Firebase Remote Config Skill

This skill defines how to correctly use Firebase Remote Config in Flutter applications.

When to Use

Use this skill when:

• Setting up Remote Config to configure your app without deploying updates.
• Managing parameter defaults and remote values.
• Fetching, activating, and listening to config updates.
• Applying throttling, A/B testing, or conditional targeting.

1. Setup and Configuration

flutter pub add firebase_remote_config
flutter pub add firebase_analytics  # required for conditional targeting of app instances

import 'package:firebase_remote_config/firebase_remote_config.dart';

final remoteConfig = FirebaseRemoteConfig.instance;

• Enable Google Analytics in your Firebase project for user property and audience targeting.
• Ensure the Remote Config REST API is not disabled — the SDK depends on it.
• For macOS, enable Keychain Sharing in Xcode.

Configure settings:

await remoteConfig.setConfigSettings(RemoteConfigSettings(
  fetchTimeout: const Duration(minutes: 1),
  minimumFetchInterval: const Duration(hours: 1),
));

2. Parameter Management

Set in-app defaults (ensures your app behaves as intended before connecting to the backend):

await remoteConfig.setDefaults(const {
  "example_param_1": 42,
  "example_param_2": 3.14159,
  "example_param_3": true,
  "example_param_4": "Hello, world!",
});

• Never store confidential data in Remote Config keys or values — they can be accessed by end users.
• Use type-specific getters: getBool(), getDouble(), getInt(), getString().
• Define parameters with the same names in the Firebase console as those in your app.
• Group related parameters with common prefixes (e.g., login_timeout, login_attempts_max).

3. Fetching and Activating

await remoteConfig.fetchAndActivate();

• Use fetchAndActivate() to fetch and apply values in a single call.
• Alternatively, call fetch() then activate() separately to control when values take effect.
• Activate fetched values at appropriate times (e.g., app start) for a smooth user experience.
• Check remoteConfig.lastFetchStatus to determine if the fetch was successful, failed, or throttled.
• Handle fetch failures gracefully by falling back to default values.

4. Real-time Updates

remoteConfig.onConfigUpdated.listen((event) async {
  await remoteConfig.activate();
  // Use the new config values here
});

• Real-time Remote Config is not available for Web.
• Update your UI state when new configuration values are activated.
• Ensure real-time updates don't disrupt the user experience.

5. Throttling and Performance

• Fetch calls are throttled if an app fetches too frequently.
• Default minimum fetch interval in production: 12 hours.
• For development, use a shorter interval — but only in debug builds:

await remoteConfig.setConfigSettings(RemoteConfigSettings(
  fetchTimeout: const Duration(minutes: 1),
  minimumFetchInterval: const Duration(minutes: 5),
));

• Be mindful of service-side quota limits with a large user base.

6. Testing and Debugging

• Use conditional values in the Firebase console to test configurations without new app deployments.
• Implement A/B testing with different parameter values for different user segments.
• Test your app with both default and remote values.
• Verify graceful handling of configuration changes at runtime.
• Test offline behavior to ensure proper fallback to defaults.

References

• Firebase Remote Config Flutter documentation