# 2️⃣ Read MRZ

The Machine Readable Zone - MRZ contains the information that acts as "[proof of authorization](https://www.icao.int/Security/FAL/PKD/BVRT/Pages/Document-readers.aspx)" to access the chip content. If machine-reading of the MRZ is not possible the information can be entered manually.

### Api Signature

{% tabs %}
{% tab title="Android" %}

```kotlin
    fun readMRZ(onCompletion: (DocumentResult<MRZDocument>) -> Unit)
```

{% endtab %}

{% tab title="iOS" %}

```swift
 public static func readMRZ(
        completion: @escaping (Result<MrzDocument, KeylessDocument.DocumentError>) -> Void
    )
```

{% endtab %}

{% tab title="Flutter" %}

```dart
Future<DocumentResult<MRZDocument>> readMRZ()
```

{% endtab %}
{% endtabs %}

### Returned result

If the Keyless Document SDK can read the MRZ it will return an instance of `MRZDocument` containing the data read.

{% tabs %}
{% tab title="Android" %}

```kotlin
data class MRZDocument(
    val documentNumber: String,
    val dateOfBirth: String,//Format as yy-MM-dd
    val dateOfExpiration: String,//Format as yy-MM-dd
    val personalNumber: String? = null,
    val firstName: String? = null,
    val lastName: String? = null,
    val nationality: String? = null,
    val issuingState: String? = null,
    val documentType: String? = null,
    var gender: String? = null
)
```

{% endtab %}

{% tab title="iOS" %}

```swift
public struct MrzDocument {
    public let documentNumber: String
    public let birthdate: String
    public let expirationDate: String
}
```

{% endtab %}

{% tab title="Flutter" %}

```dart
class MRZDocument {
  final String documentNumber;
  final String dateOfBirth; // Format: yy-MM-dd (e.g., 23-05-15)
  final String dateOfExpiration; // Format: yy-MM-dd (e.g., 23-05-15)
  final String? personalNumber;
  final String? firstName;
  final String? lastName;
  final String? nationality;
  final String? issuingState;
  final String? documentType;
  final String? gender;
}
```

{% endtab %}
{% endtabs %}

### Errors

In case of errors the Keyless Document SDK will return the following errors:

{% tabs %}
{% tab title="Android" %}

```kotlin
public sealed class DocumentError(
    public open val code: Int,
    public open val message: String,
) 

// errors launching the MrzCameraActivity
public data class InternalError(override val code: Int) : DocumentError(code, "Internal error")

public data object UserCancelled : DocumentError(
	code = 5000,
    message = "User cancelled the operation."
)

public data object LauncherNotInitialized : DocumentError(
    code = 5002,
    message = "Launcher is null or not initialized"
)

public data object PermissionDenied : DocumentError(
    code = 7001,
    message = "Permission denied."
)

public data class UnknownError( override val message: String) : DocumentError(
    code = 9999,
    message = message
)
```

{% endtab %}

{% tab title="iOS" %}

```swift
public enum DocumentError: Error {

        case userCancelled
        case cannotCalculateMRZKey
        case cameraUnavailable
        case cameraPermissionDenied
        case unknownError(message: String)

       public var code: Int {
            switch self {
                case .userCancelled: return 5000
                case .cameraUnavailable: return 6001
                case .cannotCalculateMRZKey: return 6002
                case .cameraPermissionDenied: return 6004
                case .unknownError: return 9999
            }
        }

        public var message: String {
            switch self {
                case .userCancelled: return "User cancelled the operation"
                case .cannotCalculateMRZKey: return "Failed to calculate MRZ key"
                case .cameraUnavailable: return "Camera is unavailable"
                case .cameraPermissionDenied: return "Permission denied"
                case .unknownError(let message): return message
            }
        }
}
```

{% endtab %}

{% tab title="Flutter" %}

```dart
enum DocumentError {
  internalError,
  userCancelled,
  launcherNotInitialized,
  permissionDenied,
  cannotCalculateMRZKey,
  cameraUnavailable,
  cameraPermissionDenied,
  unknownError;
```

{% endtab %}
{% endtabs %}

### Example usage

{% tabs %}
{% tab title="Android" %}

```kotlin
KeylessDocument.readMRZ {
    when (it) {
        is DocumentResult.Success -> {
            Log.d(TAG, "MRZ data ${it.value}")
 		}
    	is DocumentResult.Failure -> {
            Log.d(TAG, "MRZ error ${it.error}")
        }
}
```

{% endtab %}

{% tab title="iOS" %}

```swift
KeylessDocument.readMRZ { result in
    switch result {
    case .success(let document):
        print("MRZ data: \(document)")
    case .failure(let error):
        print("MRZ error: \(error)")
    }
}
```

{% endtab %}

{% tab title="Flutter" %}

```dart
DocumentResult<MRZDocument> documentResult = await KeylessDocument.instance.readMRZ();

switch (documentResult) {
    case DocumentSuccess<MRZDocument>(data: final mrz):
        String mrzData = 'MRZ: ${mrz.documentNumber}, ${mrz.dateOfBirth} ${mrz.dateOfExpiration}';
        break;
    case DocumentFailure(message: final error, code: final code, errorType: final type):
        String error = 'MRZ Error: $error $code ($type)';
        break;
```

{% endtab %}
{% endtabs %}