API Reference — Flutter

createVerifierSDK(config)

Creates and returns a VerifierSDK instance.

import 'package:vecu_verifier_flutter_sdk/vecu_verifier_flutter_sdk.dart';

final sdk = createVerifierSDK(VerifierConfig(
  stage: DeploymentStage.production,
  bearerToken: 'your-token',
));

Configuration

VerifierConfig constructor parameters:

The SDK automatically resolves the correct endpoint for each stage. The apiBaseUrl property is available for local mock server testing only.

Widgets

VerificationView

Full verification flow widget. Handles loading, QR display, polling, and all result states.

VerificationView(
  sdk: sdk,
  vin: '1HGBH41JXMN109186',
  onApproved: (result) { /* VerificationApproved */ },
  onDenied: (result) { /* VerificationDenied */ },
  onExpired: (result) { /* VerificationExpired */ },
  onError: (error) { /* VerifierError */ },
  decoration: BoxDecoration(...),
  padding: EdgeInsets.all(24),
)

VerificationController

ChangeNotifier-based state manager for building custom verification UI. Manages the full flow (create request, poll, state transitions) and exposes a reactive state for your UI.

final controller = VerificationController(
  sdk: sdk,
  vin: '1HGBH41JXMN109186',
  proximity: const ProximityConfig(thresholdMiles: 5.0),
  onApproved: (result) { /* VerificationApproved */ },
  onDenied: (result) { /* VerificationDenied */ },
  onExpired: (result) { /* VerificationExpired */ },
  onError: (error) { /* VerifierError */ },
);

Properties

Methods

UIState (Sealed Class)

Use pattern matching on controller.state:

switch (controller.state) {
  LoadingState() => // Creating request...
  QRState(:final qrContent, :final expiresAt, :final vin) => // Show QR
  QRExpiredState() => // QR timer expired, show restart
  ApprovedState(:final result, :final vin) => // Verified
  DeniedState(:final result, :final vin) => // Do not release
  ExpiredState(:final result) => // Session expired
  ErrorState(:final error) => // Show error.userMessage
}

Core SDK Methods

createPresentationRequest(vin, [options])

final result = await sdk.createPresentationRequest(
  '1HGBH41JXMN109186',
  CreatePresentationOptions(
    proximity: ProximityConfig(thresholdMiles: 5.0),
  ),
);
if (result is ApiSuccess<CreatePresentationResponse>) {
  final data = result.data;
  // data.requestId, data.qrContent, data.expiresAt
}

ApiResult is a sealed class with two subtypes:

• ApiSuccess<T> — contains data: T
• ApiFailure<T> — contains error: VerifierError

Returns: Future<ApiResult<CreatePresentationResponse>>

CreatePresentationResponse

startPolling()

Starts polling for verification status. Stops automatically on terminal states.

Returns: void Function() — cleanup function to stop polling.

stopPolling({String reason})

Manually stop polling. Accepts an optional reason parameter (defaults to 'manual').

getStatus() / getRequest()

Get current verification status or full request state.

on<T>(listener) / off<T>(listener)

Subscribe/unsubscribe to typed events.

sdk.on<StatusChangedEvent>((event) {
  print(event.currentStatus.status);
});

destroy()

Clean up all resources (timers, listeners).

Events

sdk.on<RequestCreatedEvent>((e) { e.requestId; e.qrContent; e.vin; });
sdk.on<StatusChangedEvent>((e) { e.previousStatus; e.currentStatus; });
sdk.on<PollingStartedEvent>((e) { e.requestId; e.intervalMs; });
sdk.on<PollingStoppedEvent>((e) { e.requestId; e.reason; });
sdk.on<ErrorEvent>((e) { e.error; });

Verification Status Types

Sealed class hierarchy with pattern matching:

All statuses share common fields requestId, createdAt?, and expiresAt?:

switch (status) {
  case VerificationPending(:final requestId):
    print('Waiting...');
  case VerificationApproved(:final requestId, :final proximityCheck):
    print('Verified: $requestId');
    if (proximityCheck?.status == ProximityCheckStatus.fail) {
      print('Warning: device is far from origin');
    }
  case VerificationDenied(:final requestId, :final error):
    print('DO NOT RELEASE: $requestId (${error ?? "no reason"})');
  case VerificationExpired(:final requestId):
    print('Expired: $requestId');
}

Helper methods: status.isTerminal, status.isApproved, status.isDenied

VerificationApproved includes optional verifiedClaims and proximityCheck:

VerifiedClaims

Credential claims extracted by the backend on approval. Access via result.verifiedClaims:

case VerificationApproved(:final verifiedClaims, :final proximityCheck):
  final vin = verifiedClaims?.vin ?? 'N/A';
  final origin = verifiedClaims?.originLocation;
  final destination = verifiedClaims?.destinationLocation;

Proximity Types

ProximityConfig

Device GPS coordinates are retrieved automatically via platform location services. If location permission is not granted, the proximity check result will be unchecked.

const ProximityConfig({
  required double thresholdMiles, // Max distance from origin (miles)
})

ProximityCheck

Returned on VerificationApproved.proximityCheck:

Status behavior:

final proximity = result.proximityCheck;
if (proximity != null && proximity.status == ProximityCheckStatus.fail) {
  print('Device is ${proximity.distanceMiles?.toStringAsFixed(1)} mi '
      'from origin (threshold: ${proximity.thresholdMiles} mi)');
}

Error Types

All errors extend VerifierError with these common fields:

Subtypes:

ApiError.isRetryable returns true for 5xx and 429 status codes. The top-level isRetryableError() function works on any VerifierError.

onError: (error) {
  // Show to user
  showSnackBar(error.userMessage);
  // Log for support
  print('Error ${error.displayCode}: ${error.message}');
}

Individual UI Widgets

For headless integrations that want to reuse specific built-in views, the SDK exports individual widgets: