Liveness (biometric selfie)

Biometric selfie capture with embedded liveness verification. The SDK guides the user until a biometrically valid frame is obtained via SmartFrames and returns the image as Base64 + JWT (JSON Web Token — a signed payload sent to your backend to call the REST API).

Capability

This capture type uses the Liveness capability. For a conceptual overview of how Liveness works, refer to the Liveness capability page.

How it works

The SDK manages the full capture session:

Opens the camera with the SmartFrame overlay.
Guides the user to position their face within the frame.
Validates liveness — the session only completes when the user is physically present.
Returns a ResultCamera object with base64 and encrypted (JWT).

Starting a liveness capture

Step 1 — Implement AcessoBioListener

AcessoBioListener handles the SDK lifecycle callbacks. Implement the four mandatory methods:

Method	When it's called
`onErrorAcessoBio(errorBio)`	An error occurred during SDK operation
`onUserClosedCameraManually()`	The user manually closed the camera
`onSystemClosedCameraTimeoutSession()`	The session time limit was reached — see Session limits
`onSystemChangedTypeCameraTimeoutFaceInference()`	The face inference time limit was reached — switches to manual capture — see Session limits

Kotlin
Java

val callback = object : AcessoBioListener {
  override fun onErrorAcessoBio(errorBio: ErrorBio?) { }
  override fun onUserClosedCameraManually() { }
  override fun onSystemClosedCameraTimeoutSession() { }
  override fun onSystemChangedTypeCameraTimeoutFaceInference() { }
}

AcessoBioListener callback = new AcessoBioListener() {
  @Override
  public void onErrorAcessoBio(ErrorBio errorBio) { }

  @Override
  public void onUserClosedCameraManually() { }

  @Override
  public void onSystemClosedCameraTimeoutSession() { }

  @Override
  public void onSystemChangedTypeCameraTimeoutFaceInference() { }
};

Step 2 — Implement iAcessoBioSelfie

iAcessoBioSelfie handles the selfie capture result callbacks:

Method	Description
`onSuccessSelfie(result)`	Capture succeeded — returns `ResultCamera` with `base64` (preview) and `encrypted` (JWT for the API)
`onErrorSelfie(errorBio)`	Capture failed — returns an `ErrorBio` with code and description

Token expiry

The interval between generating encrypted and submitting it to the API must not exceed 10 minutes.

Kotlin
Java

val selfieListener = object : iAcessoBioSelfie {
  override fun onSuccessSelfie(result: ResultCamera?) { }
  override fun onErrorSelfie(errorBio: ErrorBio?) { }
}

iAcessoBioSelfie selfieListener = new iAcessoBioSelfie() {
  @Override
  public void onSuccessSelfie(ResultCamera result) { }

  @Override
  public void onErrorSelfie(ErrorBio errorBio) { }
};

Step 3 — Call prepareCamera

With unicoCheckCamera initialized and both listeners implemented, call prepareCamera passing the SDK config (the UnicoConfig created in Initialization) and a SelfieCameraListener:

onCameraReady — camera is ready; call open passing the selfieListener from Step 2.
onCameraFailed — camera preparation failed; handle the error message.

Kotlin
Java

unicoCheckCamera
  .prepareCamera(UnicoConfig(), object : SelfieCameraListener {
    override fun onCameraReady(cameraOpener: UnicoCheckCameraOpener.Selfie?) {
      cameraOpener?.open(selfieListener)
    }
    override fun onCameraFailed(message: String?) { }
  })

unicoCheckCamera
  .prepareCamera(new UnicoConfig(), new SelfieCameraListener() {
    @Override
    public void onCameraReady(UnicoCheckCameraOpener.Selfie cameraOpener) {
      cameraOpener.open(selfieListener);
    }

    @Override
    public void onCameraFailed(String message) { }
  });

For the full result handling, see Receiving the result.