Requirements

React Native

• React Native 0.74+, with the New Architecture (Fabric/TurboModules) enabled.
• There is no old-bridge/Paper support at all - the library is built exclusively as a set of TurboModules with Codegen specs. If your app hasn't turned on the New Architecture, none of this will link.
• No hooks are exported by the library. If you want a useYubiKey-style hook, you build it yourself around Core.addYubiKeyListener (see Usage).

iOS

• Xcode recent enough to build RN 0.74+/New Architecture apps.
• Deployment target 16.4+ recommended. USB-C "smart card" connections (YKFSmartCardConnection) are gated to iOS 16+ in the native code; Lightning/MFi accessory connections (YKFAccessoryConnection) work on older iOS versions supported by the underlying SDK.
• CocoaPods: the library depends on the YubiKit pod, but the version published to the CocoaPods trunk (currently 4.4.0) is too old - this library needs 4.7.0+ APIs (PIV slot/bio metadata, key deletion, FIDO2 minPinLength, Management.deviceReset). You must override the Podfile to pull YubiKit iOS SDK 4.7.0 directly from GitHub. See Installation for the exact snippet.
• None of the transport-specific entitlements are added automatically. Depending on which transports you need, you must manually add: the com.yubico.ylp external accessory protocol (Lightning/5Ci), the com.apple.security.smartcard entitlement (USB-C on iOS 16+), and the NFC reader-session capability plus NFCReaderUsageDescription and AID list (NFC). See Installation for the exact snippets - the library's own example app doesn't configure any of these either.

Android

• minSdkVersion 24, compileSdkVersion 36.
• Kotlin 2.0.21, Java 17 source/target compatibility, AGP 8.7.2.
• Bundles YubiKit Android SDK 3.1.0 (pinned - a newer 3.2.0 requires compileSdk 37/AGP 9.1+, which isn't compatible with current Expo/RN tooling used by this library).
• The library's own AndroidManifest.xml already declares android.hardware.usb.host (required="false") and the NFC permission - these merge into your app automatically. You do not need to add them yourself.
• There is no USB_PERMISSION Android permission string - that's not a real Android permission constant. USB host access is granted at runtime through UsbManager's own permission-request flow, not through a manifest <uses-permission> entry.

Device compatibility

Any YubiKey with the relevant application (OATH, PIV, OpenPGP, YubiOTP, FIDO2) enabled should work, subject to the per-module iOS gaps listed on the index page. Because there's no CTAP1/U2F implementation, YubiKeys or security keys that only speak classic U2F (no CTAP2) won't work with the Fido module.

Verification checklist

• React Native 0.74+ with New Architecture turned on (newArchEnabled=true on Android, Fabric enabled in the iOS Podfile)
• iOS Podfile overridden to pull YubiKit 4.7.0 from GitHub (not the CocoaPods-trunk version)
• iOS Info.plist has NFCReaderUsageDescription and the NFC reader-session capability, if you need NFC
• Android minSdkVersion is at least 24
• You are not manually declaring a USB_PERMISSION permission on Android - it isn't real