Summarizer

A sidebar widget that reads the messages you have not caught up on and posts a short AI-generated summary, so you can rejoin a busy room without scrolling back through everything.

When opened, it looks at the room timeline up to your read marker (m.fully_read), collects the unread m.room.message events, resolves the senders from m.room.member, and asks an LLM to condense them. The summary is shown inside the widget — nothing is written back to the room.

Built by Beeper as a demo for their widget SDK. It runs against Beeper's fork of the Matrix Widget API (@beeper/matrix-widget-api) and needs a companion backend that holds an Anthropic API key: the widget's own Next.js API route (/api/completion) proxies the request to the Claude API so the key never reaches the browser. Because of that server route — and because the repo carries no license — it is listed here only, pointing at Beeper's own deployment, and is not built or hosted by Marcade.