Nanfeng

Notes on software development, code, and curious ideas

Forward Telegram Bot Messages to a Server with grammY, Deno and fetch

In ,
Listen for Telegram Bot text messages with grammY on Deno, extract user and message fields, and forward them to an application server as JSON with fetch.

After releasing a Telegram Mini App, we wanted to capture feedback that users might send directly to the bot. The bot listens for text messages and forwards them to our server.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
import { Bot } from "https://deno.land/x/grammy@v1.25.0/mod.ts";

const TOKEN = '';
const serverUrl = 'https://example.com/api/feedback';
const bot = new Bot(TOKEN);

bot.on('message:text', async (ctx) => {
  const payload = {
    uid: ctx.message.chat.id,
    message: ctx.message.text,
  };

  try {
    const response = await fetch(serverUrl, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload),
    });
    if (!response.ok) throw new Error(`HTTP ${response.status}`);
    console.log('Server response:', await response.json());
  } catch (error) {
    console.error('Failed to forward message:', error);
  }
});

bot.start();

Authenticate the server endpoint, validate input, rate-limit requests, and avoid logging sensitive message content unnecessarily.

+