Type a nickname, send a message — everyone connected sees each other's message stream in realtime, and your own messages are highlighted on the right. Receiving uses the browser-native EventSource (SSE); sending uses POST …/messages. AI agents can subscribe to the same message stream via MCP's watch_topic.
When several people open this page at once, each message carries a per-tab random cid — only messages sent from your own tab are highlighted on the right; others appear on the left. Messages are published to the same topic as { app:"chat", user, text, ts }.