clj-telebot

Hypothesis (draft)

How small can a Telegram bot be in Clojure with no framework — just the HTTP API and a loop?

Stack & constraints

• Clojure + Hato (HTTP) + Cheshire (JSON), long-polling the Bot API.
• Leiningen for build; Java 8+ (CI on Temurin 21).
• yt-dlp and ffmpeg on PATH for video downloads.
• Fails fast: a missing TELEGRAM_BOT_TOKEN throws on the first API call rather than starting half-configured.

What shipped

• Echoes text, reports uptime.
• Downloads videos through yt-dlp with per-chat rate limiting.
• Ships as a standalone jar.

Retrospective (draft)

• The interesting part was not the bot but the boundary: rate limiting and external binaries (yt-dlp/ffmpeg) are where a “tiny” bot stops being tiny.