For AI agents: fetch the complete documentation index at /llms.txt, the full documentation corpus at /llms-full.txt, the agent skill at /skill.md, or this page as Markdown at /docs/mobile/security.md (or send Accept: text/markdown).
App lock and device security
Biometric unlock, session management, and connected accounts.
Enable the app lock
Settings → Security offers a biometric app lock through expo-local-authentication — Face ID, Touch ID, or fingerprint, with the device PIN as an allowed fallback. Enabling requires one successful authentication; disabling is free. The Face ID usage string ships in app.json.
When the lock engages
The gate locks on cold start and after more than sixty seconds in the background. Signed-out users are never locked, and the brief iOS active state that follows a biometric prompt cannot re-lock the app accidentally.
The lock screen
It auto-prompts once per mount, offers a manual Unlock retry, and keeps a Sign out escape. Signing out unregisters the push token before destroying the session — the unregister call needs the live cookie — and a failed sign-out keeps the gate closed with an error instead of opening the app.
Sessions, connected accounts, and export
The same screen lists sessions through the auth client — newest first with the current one flagged — and supports revoking one session or every other session. Connected accounts list under Settings → Connections; the last sign-in method cannot be disconnected, and commerce or Stripe Connect management stays on the web. GET /api/account/export downloads the member's full data export.
Verification and troubleshooting
Lock and unlock, background the app past the grace period, revoke a second session, and sign out from the lock screen. A device without enrolled biometrics cannot enable the lock — the toggle must explain that rather than silently fail.