Initializing the SDK

To use the SDK’s methods and classes, your application must call the SDK’s initialize method to initialize the MobileCredentialHolder class.

MobileCredentialHolder.getInstance().initialize(activity)

Initialize a specific instance

You can initialize this singleton class with one instanceId at a time:

MobileCredentialHolder.getInstance().initialize(activity, instanceId = "user-2")

Once initialized, all subsequent method calls in this class will only return results specific to this instanceId.

If no instanceId is provided, the default instance is initialized (00000000-0000-0000-0000-000000000000).

Configure authentication requirements

You can configure the method to require user authentication (biometric or passcode) upon initialization using the optional userAuthRequiredOnInitialise parameter:

MobileCredentialHolder.getInstance().initialize(activity, userAuthRequiredOnInitialize = false)

UX Considerations

Setting userAuthRequiredOnInitialize to true would require the user to authenticate when initializing the SDK.

Configure credential issuance

When initializing the SDK, you should also configure the values required for credential issuance:

MobileCredentialHolder.getInstance().initialize(
    activity,
    credentialIssuanceConfiguration = CredentialIssuanceConfiguration(
        redirectUri = Constants.REDIRECT_URI,
        autoTrustMobileCredentialIaca = true
    )
)

• redirectUri : This parameter is used by the issuer to redirect the user back to a specific view in your application after completing the configured OID4VCI workflow.
  • It must be defined as a resource in your application project, as shown in the Claim a credential  tutorial.
  • It must be registered as a key pair with clientId as part of the issuer’s OID4VCI workflow configuration.
• autoTrustMobileCredentialIaca :
  • When set to true, this request will accept credentials from any issuer. The SDK will retrieve the IACA referenced in the offered credential and add it to the list of trusted issuers in the application storage.
  • When set to false, this request will only accept credentials issued by trusted issuers, identified by their IACA certificate. This means the IACA referenced in the offered credential must exist in the application’s trusted issuers list prior to accepting the credential offer.

See the Claim and manage credentials usage guide for more details.

Configure logger behavior

You can configure the SDK’s logger behavior using the optional loggerConfiguration parameter:

MobileCredentialHolder.getInstance().initialize(
    activity,
    loggerConfiguration = Logger.LoggerConfiguration(
        logLevel = Logger.LogLevel.DEBUG,
        callbackLogLevel = Logger.LogLevel.DEBUG,
        callback = { priority, tag, message, error ->
            Logger.d("Perform any custom action with the log event: $message")
        }
    )
)

• logLevel : Determines which events are written to logs.
• callbackLogLevel : Determines which events invoke the callback function.
• callback : Defines the function to call when events defined by callbackLogLevel occur.

Logging levels

These levels apply to both the logLevel and callbackLogLevel parameters (corresponding raw value in shown in parenthesis):

• Off (7).
• Assert (7).
• Error (6).
• Warning (5).
• Info (4).
• Debug (3).
• Verbose (2).