True if the device has biometric authentication capability and the current user has enrolled in biometry.
biometryType
BiometryType
The type of biometry available on the device.
reason
string
If biometry is not available and the system gives a reason why, it will be returned here. Otherwise it's an empty string.
AuthenticateOptions
Prop
Type
Description
reason
string
The reason for requesting authentication. Displays in the authentication dialog presented to the user. If not supplied, a default message is displayed.
cancelTitle
string
iOS: The system presents a cancel button during biometric authentication to let the user abort the authentication attempt. The button appears every time the system asks the user to present a finger registered with Touch ID. For Face ID, the button only appears if authentication fails and the user is prompted to try again. Either way, the user can stop trying to authenticate by tapping the button. Android: The text for the negative button. This would typically be used as a "Cancel" button, but may be also used to show an alternative method for authentication, such as a screen that asks for a backup password. Default: "Cancel"
allowDeviceCredential
boolean
* If true, allows for authentication using device unlock credentials. Default is false. iOS: If biometry is available, enrolled, and not disabled, the system uses that first. After the first Touch ID failure or second Face ID failure, if iosFallbackTitle is not an empty string, a fallback button appears in the authentication dialog. If the user taps the fallback button, the system prompts the user for the device passcode or the user’s password. If iosFallbackTitle is an empty string, no fallback button will appear. If biometry is not available, enrolled and enabled, and a passcode is set, the system immediately prompts the user for the device passcode or user’s password. Authentication fails with the error code passcodeNotSet if the device passcode isn’t enabled. If a passcode is not set on the device, a passcodeNotSet error is returned. The system disables passcode authentication after 6 unsuccessful attempts, with progressively increasing delays between attempts. The title of the fallback button may be customized by setting iosFallbackTitle to a non-empty string. Android: The user will first be prompted to authenticate with biometrics, but also given the option to authenticate with their device PIN, pattern, or password by tapping a button in the authentication dialog. The title of the button is supplied by the system.
iosFallbackTitle
string
The system presents a fallback button when biometric authentication fails — for example, because the system doesn’t recognize the presented finger, or after several failed attempts to recognize the user’s face. If allowDeviceCredential is false, tapping this button dismisses the authentication dialog and returns the error code userFallback. If undefined, the localized systetm default title is used. Passing an empty string hides the fallback button completely. If allowDeviceCredential is true and this is undefined, the localized system default title is used.
androidTitle
string
Title for the Android dialog. If not supplied, the system default is used.
androidSubtitle
string
Subtitle for the Android dialog. If not supplied, the system default is used.
androidMaxAttempts
number
The maximum number of failed biometric verification attempts before returning BiometryError.authenticationFailed. The default is 3.