Genkit Vertex Auth

Shared Vertex AI authentication and project-resolution helpers for Genkit Dart provider plugins.

Features

• ADC and service-account access token providers for Vertex AI.
• Cached token refresh with a safety skew.
• Common project ID resolution for GOOGLE_CLOUD_PROJECT and GCLOUD_PROJECT.
• Shared x-goog-api-client header builder for Genkit providers.

Usage

import 'package:genkit_vertex_auth/genkit_vertex_auth.dart';

void main() {
  final provider = createAdcAccessTokenProvider();
  final projectId = resolveEnvironmentProjectId();
  final header = googleApiClientHeaderValue();

  print('projectId: $projectId');
  print('header: $header');
  print('provider: ${provider.runtimeType}');
}