A small Dockerized Telethon stack that logs into Telegram as your user account, finds a channel, and dumps its entire history to JSON — then turns that into a grep-able TSV, a timeline rollup, and a chunked transcript. Used to archive the Tevm Smithereans channel back to message #1.
This trips people up: a Telegram bot cannot read a channel's history. Even after you add a bot to a channel, the Bot API only delivers messages posted after it joined, and only with privacy mode configured. To copy a channel from the beginning you log in as a user account that is a member of the channel — that account can page back through the full history. Telethon (MTProto) does exactly this. The "add our bot to the channel" step is irrelevant to the copy; it's the user session that does the work.
Use an account that's actually a member of the channel, and respect the channel's no