ADR 0014 Fallback Hotspot

ADR 0014 — Offline fallback Wi‑Fi hotspot

Status: Accepted
Date: 2026-08-07
Companions: admin.qr, Admin Console, ADR 0012

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Context

When the hallway Pi has no ethernet and no client Wi‑Fi, operators cannot reach Admin on :8781. The debug admin QR also has no LAN IP to encode.

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Decision

1. Detect uplink loss; bring up local SoftAP via NetworkManager.
2. Connection id comstar-hotspot, shared IPv4 10.87.65.1/24.
3. SSID COMSTAR-<hostname>, open auth (no WEP/WPA profile).
4. Admin QR uses hotspot IP; envelope includes hotspot: true and ssid.
5. Show QR while hotspot is active even if kiosk debugUi is false.
6. Disable with COMSTAR_HOTSPOT=0.

Join the SSID before scanning the QR (same L2 as 10.87.65.1). Admin token still gates the UI.

Full text: docs/adr/0014-fallback-hotspot.md in the main repo.

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Related

• Admin Console
• Contracts — Bridge ↔ Kiosk
• ADR Index