didit_sdk 4.0.4

Didit Identity Verification SDK for Flutter. Wraps native iOS and Android SDKs for document scanning, NFC passport reading, face verification, and liveness detection.

DiditSDK for Flutter

A Flutter plugin for Didit Identity Verification. Wraps the native iOS and Android SDKs with a unified Dart API for document scanning, NFC passport reading, face verification, and liveness detection.

Requirements

Requirement	Minimum Version
Flutter	3.3+
Dart	3.11+
iOS	13.0+ (NFC requires iOS 15.0+)
Android	API 23+ (6.0 Marshmallow)

Installation

Add the dependency to your pubspec.yaml:

dependencies:
  didit_sdk: ^4.0.4

Then run:

flutter pub get

Native SDK Variants

The Flutter plugin can install the same native SDK variants exposed by the iOS and Android SDKs:

Variant	Automatic capture	NFC passport reading	Use when
all	Yes	Yes	You want the complete SDK (default)
core	No	No	You only need manual capture and the smallest binary
autodetection	Yes	No	You need automatic capture without NFC
nfc	No	Yes	You need NFC passport reading without automatic capture

iOS Setup

The Flutter plugin picks the native iOS SDK variant from $DiditSdkIosVariant, a Ruby global you set in your app's ios/Podfile. The plugin's didit_sdk.podspec reads the same global, so the choice is consistent and — critically — it survives every implicit pod install that flutter build triggers. Configure your ios/Podfile like this:

# Pick one: 'all', 'core', 'autodetection', 'nfc'
$DiditSdkIosVariant = 'all'

didit_sdk_ios_deployment_target = ['all', 'nfc'].include?($DiditSdkIosVariant) ? '15.0' : '13.0'
platform :ios, didit_sdk_ios_deployment_target

didit_sdk_ios_pod = case $DiditSdkIosVariant
                    when 'all'
                      'DiditSDK/All'
                    when 'core'
                      'DiditSDK/Core'
                    when 'autodetection'
                      'DiditSDK/AutoDetection'
                    when 'nfc'
                      'DiditSDK/NFC'
                    else
                      raise "Invalid $DiditSdkIosVariant '#{$DiditSdkIosVariant}'. Supported values: all, core, autodetection, nfc."
                    end
didit_sdk_ios_podspec = 'https://raw.githubusercontent.com/didit-protocol/sdk-ios/4.0.4/DiditSDK.podspec'

target 'Runner' do
  use_frameworks!

  pod didit_sdk_ios_pod, :podspec => didit_sdk_ios_podspec

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = didit_sdk_ios_deployment_target
    end
  end
end

The default variant is all. Variants all and nfc require an iOS 15.0+ deployment target. Variants core and autodetection can target iOS 13.0+.

To change variant, edit the $DiditSdkIosVariant line, then refresh CocoaPods so the previous variant's binaries are not reused:

cd ios
rm -rf Pods Podfile.lock
pod install

$DiditSdkIosVariant is the only mechanism that reliably survives flutter build / flutter run. The plugin also accepts a DIDIT_SDK_IOS_VARIANT environment variable as a CI fallback, but env vars set inline in a shell command (DIDIT_SDK_IOS_VARIANT=nfc flutter build ...) are typically lost the next time Flutter spawns CocoaPods. Prefer the Podfile global.

Android Setup

The Flutter plugin selects the native Android SDK variant from diditSdkAndroidVariant. The default variant is all. To choose another variant, add this to android/gradle.properties:

diditSdkAndroidVariant=autodetection

Supported values are all, core, autodetection, and nfc.

If you use all or nfc, add the following packaging rule to your android/app/build.gradle.kts inside the android block:

android {
    packaging {
        resources {
            pickFirsts += "META-INF/versions/9/OSGI-INF/MANIFEST.MF"
        }
    }
}

This resolves a duplicate metadata file shipped by the SDK's cryptography dependencies (BouncyCastle). Without it the build will fail with a mergeDebugJavaResource error. This rule is not needed for core or autodetection.

Permissions

iOS

Add the following keys to your app's Info.plist:

Permission	Info.plist Key	Description	Required
Camera	NSCameraUsageDescription	Document scanning and face verification	Yes
Microphone	NSMicrophoneUsageDescription	Video recording for liveness checks	Yes
Photo Library	NSPhotoLibraryUsageDescription	Upload documents from device gallery	Yes
NFC	NFCReaderUsageDescription	Read NFC chips in passports/ID cards	If using NFC

<key>NSCameraUsageDescription</key>
<string>Camera access is required for identity verification.</string>
<key>NSMicrophoneUsageDescription</key>
<string>Microphone access is required for liveness verification.</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>Photo library access is required to upload documents.</string>
<key>NFCReaderUsageDescription</key>
<string>NFC is used to read passport chip data for identity verification.</string>

If any required iOS privacy key is missing, iOS terminates the app as soon as the SDK tries to access that protected resource. For example, missing NSCameraUsageDescription causes a crash when the user taps the document camera's take photo button.

NFC Configuration (for passport/ID chip reading)

1. Add NFC Capability in Xcode:

   • Select your target > Signing & Capabilities > + Capability > Near Field Communication Tag Reading

2. Add ISO7816 Identifiers to Info.plist:

   <key>com.apple.developer.nfc.readersession.iso7816.select-identifiers</key>
   <array>
       <string>D23300000045737445494420763335</string>
       <string>A0000002471001</string>
       <string>A0000002472001</string>
       <string>00000000000000</string>
   </array>
   

3. Add an entitlements file with NFC tag reading enabled:

   <key>com.apple.developer.nfc.readersession.formats</key>
   <array>
       <string>TAG</string>
   </array>
   

Make sure the app's provisioning profile includes the NFC Tag Reading capability. If the bundle ID is not configured for NFC in your Apple Developer account, Xcode will fail signing with a missing com.apple.developer.nfc.readersession.formats entitlement.

This NFC configuration is not needed when $DiditSdkIosVariant is 'core' or 'autodetection'.

Android

The following permissions are declared in the native SDK's AndroidManifest.xml and merged automatically:

Permission	Description	Required
INTERNET	Network access for API communication	Yes
ACCESS_NETWORK_STATE	Detect network availability	Yes
CAMERA	Document scanning and face verification	Yes
NFC	Read NFC chips in passports/ID cards	If using NFC

Camera and NFC hardware features are declared as optional (android:required="false"), so your app can be installed on devices without these features. When diditSdkAndroidNfcEnabled=false, the Android NFC permission and feature are not added by the SDK.

Runtime Permissions

The SDK handles Android runtime permission requests automatically. When the user reaches a step that requires camera access:

1. The SDK prompts for camera permission if not already granted
2. If the user denies the permission, an error message is displayed with a "Try Again" button
3. If the user grants the permission, the verification flow continues

You do not need to request camera permission in your app code before calling startVerification() — the SDK manages this internally.

Quick Start

import 'package:didit_sdk/sdk_flutter.dart';

final result = await DiditSdk.startVerification('your-session-token');

switch (result) {
  case VerificationCompleted(:final session):
    print('Status: ${session.status}');
    print('Session ID: ${session.sessionId}');
  case VerificationCancelled():
    print('User cancelled');
  case VerificationFailed(:final error):
    print('Error: ${error.type} - ${error.message}');
}

Integration Methods

The SDK supports two integration methods:

Method 1: API Integration (Recommended for Production)

Your backend creates a session via the Didit API and returns the session token. This gives you full control over session creation, user tracking, and security.

Read more about how the create session API works here: https://docs.didit.me/reference/create-session-verification-sessions

// Your backend creates a session and returns the token
final sessionToken = await yourBackend.createVerificationSession(userId);

// Pass the token to the SDK
final result = await DiditSdk.startVerification(sessionToken);

This approach gives you full control over:

• Associating sessions with your users (vendor_data)
• Setting contact details, expected details, and metadata
• Configuring callbacks per session

Method 2: Unilink Integration (Simpler)

For simpler integrations, the SDK can create sessions directly using your workflow ID — no backend needed:

final result = await DiditSdk.startVerificationWithWorkflow(
  'your-workflow-id',
  vendorData: 'user-123',
  config: DiditConfig(loggingEnabled: true),
);

Note: Advanced session parameters (contact_details, expected_details, metadata) are only available through the API Integration method, where your backend calls the Create Session API directly.

Configuration

Customize the SDK behavior by passing a DiditConfig object:

final result = await DiditSdk.startVerification(
  'your-session-token',
  config: DiditConfig(
    languageCode: 'es',       // Force Spanish language
    fontFamily: 'Avenir',     // Custom font
    loggingEnabled: true,     // Debug logging
  ),
);

Configuration Options

Option	Type	Default	Description
languageCode	String?	Device locale	ISO 639-1 language code (e.g. "en", "fr", "ar")
fontFamily	String?	System font	Custom font family name
loggingEnabled	bool	false	Enable SDK debug logging
showCloseButton	bool	true	Show the close (X) button on verification step screens
showExitConfirmation	bool	true	Show a confirmation dialog when the user attempts to exit
closeOnComplete	bool	false	Auto-dismiss the verification UI when complete
defaultDocumentCamera	CameraLens?	Native default (back)	Lens used when first entering the document capture screen
defaultLivenessCamera	CameraLens?	Native default (front)	Lens used when first entering the liveness (passive face) capture screen
showDocumentCameraSwitchButton	bool	true	Show the in-capture camera switcher on the document screen
showLivenessCameraSwitchButton	bool	true	Show the in-capture camera switcher on the liveness screen

All fields are optional. If no config is provided, the SDK uses sensible defaults matching the native iOS and Android SDKs.

languageCode

Sets the language for the entire verification UI. Pass an ISO 639-1 code (e.g. "en", "fr", "es", "ar"). If not set, the SDK automatically detects the device locale and falls back to English.

// Force French
await DiditSdk.startVerification(token, config: DiditConfig(languageCode: 'fr'));

// Use device locale (default)
await DiditSdk.startVerification(token);

fontFamily

Overrides the font used throughout the SDK UI. The font must be registered in your app's native configuration:

• iOS: Add the font file to your Xcode project and list it in Info.plist under UIAppFonts.
• Android: Place the font file in android/app/src/main/res/font/.

await DiditSdk.startVerification(token, config: DiditConfig(fontFamily: 'Avenir'));

loggingEnabled

Enables verbose debug logging from the native SDK. Useful during development to inspect the SDK's internal state, API calls, and error details. Should be disabled in production.

await DiditSdk.startVerification(token, config: DiditConfig(loggingEnabled: true));

Language Support

The SDK supports 54 languages. If no language is specified, the SDK uses the device locale with English as fallback.

Supported Languages

Language	Code	Language	Code
Albanian	sq	Kazakh	kk
Arabic	ar	Korean	ko
Armenian	hy	Kyrgyz	ky
Bengali	bn	Latvian	lv
Bosnian	bs	Lithuanian	lt
Bulgarian	bg	Macedonian	mk
Catalan	ca	Malay	ms
Chinese	zh	Mongolian	mn
Chinese (Simplified)	zh-CN	Montenegrin	cnr
Chinese (Traditional)	zh-TW	Norwegian	no
Croatian	hr	Persian	fa
Czech	cs	Polish	pl
Danish	da	Portuguese	pt
Dutch	nl	Portuguese (Brazil)	pt-BR
English	en	Romanian	ro
Estonian	et	Russian	ru
Finnish	fi	Serbian	sr
French	fr	Slovak	sk
Georgian	ka	Slovenian	sl
German	de	Somali	so
Greek	el	Spanish	es
Hebrew	he	Swedish	sv
Hindi	hi	Thai	th
Hungarian	hu	Turkish	tr
Indonesian	id	Ukrainian	uk
Italian	it	Uzbek	uz
Japanese	ja	Vietnamese	vi

Camera Settings

Control which camera lens opens by default on the document and liveness capture screens, and whether the in-capture camera switcher is shown to the user.

final result = await DiditSdk.startVerification(
  'your-session-token',
  config: DiditConfig(
    defaultDocumentCamera: CameraLens.back,        // back is the default
    defaultLivenessCamera: CameraLens.front,       // front is the default
    showDocumentCameraSwitchButton: true,          // false to lock to the chosen lens
    showLivenessCameraSwitchButton: true,
  ),
);

If the requested lens isn't present on the device (for example a tablet with no front camera), the native SDK transparently falls back to the first available camera so capture still works. The in-capture camera switcher is also hidden automatically on devices that expose only one camera, regardless of the show…SwitchButton flag.

Advanced Session Parameters

Parameters like contact_details, expected_details, and metadata are only supported through the API Integration method. Your backend creates the session with full parameter support, then passes the session_token to the SDK.

Read more about how the create session API works here: https://docs.didit.me/reference/create-session-verification-sessions

// Your backend handles the full session creation:
// POST /v3/session/ with contact_details, expected_details, metadata, etc.
final sessionToken = await yourBackend.createSession(userId);

// The SDK only needs the token
final result = await DiditSdk.startVerification(sessionToken);

Verification Results

Both startVerification and startVerificationWithWorkflow return a Future<VerificationResult>. The result is a sealed class — use pattern matching to determine the outcome.

Result Types

Type	Description	Fields
VerificationCompleted	Verification flow completed	session (always present)
VerificationCancelled	User cancelled the flow	session (optional)
VerificationFailed	An error occurred	error (always present), session (optional)

SessionData

Property	Type	Description
sessionId	String	The unique session identifier
status	VerificationStatus	approved, pending, or declined

VerificationError

Property	Type	Description
type	VerificationErrorType	Error category (see table below)
message	String	Human-readable error description

Error Types

Error Type	Description
sessionExpired	The session has expired
networkError	Network connectivity issue
cameraAccessDenied	Camera permission not granted
notInitialized	SDK not initialized (Android only)
apiError	API request failed
unknown	Other error with message

Complete Result Handling Example

import 'package:didit_sdk/sdk_flutter.dart';

Future<void> verify(String token) async {
  final result = await DiditSdk.startVerification(token);

  switch (result) {
    case VerificationCompleted(:final session):
      switch (session.status) {
        case VerificationStatus.approved:
          print('Approved! Session: ${session.sessionId}');
          // User is verified — grant access
        case VerificationStatus.pending:
          print('Under review. Session: ${session.sessionId}');
          // Show "verification in progress" UI
        case VerificationStatus.declined:
          print('Declined. Session: ${session.sessionId}');
          // Handle declined verification
      }

    case VerificationCancelled(:final session):
      print('User cancelled.');
      if (session != null) {
        print('Session: ${session.sessionId}');
      }
      // Maybe show retry option

    case VerificationFailed(:final error):
      print('Error [${error.type}]: ${error.message}');
      // Handle error — show retry or contact support
  }
}

API Reference

DiditSdk.startVerification(token, {config})

Start verification with an existing session token.

Parameter	Type	Required	Description
token	String	Yes	Session token from the Didit API
config	DiditConfig?	No	SDK configuration options

Returns: Future<VerificationResult>

DiditSdk.startVerificationWithWorkflow(workflowId, {...})

Start verification by creating a new session with a workflow ID (Unilink Integration).

Parameter	Type	Required	Description
workflowId	String	Yes	Workflow ID that defines verification steps
vendorData	String?	No	Your user identifier or reference
config	DiditConfig?	No	SDK configuration options

Returns: Future<VerificationResult>

Running the Example App

The repository includes a fully functional example app.

iOS

cd example
flutter pub get
cd ios && pod install && cd ..
flutter run

To run on a real device, open example/ios/Runner.xcworkspace in Xcode, configure your signing team, and select your device.

Android

cd example
flutter pub get
flutter run

License

Copyright (c) 2026 Didit. All rights reserved.