Real-time Chat

An example of building a simple in-memory chat using a hydrated island and the built-in WebSocket support in Bun. The server stores a bounded message history and replays it to new connections; ws.publish() broadcasts each message to all clients. Messages over 4 KB are rejected, frames over 8 KB are dropped by Bun before they are buffered, and a per-client window closes anyone sending more than 20 messages per 10 seconds. Open this page in two tabs to see them sync in real time.

<script>
  import ChatWidget from './ChatWidget.svelte';
</script>

<ChatWidget mochi:hydrate />