DevView

A Kotlin Multiplatform library that adds an in-app developer overlay to Android and iOS apps. The overlay hosts pluggable modules for feature flags, analytics inspection, and network mocking.

Full documentation: worldline.github.io/devview

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Requirements

• Android minSdk 26
• iOS 16+
• Kotlin 2.x
• Compose Multiplatform

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Installation

DevView is published to Maven Central. Add the modules you need to your shared KMP module:

// build.gradle.kts (shared / commonMain)
dependencies {
    implementation("com.worldline.devview:devview:<version>")           // core — always required

    implementation("com.worldline.devview:devview-featureflip:<version>")   // feature flags
    implementation("com.worldline.devview:devview-analytics:<version>")     // analytics inspector
    implementation("com.worldline.devview:devview-networkmock:<version>")   // network mock UI

    // Ktor plugin only (no UI — lightweight alternative for network-layer integration)
    implementation("com.worldline.devview:devview-networkmock-core:<version>")
    implementation("com.worldline.devview:devview-networkmock-ktor:<version>")
}

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Quick Setup

1. Register modules and render the overlay

@Composable
fun MyApp() {
    val modules = rememberModules {
        module(module = FeatureFlip)
        module(module = Analytics())
        module(
            module = NetworkMock(
                resourceLoader = { path -> Res.readBytes(path = path) }
            )
        )
    }

    var devViewOpen by remember { mutableStateOf(false) }

    // Your existing app content
    AppContent(onOpenDevView = { devViewOpen = true })

    // DevView overlay
    DevView(
        devViewIsOpen = devViewOpen,
        closeDevView = { devViewOpen = false },
        modules = modules
    )
}

rememberModules handles DataStore initialisation and module setup automatically. DevView renders as a transparent overlay on top of your content.

2. Feature Flags

Define flags and provide the handler to the composition:

val featureHandler = rememberFeatureHandler(
    features = listOf(
        Feature.LocalFeature(name = "dark_mode", description = "Enable dark theme", isEnabled = false),
        Feature.RemoteFeature(
            name = "new_checkout",
            description = "New checkout experience",
            defaultRemoteValue = remoteConfig.getBoolean("new_checkout"),
            state = FeatureState.REMOTE
        )
    )
)

CompositionLocalProvider(LocalFeatureHandler provides featureHandler) {
    // Read flags anywhere in the tree
    val isDarkMode by LocalFeatureHandler.current.isFeatureEnabled("dark_mode")
}

3. Analytics

Forward events to AnalyticsLogger from your existing analytics layer:

AnalyticsLogger.log(
    AnalyticsLog(
        tag = "purchase_completed",
        screenClass = "CheckoutScreen",
        timestamp = Clock.System.now().toEpochMilliseconds(),
        type = AnalyticsLogCategory.Ecommerce.Purchase
    )
)

Provide the log list above DevView:

CompositionLocalProvider(LocalAnalytics provides AnalyticsLogger.logs) { … }

4. Network Mocking (Ktor)

Place your mock config at composeResources/files/networkmocks/mocks.json and install the plugin:

val client = HttpClient(OkHttp) {
    install(NetworkMockPlugin)
}

rememberModules { } must be called (and composed) before the first HTTP request reaches this client.

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Available Modules

Module	Artifact	Description
Core	devview	DevView composable + rememberModules DSL. Required by all modules.
FeatureFlip	devview-featureflip	Runtime feature flag management with Compose UI. Supports local and remote-config flags with local overrides.
Analytics	devview-analytics	Real-time analytics event inspector with filtering by type, category, and time range.
NetworkMock (UI)	devview-networkmock	Full mock management UI: enable/disable endpoints, switch responses, preview and diff mock payloads.
NetworkMock Core	devview-networkmock-core	Mock engine: JSON config parsing, request matching, DataStore state. No UI dependency.
NetworkMock Ktor	devview-networkmock-ktor	Ktor HttpClientPlugin that intercepts requests and returns mock responses.

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License

Apache License 2.0