Scrape Telegram channel for changes

Question

Can anyone point me to a way to programatically check for changes in a Telegram room? I can't decipher the API. I want to do something like:

telegram.onMessageReceived('room_id', (msg) => {
  console.log(msg.content);
}

I usually use Python, but open to using NodeJS because I want to have it always running, monitoring for changes on an Ubuntu server.

As far as I can find on the internet, everything is pointing to the bot API, but as I understand it, it would only be notified of updates to messages to the bot. I want to monitor public rooms in which I cannot add the bot as an administrator since I did not create the room. Or is there some way to add a bot to public rooms? I don't think so.

Also the room I want to monitor doesn't allow anyone to chat. It's just to notify subscribers.

I've read these SOs so far and am still confused:

Can a Telegram bot read messages of channel

How do I join my bot to the Channel?

How to join my Telegram Bot to PUBLIC channel

Answer 1

in node.js telegram library you can check the last message.date and compare with last date you have stored. if changed there is new message