Payment Processing in a Telegram Bot Using Stars

In this guide, we will explore how to implement a payment system in a Telegram bot using Stars. We will use the code provided in the index.ts file, which already contains the main commands and message handlers.

1. Setting Up the Bot

First, make sure you have a Telegram bot created through BotFather. Obtain your bot's token and add it to your project.

2. Command Handling

The code already implements commands such as /start and /buy. The /buy command initiates the purchasing process, prompting the user to choose one of the available products:

bot.command('buy', async (ctx) => {
    await ctx.replyWithChatAction('typing')
    await ctx.reply("Choose the option", {
        reply_markup: {
            inline_keyboard: [
                [{text:"Buy me coffee", callback_data: "buy_coffee"}, {text:"Buy me a book", callback_data: "buy_book"}, {text:"Buy me a juice", callback_data: "buy_juice"}],
                [{text:"Buy me a course", callback_data: "buy_course"}],
            ]
        }
    })
})

3. Payment Processing

When the user selects a product, the bot processes the corresponding callback_query. Depending on the selected product, the bot sends the user an invoice for payment:

bot.on('callback_query:data', async (ctx) => {
    await ctx.replyWithChatAction("typing")
    const callbackData = ctx.callbackQuery.data
    if (callbackData.startsWith("buy")) {
        if (callbackData.endsWith("coffee")) {
            await ctx.replyWithInvoice(
                "Buy me a coffee",
                "Hot coffee",
                "Coffee",
                "",
                "XTR",
                [{ label: "Price", amount: 40 }]
            )
            return 
        }
        // Аналогично для других товаров...
    }
})

4. Pre-checkout Handling

The bot also handles pre-checkout to confirm that the user is ready to make a payment:

bot.on("pre_checkout_query", (ctx) => {
    ctx.answerPreCheckoutQuery(true);
    return;
});

5. Server Setup

At the end of the file, we set up the server to handle incoming requests:

Deno.serve(async (req) => {
    try {
    const url = new URL(req.url);
    if (url.searchParams.get('secret') !== Deno.env.get('FUNCTION_SECRET')) {
    return new Response('not allowed', { status: 405 });
    }
    return await handleUpdate(req);
    } catch (err) {
    console.error(err);
    }
});

Conclusion

Now you have a basic structure for implementing payments in a Telegram bot using Stars. You can expand functionality by adding more products or improving error handling. Make sure to test the bot in a safe environment before deploying it to production.