CatchUp

Inspiration

Joining a stream halfway through feels like walking into a movie at the 40-minute mark. Chat is full of inside jokes, and the streamer has to keep explaining what just happened. We wanted a way for new viewers to catch up on their own, so streamers can keep going.

What it does

CatchUp listens to a channel's chat and stream events (raids, subs, polls, predictions) and keeps a short, live summary of the stream. Viewers open it as a panel or type !catchup in chat to get a quick recap.

How we built it

• Used Codex to scaffold, write and refactor most of the codebase
• Connected to Twitch with EventSub (events) and the Twitch API (channel/stream info)
• A small backend groups messages into time windows and summarizes them
• A lightweight frontend shows the recap to viewers

Challenges we ran into

• Fast chat is noisy: emote spam and copypasta drown out what actually happened
• Getting Twitch auth scopes and EventSub subscriptions right
• Keeping recaps short and accurate without spoilers or made-up details

What we learned

• How Twitch's event system works from start to finish
• How to work with Codex as a pair programmer: give it small, clear tasks and review every diff

What's next

Streamer-side moderation of recaps, clip links inside recaps, and multi-language support.

Built With

• codex
• css
• eventsub
• fastapi
• html
• javascript
• openai
• python
• twitch
• twitch-chat
• twitch-extensions
• websockets