAT_BOT_TOKEN'),
    include: [CatsModule],
  }),
  inject: [ConfigService],
}),

Standalone Applications

If you initialized your application with the Nest CLI, Express framework will be installed by default along with Nest. Nest and NestJS grammY does not require Express for work. So if you don't plan to getting bot updates through webhooks, and you don't need a web server, you can remove Express.

To do this, change the bootstrap function in the main.ts file of your project on something like that:

async function bootstrap() {
    const app = await NestFactory.createApplicationContext(AppModule)
}
bootstrap()

This initializes Nest as a standalone application (without any network listeners).

All that remains is to remove unused dependencies:

npm un @nestjs/platform-express @types/express

:::info More information about standalone applications located at Nest documentation :::