crypto.randomUUID() is only exposed on secure contexts (HTTPS, localhost,
127.0.0.1, ::1). When Velxio is self-hosted and accessed via a LAN IP over
plain HTTP (e.g. http://192.168.31.139:3080/), crypto.randomUUID is
undefined and any code path that calls it throws TypeError.
This silently broke ESP32 simulation start for self-hosters: the frontend
generates a UUID for the WS client_id when Run is clicked; the throw
rejected the promise before reaching the WS connect, so the backend
never got the start request — no worker spawned, logs empty, simulation
"didn't start" with no visible error.
Same root cause would also break the multi-file editor (createFile,
createFileGroup) on the same LAN-HTTP self-host setup, just less
observably.
Add a single generateUUID() helper that:
1. Uses crypto.randomUUID() when available (secure context fast path).
2. Falls back to crypto.getRandomValues() — which IS available in
non-secure contexts — to build a v4 UUID by hand.
3. Final fallback to Math.random() if even that is missing
(defensive — Web Crypto getRandomValues has been universal for
years).
Replace all 6 crypto.randomUUID() call sites:
- frontend/src/simulation/Esp32Bridge.ts (2 sites — getTabSessionId)
- frontend/src/store/useEditorStore.ts (4 sites — file IDs)
Reported by a self-hoster on OrangePi 5B accessing Velxio via LAN IP.
DevTools console showed:
TypeError: crypto.randomUUID is not a function
at Ph (...) at wh.connect (...) at startBoard (...)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
David Montero Crespo