> For the complete documentation index, see [llms.txt](https://docs.caf.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.caf.io/caf-sdk/flutter/migrating-from-cafsdk.md).

# Migrating from CafSdk

Migrate a Flutter app from the sequential CafSdk API to Certta DevX in caf\_sdk 2.4.0. Compare configuration, module launch, and event handling.

{% hint style="warning" %}
This guide covers **caf\_sdk 2.4.0** and above (Certta DevX). For the previous `CafSdk` sequential flow, see the [legacy documentation](https://docs.caf.io/caf-sdk/flutter/getting-started-with-the-sdk).
{% endhint %}

Starting with **caf\_sdk 2.4.0**, **Certta DevX** (`CerttaSdk`) is the recommended API for new integrations. The sequential `CafSdk` API remains available in the same package. Existing `initializeCafSdk` flows keep working.

This page maps the legacy sequential API to independent module `open()` calls.

## API comparison

| Area              | CafSdk (legacy)                                                              | Certta DevX (2.4.0+)                                                |
| ----------------- | ---------------------------------------------------------------------------- | ------------------------------------------------------------------- |
| Import            | `package:caf_sdk/caf_sdk.dart`                                               | `package:caf_sdk/certta_sdk.dart`                                   |
| Entry point       | `CafSdk()`                                                                   | `CerttaSdk()`                                                       |
| Session           | `CafSdkConfiguration` + `initializeCafSdk(...)`                              | `configureSdk(CerttaConfiguration)`                                 |
| Module order      | `presentationOrder` runs Face Liveness and Document Detector in one sequence | Each module is opened independently                                 |
| Launch            | One `initializeCafSdk` starts the whole pipeline                             | `liveness.open`, `documentDetector.open`, `documentDetectorUi.open` |
| Events            | Single `eventStream` of `CafResponse`                                        | Per-module streams + `logStream`                                    |
| Person identifier | `personId`                                                                   | `userId`                                                            |
| Security flag     | `CafSdkBuilderConfiguration.enableSecurityModule`                            | `CerttaConfiguration.securityEnabled`                               |
| Colors            | `CafSdkBuilderConfiguration.colorConfiguration`                              | `CerttaConfiguration.colorConfiguration`                            |

Module selection (`caf-modules-config.json`), Maven repositories, CocoaPods, permissions, and ProGuard **do not change**. Follow the [Installation Guide](/caf-sdk/flutter/installation-guide.md).

## 1. Configure the session once

```dart
// Before (CafSdk)
final cafSdk = CafSdk();
await cafSdk.initializeCafSdk(
  cafSdkConfiguration: CafSdkConfiguration(
    mobileToken: 'token',
    personId: 'personId',
    environment: CafEnvironment.prod,
    configuration: CafSdkBuilderConfiguration(
      presentationOrder: [
        CafModuleType.faceLiveness,
        CafModuleType.documentDetector,
      ],
      enableSecurityModule: true,
    ),
  ),
  faceLivenessConfiguration: faceLivenessConfig,
  documentDetectorConfiguration: documentDetectorConfig,
);

// After (Certta)
import 'package:flutter/services.dart';

final certta = CerttaSdk();
try {
  await certta.configureSdk(
    const CerttaConfiguration(
      mobileToken: 'token',
      userId: 'personId',
      environment: CafEnvironment.prod,
      securityEnabled: true,
    ),
  );
} on PlatformException catch (e) {
  // Handle BRIDGE_EXCEPTION
}
```

After `configureSdk`, update credentials without rebuilding the full configuration:

```dart
try {
  await certta.updateUserId('new-user-id');
  await certta.updateMobileToken('new-jwt-token');
} on PlatformException catch (e) {
  // Handle BRIDGE_EXCEPTION
}
```

## 2. Open one module at a time

There is no `presentationOrder` on Certta. Start Face Liveness or Document Detector when your product flow needs it.

```dart
import 'package:flutter/services.dart';

// Face Liveness
try {
  await certta.liveness.open(
    const CerttaLivenessConfiguration(
      maxRetryAttempts: 3,
      faceAuthEnabled: false,
      showLoading: true,
      useFaceLivenessUi: true,
    ),
  );
} on PlatformException catch (e) {
  // Handle BRIDGE_EXCEPTION
}

// Document Detector (headless)
try {
  await certta.documentDetector.open(
    CerttaDocumentDetectorConfiguration(
      flow: [
        CafDocumentDetectorFlow(document: CafDocument.rgFront),
        CafDocumentDetectorFlow(document: CafDocument.rgBack),
      ],
    ),
  );
} on PlatformException catch (e) {
  // Handle BRIDGE_EXCEPTION
}

// Document Detector UI
try {
  await certta.documentDetectorUi.open(
    CerttaDocumentDetectorUiConfiguration(
      flow: [CafDocumentDetectorFlow(document: CafDocument.rgFront)],
    ),
  );
} on PlatformException catch (e) {
  // Handle BRIDGE_EXCEPTION
}
```

| Legacy module config                 | Certta launch                                              |
| ------------------------------------ | ---------------------------------------------------------- |
| `CafFaceLivenessConfiguration`       | `CerttaLivenessConfiguration` (`useFaceLivenessUi: false`) |
| `CafFaceLivenessUIConfiguration`     | `CerttaLivenessConfiguration` (`useFaceLivenessUi: true`)  |
| `CafDocumentDetectorConfiguration`   | `CerttaDocumentDetectorConfiguration`                      |
| `CafDocumentDetectorUIConfiguration` | `CerttaDocumentDetectorUiConfiguration`                    |

Certta liveness configuration is a smaller set: `maxRetryAttempts`, `faceAuthEnabled`, `showLoading`, `useFaceLivenessUi`, and `payFaceDebugMode` (iOS). Proxy URLs, certificates, and Face Liveness instruction-screen fields from `CafFaceLivenessConfiguration` are not part of the Certta configuration object.

## 3. Listen to typed module events

```dart
// Before — one stream, CafResponse
cafSdk.eventStream.listen((event) {
  if (event.success != null) { /* moduleName + signedResponse */ }
  if (event.failure != null) { /* CafFailureType */ }
  if (event.error != null) { /* CafErrorType */ }
  if (event.cancelled) { /* user cancelled */ }
});

// After — subscribe per module (before open)
certta.liveness.eventStream.listen((event) {
  if (event.success != null) { /* JWT in event.success!.response */ }
  if (event.failed != null) { /* CerttaLivenessFailure */ }
  if (event.error != null) { /* CerttaError */ }
});

certta.documentDetector.eventStream.listen((event) {
  if (event.success != null) { /* JWT */ }
  if (event.error != null) { /* CerttaError */ }
});

certta.logStream.listen((log) {
  print('${log.level}: ${log.message}');
});
```

| CafSdk `CafResponse`     | Certta equivalent                                      |
| ------------------------ | ------------------------------------------------------ |
| `success.signedResponse` | `event.success.response`                               |
| `success.moduleName`     | Implied by which stream received the event             |
| `failure`                | `CerttaLivenessEvent.failed` (`CerttaLivenessFailure`) |
| `error`                  | `event.error` (`CerttaError`)                          |
| `cancelled`              | Surfaced as `CerttaError` (`cancelled` / similar type) |
| `log`                    | `CerttaSdk.logStream`                                  |
| `loading` / `loaded`     | Not forwarded on Certta module streams                 |

Bridge mapper rejections throw `PlatformException` with `CerttaErrorCode.bridgeException` (`BRIDGE_EXCEPTION`) instead of only appearing on `eventStream`.

## 4. Sequential pipelines

If you used `presentationOrder`, transition screens (`enableTransitionScreens`), or `waitForAllServices` with CafSdk, the same product flow can be built with Certta DevX: configure the session once, then chain module `open()` calls from your app logic (for example, start Face Liveness when Document Detector emits `success` on `eventStream`).

The sequential `CafSdk` API remains available in `package:caf_sdk/caf_sdk.dart` and is documented in [Legacy Getting Started](/caf-sdk/flutter/getting-started-with-the-sdk.md). Both APIs are supported and cover equivalent integration needs — prefer Certta DevX for new work and when migrating existing apps.

## Next steps

{% content-ref url="/pages/8imRjz3wgDSO5c2vhnO5" %}
[Installation Guide](/caf-sdk/flutter/installation-guide.md)
{% endcontent-ref %}

{% content-ref url="/pages/doA4Dvv8B4ZnWElGVS9V" %}
[Face Liveness](/caf-sdk/flutter/face-liveness.md)
{% endcontent-ref %}

{% content-ref url="/pages/8RhXbzy99UEv0rZV7A3l" %}
[Document Detector](/caf-sdk/flutter/document-detector.md)
{% endcontent-ref %}


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