Featured

Featured is a type-safe, reactive feature-flag and configuration management library for Kotlin Multiplatform — Android, iOS (via SKIE), and JVM.

Highlights

• Type-safe flags — declared in the Gradle DSL, accessed via generated typed extensions on ConfigValues. No string keys, no unchecked casts.
• Dead-code elimination in release builds — a flag with default = false makes the guarded code unreachable. The Gradle plugin emits R8 -assumevalues rules (Android/JVM) and an xcconfig with DISABLE_<FLAG> Swift compilation conditions (iOS), so the respective compilers physically strip disabled branches from release binaries.
• Reactive — every value is observable via Flow; Compose and SwiftUI/Combine integrations included.
• Multiple providers — DataStore, SharedPreferences, NSUserDefaults, JavaPreferences, Firebase Remote Config, ConfigCat, or a custom one.
• Debug UI — a ready-made Compose screen for overriding flags at runtime.

Platform stability

Platform	Status
Android	Stable
iOS (SKIE / DCE)	Preview
JVM	Preview

Preview means the platform is functional but its public API may change in minor releases without a major version bump. Stable platforms follow Semantic Versioning.

Quick example

// build.gradle.kts — declare the flag
plugins {
    id("dev.androidbroadcast.featured") version "<version>"
}

dependencies {
    implementation(platform("dev.androidbroadcast.featured:featured-bom:<version>"))
    implementation("dev.androidbroadcast.featured:featured-core")
    implementation("dev.androidbroadcast.featured:featured-datastore-provider")
}

featured {
    localFlags {
        boolean("new_checkout", default = false) {
            description = "Enable the new checkout flow"
        }
    }
}

// Application.kt — wire up ConfigValues once
val dataStore = PreferenceDataStoreFactory.create { context.dataStoreFile("feature_flags.preferences_pb") }

val configValues = ConfigValues(
    localProvider = DataStoreConfigValueProvider(dataStore),
)

// Read the generated extension anywhere
val isEnabled: Boolean = configValues.isNewCheckoutEnabled()

Customizing generated code

By default the plugin generates internal objects named GeneratedLocalFlags<ModuleSuffix> / GeneratedRemoteFlags<ModuleSuffix> in the dev.androidbroadcast.featured.generated package. The generation { } block overrides the package, class names, and visibility — module-wide in featured { } and per section inside localFlags { } / remoteFlags { } (section values win):

import dev.androidbroadcast.featured.gradle.FeaturedVisibility

featured {
    generation {                                  // module-wide defaults
        packageName = "com.example.checkout.flags"
        visibility = FeaturedVisibility.INTERNAL
    }
    localFlags {
        generation {                              // overrides for local flags only
            className = "CheckoutLocalFlags"      // exact name, no module suffix appended
            visibility = FeaturedVisibility.PUBLIC
        }
        boolean("new_checkout", default = false)
    }
}

The generated .kt file is named after the custom class name. With a custom name the module-suffix-based JVM-name uniqueness no longer applies — make sure two modules don't generate the same package + class name. ProGuard/R8 -assumevalues rules and the iOS const-val files automatically follow the local section's effective package, so release-build dead-code elimination keeps working with custom packages.

Multi-module pattern

In a multi-module app, construct one ConfigValues per feature module plus one debug aggregator, all sharing the same LocalConfigValueProvider:

// Construct one ConfigValues per feature module + one debug aggregator, all over a shared provider
val sharedLocal: LocalConfigValueProvider = defaultLocalProvider(applicationContext)

val checkoutConfig = ConfigValues(localProvider = sharedLocal)
val promotionsConfig = ConfigValues(localProvider = sharedLocal)
val uiConfig = ConfigValues(localProvider = sharedLocal)

// Debug-only aggregator that the FeatureFlagsDebugScreen drives
val debugConfig = ConfigValues(localProvider = sharedLocal)

FeatureFlagsDebugScreen(
    configValues = debugConfig,
    registry = GeneratedFeaturedRegistry.all,
)

Each feature module owns its own ConfigValues and observes only its own flags (via public observe-bridge extensions). The generated GeneratedLocalFlagsX / GeneratedRemoteFlagsX objects are internal to their module — cross-module flag listing flows exclusively through GeneratedFeaturedRegistry.all, which is built from the per-module manifests by the aggregator plugin. The single source of truth for stored overrides is the shared LocalConfigValueProvider, so writes from any instance propagate to every other one through its reactive observe flow.

Documentation

Full documentation lives in the Wiki:

• Getting Started
• Installation
• Providers
• Release Optimization (DCE) — how flags get stripped from release binaries
• iOS Usage
• Best Practices

Contributing

See CONTRIBUTING.md.

Security

See SECURITY.md.

License

MIT — see LICENSE.