[FIXED] Telethon: Get response from bot when started with parameter using telethon

Issue

The goal I'm trying to achieve is to send a command (e.g. /price) and get the response (price stats) from the bot and then quit to save resources. The message can only be received on-demand since the bot only responds when a command is sent.

So far, I've only gotten halfway there successfully by sending the command but receiving the response has been a head-scratcher. Here's my attempt so far, I'm open to any suggestions, please advise on the simplest way to achieve the receiving part. Thanks much!

with TelegramClient('Anon', tg_API_ID, tg_API_Hash) as client:
    client(functions.messages.StartBotRequest(bot = '@Bot', peer = '@myHandle', start_param = '/price'))
    client.start()
    session = os.environ.get('TG_SESSION', 'printer')
    @client.on(events.NewMessage(chats = '@Bot'))
    async def my_event_handler(event):
        text = event.raw_text
        print(text) 
    client.loop.run_until_complete(main())

Here's a good resource if it helps: https://tl.telethon.dev/methods/messages/index.html

Solution

In Telethon V1, with client also calls start, so adding it again is redundant.

It's probably a good idea to define the handler before starting the bot, in case the message arrives "in-between".

You can call disconnect from the handler to disconnect the client, and run_until_disconnected to behave like loop.run_until_complete, but it runs the event loop until disconnection occurs instead.

The following should work, assuming telethon.sync was imported:

text_found = None

with TelegramClient('Anon', tg_API_ID, tg_API_Hash) as client:
    @client.on(events.NewMessage(chats = '@Bot'))
    async def my_event_handler(event):
        global text_found
        text_found = event.raw_text
        await client.disconnect()
    client(functions.messages.StartBotRequest(bot = '@Bot', peer = '@myHandle', start_param = '/price'))
    client.run_until_disconnected()

print(text_found)

If telethon.sync was not imported, you must use asyncio, async and await:

import asyncio

async def main():
    text_found = None

    async with TelegramClient('Anon', tg_API_ID, tg_API_Hash) as client:
        @client.on(events.NewMessage(chats = '@Bot'))
        async def my_event_handler(event):
            nonlocal text_found
            text_found = event.raw_text
            await client.disconnect()
        await client(functions.messages.StartBotRequest(bot = '@Bot', peer = '@myHandle', start_param = '/price'))
        await client.run_until_disconnected()

    return text_found

text_found = asyncio.run(main())
print(text_found)

Answered By - Lonami