useBiometry

Biometric authentication using Face ID, Touch ID (iOS), or the device biometric sensor (Android). Provides methods to check availability, detect the biometry type, and prompt the user to authenticate.

Usage

<script setup>
import { useBiometry } from '@thelacanians/vue-native-runtime'

const { authenticate, getSupportedBiometry, isAvailable } = useBiometry()
</script>

API

useBiometry(): {
  authenticate: (reason?: string) => Promise<BiometryResult>
  getSupportedBiometry: () => Promise<BiometryType>
  isAvailable: () => Promise<boolean>
}

Return Value

Method	Signature	Description
`authenticate`	`(reason?: string) => Promise<BiometryResult>`	Prompt the user for biometric authentication. The `reason` string is displayed in the system prompt. Defaults to `"Authenticate"`.
`getSupportedBiometry`	`() => Promise<BiometryType>`	Returns the type of biometric hardware available on the device.
`isAvailable`	`() => Promise<boolean>`	Returns `true` if biometric authentication is available and enrolled.

Types

type BiometryType = 'faceID' | 'touchID' | 'opticID' | 'none'

interface BiometryResult {
  success: boolean
  error?: string
}

Platform Support

Platform	Support
iOS	Uses the `LocalAuthentication` framework (`LAContext`). Supports Face ID, Touch ID, and Optic ID.
Android	Uses `BiometricManager` for availability checks. `authenticate` requires an Activity-level `BiometricPrompt` — override `VueNativeActivity.onAuthenticateRequest()` to provide it.

Example

<script setup>
import { ref, onMounted } from 'vue'
import { useBiometry } from '@thelacanians/vue-native-runtime'

const { authenticate, getSupportedBiometry, isAvailable } = useBiometry()
const biometryType = ref('none')
const available = ref(false)
const status = ref('')

onMounted(async () => {
  biometryType.value = await getSupportedBiometry()
  available.value = await isAvailable()
})

async function handleAuth() {
  status.value = 'Authenticating...'
  const result = await authenticate('Confirm to view sensitive data')
  if (result.success) {
    status.value = 'Authenticated!'
  } else {
    status.value = result.error ?? 'Authentication failed'
  }
}
</script>

<template>
  <VView :style="{ padding: 20 }">
    <VText :style="{ fontSize: 18, fontWeight: 'bold', marginBottom: 12 }">
      Biometric Auth
    </VText>
    <VText>Type: {{ biometryType }}</VText>
    <VText>Available: {{ available ? 'Yes' : 'No' }}</VText>
    <VText v-if="status" :style="{ marginTop: 8 }">{{ status }}</VText>
    <VButton
      v-if="available"
      :onPress="handleAuth"
      :style="{ marginTop: 16 }"
    >
      <VText>Authenticate</VText>
    </VButton>
  </VView>
</template>

Notes

On iOS, add NSFaceIDUsageDescription to your Info.plist to explain why your app uses Face ID. Without this key, the system will terminate your app when Face ID is triggered.
On Android, getSupportedBiometry returns "faceID" as a generic label when strong biometrics are available (Android does not distinguish between face and fingerprint at the API level). It returns "biometric" when hardware is present but not enrolled.
On Android, authenticate requires Activity-level integration with BiometricPrompt. The base CameraModule stub returns an error — override VueNativeActivity.onAuthenticateRequest() to provide the actual prompt.
This composable has no reactive state and no cleanup. All methods return Promises.