# Cloudflare Workers Telegram Bot

> A tour of the rewritten cf-workers-telegram-bot API for running a Telegram bot on Cloudflare Workers.

- URL: https://seanbehan.ca/posts/cf-workers-telegram-bot
- Author: Sean Behan
- Published: May 15, 2024
- Tags: cloudflare, typescript
- Reading time: 2 minutes

---

This past week I spent rewriting

[`cf-workers-telegram-bot`](https://github.com/codebam/cf-workers-telegram-bot).

Here I'm going to show you the newly updated API that anyone can use to run a

Telegram Bot on Cloudflare Workers or any other serverless platform.

### Project Setup

First you need to set up a new Cloudflare Workers project using wrangler.

```shell
npm create cloudflare@latest
```

This will prompt you for a project name first. Choose a name for your new

project or use the default.

Next you'll be prompted for the type of application you want to deploy. You

should choose a "Hello World" Worker.

After that you'll be asked a few more questions, like if you want to use

TypeScript, and Git (optional, but recommended). You don't need to deploy just

yet.

### Adding Your Bot Token

Next you can add the token you get from `@BotFather` on Telegram as a secret so

you don't have to keep it in the code.

```shell
npx wrangler secret put TOKEN
```

Once you've created your project and created your secret you'll want to install

the `cf-workers-telegram-bot` library to start coding.

```shell
cd your-new-project
npm i @codebam/cf-workers-telegram-bot
```

This will give you access to my `TelegramBot` class for creating a Telegram Bot.

### Writing the Bot

To get started you can open `src/index.ts` in your favorite editor such as

vscode or vim. Then you can import like this.

```javascript
import TelegramBot, { TelegramExecutionContext } from '@codebam/cf-workers-telegram-bot';
```

Then you can simply write your bot like this.

```javascript
export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
    const bot = new TelegramBot(env.TOKEN);
    await bot.on('start', async function (context: TelegramExecutionContext) {
      switch (context.update_type) {
	case 'message':
	  await context.reply('Hello from Cloudflare workers');
	  break;

	default:
	  break;
      }
    }).handle(request.clone());
    return new Response('ok');
  },
};
```

### Deployment and Webhook

Now you're ready to deploy.

```shell
npx wrangler deploy
```

You can set your webhook by going to the URL you've been given plus your token and `?command=set`.

Like this. `https://telegram-bot.username.workers.dev/YOURTOKENHERE?command=set`

Now when you send your bot a message on Telegram it should respond with `Hello from Cloudflare workers`.

### Starter Template

If you've got this far and you don't want to code it all by yourself, you can

fork my repository [here](https://github.com/codebam/cwtb-consumer) to get

started with a working copy.