Script to listen to Telegram messages as a user, filter by keywords and push it to slack or do whatever you need. Using Telethon.

telegram_read_and_publish.py

from telethon import TelegramClient, events, sync
import re, requests

# Remember to use your own values from my.telegram.org!
api_id = '...'
api_hash = '...'
username = '...'
channel_name = '...'
slack_webhook_url = '...'
client = TelegramClient(username, api_id, api_hash)

@client.on(events.NewMessage(chats=channel_name))
async def my_event_handler(event):
    text = event.raw_text

    if re.search("(any|keyword|to|filter)", text, re.I):
      print(text)
      obj = {'text': "https://t.me/" + channel_name + "/" + str(event.message.id)}
      requests.post(slack_webhook_url, json = obj)
      print('slacked!')

client.start()
client.run_until_disconnected()