Proof

expo-secure-store

real upstream package — not intercepted. the app's expo-secure-store JS runs over the ExpoSecureStore native module, backed by tenant-scoped IndexedDB records encrypted with AES-GCM via WebCrypto. Bun/test environments without IndexedDB use the same encrypted record format in memory. (same golden-rule native-seam tier as expo-crypto / expo-network: upstream JS runs unmodified, every gap is a physically-absent-on-an-iOS-sim feature.)

95%

API coverage

No visual proof cases have been published for this package yet. The registry summary below describes what the compat layer implements.

Working (8)

upstream validation and constantsgetItem/setItem sync APIs over the hydrated in-process cachegetItemAsync/setItemAsync/deleteItemAsync async APIsisAvailableAsynccanUseBiometricAuthentication falsekeychainService/accessGroup/requireAuthentication storage partitioningAES-GCM encrypted storage records with per-record salt/iv and tenant-scoped PBKDF2 key derivationpersists across reloads when IndexedDB is available

Missing (3)

canUseBiometricAuthentication always false (no biometric prompt available on web — correct unavailable shape)requireAuthentication not enforced beyond storage partitioning/encryption (no biometric prompt to require)keychainAccessible does not affect browser storage access. sync reads cannot synchronously cold-load IndexedDB after a fresh worker boot; async reads hydrate the cache. all of these are honest absent-on-web semantics — apps with graceful-degradation paths behave correctly.