Slash commands reply twice in Chat UI (`/command`) but produce single clean output in Terminal

[edwardcodelab]

Slash commands (e.g. /status, /model, /cost, /theme, /doctor) trigger duplicate replies when submitted through the web Chat UI. The same commands behave correctly (exactly one response) in the interactive terminal.

[chauncygu]

Hi @edwardcodelab , Thanks for your useful feedback.
Confirmed and fixed, please see the latest version (just updated).

Root cause: web/api.py:handle_slash_sync (HTTP /api/prompt) and handle_slash_stream (SSE) both returned events inline in the response payload and re-broadcast them to the live WebSocket of the same client. chat.js iterates data.events and fires _handleEvent from ws.onmessage, so every reply is rendered twice. The terminal has no parallel WS path, which is why it always rendered once.

Fix: synchronous slash-command events now flow through a single channel (HTTP/SSE only). Background-thread events from sentinel flows and long-running commands are unaffected because _broadcast is restored before any worker thread emits.

Thanks again for your feedback.

Best,