IntelliToggle OpenFeature client provider for Dart

This package connects Dart, Flutter, and Dart web applications to IntelliToggle through the static-context OpenFeature Dart Client SDK. It includes a web-compatible remote OFREP provider and a no-network snapshot provider.

The upstream client SDK is available from pub.dev as 0.0.1-beta.1.

The Flutter beta demo validates this provider in a real Flutter web application without adding Flutter to the provider's dependency graph. The standalone Dart web smoke target lives at test/web_compile_smoke.dart.

Security model

The application backend authenticates with IntelliToggle and mints a short-lived evaluation token for the current subject. The client uses that token only with IntelliToggle's /ofrep/v1/evaluate/flags endpoint. Never send an IntelliToggle OAuth client ID and secret to a browser or mobile application.

Flags are not an authorization boundary. Paid entitlements, permissions, ad-free status, and other product policy remain authoritative on the backend.

Use remote OFREP evaluation

Your application backend should expose an authenticated endpoint that obtains an IntelliToggle evaluation token from POST /api/v1/ofrep/evaluation-token. The browser or Flutter application supplies that short-lived token to the provider:

import 'dart:convert';

import 'package:http/http.dart' as http;
import 'package:openfeature_provider_intellitoggle_client/openfeature_provider_intellitoggle_client.dart';

Future<void> configureFlags(String signedInUserId) async {
  final provider = IntelliToggleRemoteClientProvider(
    apiBaseUri: Uri.parse('https://api.intellitoggle.com'),
    tokenProvider: (context) async {
      // This is your application backend, authenticated as the signed-in user.
      final response = await http.post(
        Uri.base.resolve('/api/feature-token'),
        headers: {'content-type': 'application/json'},
        body: jsonEncode({'targetingKey': context.targetingKey}),
      );
      return (jsonDecode(response.body) as Map<String, dynamic>)['token']
          as String;
    },
  );

  await OpenFeatureAPI.instance.setEvaluationContextAndWait(
    EvaluationContext(targetingKey: signedInUserId),
  );
  await OpenFeatureAPI.instance.setProviderAndWait(provider);

  final client = OpenFeatureAPI.instance.getClient('my-app');
  final enabled = client.getBooleanValue('checkout-v2', false);
  print('checkout-v2: $enabled');
}

The provider bulk-loads evaluated flags during initialization and every context change. It keeps resolutions synchronous, sends If-None-Match during an explicit refresh(), and atomically drops the old subject's values before reconciliation. It depends only on pure Dart, web-compatible packages.

The token endpoint binds the targeting key, tenant, and environment for at most 15 minutes. Your backend must send its OAuth access token plus x-tenant-id and x-environment; the OAuth client needs flags:evaluate.

Use a backend-resolved snapshot

For applications that proxy all evaluation through their own backend, the snapshot provider remains available and performs no network or authentication work:

import 'package:openfeature_dart_client_sdk/openfeature_dart_client_sdk.dart';
import 'package:openfeature_provider_intellitoggle_client/openfeature_provider_intellitoggle_client.dart';

Future<void> main() async {
  final provider = IntelliToggleClientProvider.fromValues({
    'ads-enabled': true,
    'ad-format': 'sponsored-video',
  });

  await OpenFeatureAPI.instance.setProviderAndWait(provider);
  final client = OpenFeatureAPI.instance.getClient('mobile-app');

  final adsEnabled = client.getBooleanValue('ads-enabled', false);
  final adFormat = client.getStringValue('ad-format', 'none');

  print('$adsEnabled: $adFormat');
  await OpenFeatureAPI.instance.shutdown();
}

When the backend returns a refreshed snapshot, replace the local values:

provider.replaceValues({
  'ads-enabled': false,
  'ad-format': 'none',
});

Snapshot replacement emits an OpenFeature configurationChanged event. The event contains only keys whose values or evaluation details actually changed.

For decoded backend JSON, prefer the full snapshot contract so evaluation details survive the network boundary:

{
  "flags": {
    "ads-enabled": {
      "value": true,
      "reason": "TARGETING_MATCH",
      "variant": "on",
      "metadata": {"source": "backend"}
    }
  }
}

Pass the decoded object to IntelliToggleClientSnapshot.fromJson. A flat {"ads-enabled": true} object is also accepted as a shorthand and uses the default CACHED reason. Flag values must be non-null JSON values; metadata values must be booleans, strings, or numbers. JSON integer values are widened when resolving a double flag, but doubles are not truncated for integer flags.

Changing the OpenFeature evaluation context immediately invalidates the old snapshot so values resolved for one user cannot be served to another. Fetch a new backend-resolved snapshot and call replaceSnapshot after login, logout, account, or other relevant context changes.

Provider instances are single-use. The SDK shuts a provider down when it is no longer bound; check isShutDown before a background refresh. Calls to replaceSnapshot and replaceValues after shutdown throw StateError, and a shut-down instance must not be registered again.

PairQueue can continue consuming its existing server-side flag payload and can adopt the remote client provider when it needs OpenFeature-controlled Flutter UI behavior.