Catchup

Inspiration

What it does## Inspiration

Plans get made in group chats and then buried under memes. A week later nobody knows if it was Saturday or Sunday, or who was booking.

What it does

Catchup is a Telegram bot you add to a group. Nobody talks to it. It reads the conversation and keeps one pinned message up to date with the plan, who's doing what, and what's still undecided. One person's opinion never closes a decision, unclaimed jobs show as "nobody yet", and banter is ignored. Each plan has a one-tap Add to calendar link.

How we built it

A Node.js server with no dependencies connects to the Telegram Bot API. Each message goes to GPT-OSS 120B on Groq, along with the current board and a computed two-week calendar so the model knows which date "Saturday" means. The server merges the results, removes duplicates and edits the pinned message in place. A small web page shows what the AI picked up from each message.

Challenges we ran into

Models get weekdays wrong, so the server works out the dates itself. Early versions duplicated tasks and closed decisions too early, so we added board context and safety checks.

What we learned

Invisible AI is mostly about restraint: the bot has to stay quiet and only change the pin when something was actually decided.

What's next

Discord and Slack for societies and project teams. WhatsApp is where most friend groups are, but bots can't join personal groups there yet. Reminders the day before. Privacy by design: opt-in only, and we store the plan, not the messages.