telegraf.js - v4.11.2

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telegraf.js

Modern Telegram Bot API framework for Node.js

Bot API Version install size GitHub top language English chat

For 3.x users

Introduction

Bots are special Telegram accounts designed to handle messages automatically. Users can interact with bots by sending them command messages in private or group chats. These accounts serve as an interface for code running somewhere on your server.

Telegraf is a library that makes it simple for you to develop your own Telegram bots using JavaScript or TypeScript.

Features

Example

const { Telegraf } = require('telegraf');

const bot = new Telegraf(process.env.BOT_TOKEN);
bot.start((ctx) => ctx.reply('Welcome'));
bot.help((ctx) => ctx.reply('Send me a sticker'));
bot.on('sticker', (ctx) => ctx.reply('👍'));
bot.hears('hi', (ctx) => ctx.reply('Hey there'));
bot.launch();

// Enable graceful stop
process.once('SIGINT', () => bot.stop('SIGINT'));
process.once('SIGTERM', () => bot.stop('SIGTERM'));
const { Telegraf } = require('telegraf');

const bot = new Telegraf(process.env.BOT_TOKEN);
bot.command('oldschool', (ctx) => ctx.reply('Hello'));
bot.command('hipster', Telegraf.reply('λ'));
bot.launch();

// Enable graceful stop
process.once('SIGINT', () => bot.stop('SIGINT'));
process.once('SIGTERM', () => bot.stop('SIGTERM'));

For additional bot examples see the new docs repo.

Resources

Getting started

Telegram token

To use the Telegram Bot API, you first have to get a bot account by chatting with BotFather.

BotFather will give you a token, something like 123456789:AbCdefGhIJKlmNoPQRsTUVwxyZ.

Installation

$ npm install telegraf

or

$ yarn add telegraf

or

$ pnpm add telegraf

Telegraf class

Telegraf instance represents your bot. It's responsible for obtaining updates and passing them to your handlers.

Start by listening to commands and launching your bot.

Context class

ctx you can see in every example is a Context instance. Telegraf creates one for each incoming update and passes it to your middleware. It contains the update, botInfo, and telegram for making arbitrary Bot API requests, as well as shorthand methods and getters.

This is probably the class you'll be using the most.

Shorthand methods

import { Telegraf } from 'telegraf';

const bot = new Telegraf(process.env.BOT_TOKEN);

bot.command('quit', async (ctx) => {
// Explicit usage
await ctx.telegram.leaveChat(ctx.message.chat.id);

// Using context shortcut
await ctx.leaveChat();
});

bot.on('text', async (ctx) => {
// Explicit usage
await ctx.telegram.sendMessage(ctx.message.chat.id, `Hello ${ctx.state.role}`);

// Using context shortcut
await ctx.reply(`Hello ${ctx.state.role}`);
});

bot.on('callback_query', async (ctx) => {
// Explicit usage
await ctx.telegram.answerCbQuery(ctx.callbackQuery.id);

// Using context shortcut
await ctx.answerCbQuery();
});

bot.on('inline_query', async (ctx) => {
const result = [];
// Explicit usage
await ctx.telegram.answerInlineQuery(ctx.inlineQuery.id, result);

// Using context shortcut
await ctx.answerInlineQuery(result);
});

bot.launch();

// Enable graceful stop
process.once('SIGINT', () => bot.stop('SIGINT'));
process.once('SIGTERM', () => bot.stop('SIGTERM'));

Production

Webhooks

import { Telegraf } from "telegraf";

const bot = new Telegraf(token);

bot.on("text", ctx => ctx.reply("Hello"));

// Start webhook via launch method (preferred)
bot.launch({
webhook: {
// Public domain for webhook; e.g.: example.com
domain: webhookDomain,

// Port to listen on; e.g.: 8080
port: port,

// Optional path to listen for.
// `bot.secretPathComponent()` will be used by default
hookPath: webhookPath,

// Optional secret to be sent back in a header for security.
// e.g.: `crypto.randomBytes(64).toString("hex")`
secretToken: randomAlphaNumericString,
},
});

Use createWebhook() if you want to attach Telegraf to an existing http server.

const { createServer } from "http";

createServer(await bot.createWebhook({ domain: "example.com" })).listen(3000);
const { createServer } from "https";

createServer(tlsOptions, await bot.createWebhook({ domain: "example.com" })).listen(8443);

Error handling

If middleware throws an error or times out, Telegraf calls bot.handleError. If it rethrows, update source closes, and then the error is printed to console and process hopefully terminates. If it does not rethrow, the error is swallowed.

Default bot.handleError always rethrows. You can overwrite it using bot.catch if you need to.

⚠️ Always rethrow TimeoutError!

⚠️ Swallowing unknown errors might leave the process in invalid state!

ℹ️ In production, systemd or pm2 can restart your bot if it exits for any reason.

Advanced topics

Working with files

Supported file sources:

  • Existing file_id
  • File path
  • Url
  • Buffer
  • ReadStream

Also, you can provide an optional name of a file as filename when you send the file.

bot.on('message', async (ctx) => {
// resend existing file by file_id
await ctx.replyWithSticker('123123jkbhj6b');

// send file
await ctx.replyWithVideo({ source: '/path/to/video.mp4' });

// send stream
await ctx.replyWithVideo({
source: fs.createReadStream('/path/to/video.mp4')
});

// send buffer
await ctx.replyWithVoice({
source: Buffer.alloc()
});

// send url via Telegram server
await ctx.replyWithPhoto('https://picsum.photos/200/300/');

// pipe url content
await ctx.replyWithPhoto({
url: 'https://picsum.photos/200/300/?random',
filename: 'kitten.jpg'
});
})

Middleware

In addition to ctx: Context, each middleware receives next: () => Promise<void>.

As in Koa and some other middleware-based libraries, await next() will call next middleware and wait for it to finish:

import { Telegraf } from 'telegraf';

const bot = new Telegraf(process.env.BOT_TOKEN);

bot.use(async (ctx, next) => {
console.time(`Processing update ${ctx.update.update_id}`);
await next() // runs next middleware
// runs after next middleware finishes
console.timeEnd(`Processing update ${ctx.update.update_id}`);
})

bot.on('text', (ctx) => ctx.reply('Hello World'));
bot.launch();

// Enable graceful stop
process.once('SIGINT', () => bot.stop('SIGINT'));
process.once('SIGTERM', () => bot.stop('SIGTERM'));

With this simple ability, you can:

Usage with TypeScript

Telegraf is written in TypeScript and therefore ships with declaration files for the entire library. Moreover, it includes types for the complete Telegram API via the typegram package. While most types of Telegraf's API surface are self-explanatory, there's some notable things to keep in mind.

Extending Context

The exact shape of ctx can vary based on the installed middleware. Some custom middleware might register properties on the context object that Telegraf is not aware of. Consequently, you can change the type of ctx to fit your needs in order for you to have proper TypeScript types for your data. This is done through Generics:

import { Context, Telegraf } from 'telegraf';

// Define your own context type
interface MyContext extends Context {
myProp?: string
myOtherProp?: number
}

// Create your bot and tell it about your context type
const bot = new Telegraf<MyContext>('SECRET TOKEN');

// Register middleware and launch your bot as usual
bot.use((ctx, next) => {
// Yay, `myProp` is now available here as `string | undefined`!
ctx.myProp = ctx.chat?.first_name?.toUpperCase();
return next();
});
// ...

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