How I Made My Flutter App Modular with Multiple Flavors

In this post, I'll share how I structured a modular Flutter app with multiple build flavors—one of which required unique Android permissions and behavior. Managing configurations across environments while avoiding code duplication was a fun challenge.

Why Flavors?

We needed to support:

• A consumer-facing app (no advanced permissions)
• An internal tester/debug app (with elevated permissions)

Rather than clone the app or manually swap configs, flavors gave us clean separation and automation.

Flavor Setup

1. Defined flavors in build.gradle:

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productFlavors {
    consumer {
        dimension "app"
        applicationIdSuffix ".consumer"
    }
    internal {
        dimension "app"
        applicationIdSuffix ".internal"
    }
}

1. Used different AndroidManifest.xml files:

src/
├── consumer/
│   └── AndroidManifest.xml
├── internal/
│   └── AndroidManifest.xml

1. Flutter flavor entry points:

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flutter run --flavor consumer -t lib/main_consumer.dart
flutter run --flavor internal -t lib/main_internal.dart

Challenges

• Ensuring all shared code was kept outside flavor-specific files
• Avoiding duplication across manifests and Gradle configs

Tips

• Use conditional imports for flavor-specific logic
• Externalize secrets per flavor
• Automate build matrix via CI

Outcome

• Clean, maintainable codebase
• Fast switching between environments
• Fewer config bugs in production