python-telegram-bot

python-telegram-bot wraps Telegram's Bot API so you can build a bot without hand-rolling HTTP calls. It covers the whole API and adds higher-level helpers for handling commands, messages, and updates, so a working bot is a short script rather than a weekend. Mature, well-documented, LGPL-3.0, and free to install with pip.

It is built entirely on asyncio, which is the modern way to do this and also the main thing to know going in: it is explicitly not thread-safe, so it does not slot cleanly into multi-threaded designs. For the overwhelming majority of bots, that is a non-issue, you write async handlers and move on. The library has almost no running cost and the maintainers are clear they are not chasing donations or a business model.

Building anything on Telegram in Python, from a personal notification bot to a production service handling real traffic, this is the standard choice. Solo and team alike: free, no tiers, no gated features. The only reason to skip it is if you are not on Python, or you need a single one-off API call where the full library is more than you want.

The catch is small but worth naming: asyncio-only and not thread-safe. Design around that from the start and you will never feel it. Bolt it onto a threaded app late and you will.