a2ui-kmp

Google's Agent-to-UI renderer for Jetpack Compose (A2UI) on Kotlin Multiplatform: the same library and API on Android, desktop (JVM) and iOS. On Android you get Google's own artifacts; for desktop and iOS it is built from Google's sources.

Sponsored by LittlePress.AI. Not affiliated with Google.

Versions match Google's releases: 1.0.0-alpha02 is built from Google's 1.0.0-alpha02 (see source/UPSTREAM and CHANGELOG.md). We will keep following them until Google publishes A2UI for Kotlin Multiplatform itself. The API is Google's, in the same androidx.a2ui.* packages; common code differs from Android code in two places only (see Platforms).

Add the artifacts to your version catalog, with the Google and Maven Central repositories:

# gradle/libs.versions.toml
[versions]
a2ui = "1.0.0-alpha02"

[libraries]
a2ui-material3-kmp = { module = "ai.littlepress.a2ui:material3-a2ui", version.ref = "a2ui" }
a2ui-compose-ui-kmp = { module = "ai.littlepress.a2ui:compose-ui", version.ref = "a2ui" }
a2ui-compose-runtime-kmp = { module = "ai.littlepress.a2ui:compose-runtime", version.ref = "a2ui" }
a2ui-model-kmp = { module = "ai.littlepress.a2ui:a2ui-model", version.ref = "a2ui" }
a2ui-engine-kmp = { module = "ai.littlepress.a2ui:a2ui-engine", version.ref = "a2ui" }
a2ui-compose-ui-testing-kmp = { module = "ai.littlepress.a2ui:compose-ui-testing", version.ref = "a2ui" }

// settings.gradle.kts
dependencyResolutionManagement {
    repositories {
        google()
        mavenCentral()
    }
}

// build.gradle.kts
kotlin {
    sourceSets.commonMain.dependencies {
        // 1. The basic catalog drawn with Material 3, and everything it needs
        implementation(libs.a2ui.material3.kmp)
        // 2. Or, to draw your own components: the renderer and catalog API without Material 3
        // implementation(libs.a2ui.compose.ui.kmp)

        // 3. Only the Compose runtime of the renderer (state, data binding), to build your own renderer
        // implementation(libs.a2ui.compose.runtime.kmp)
        // 4. Only the protocol model, without Compose
        // implementation(libs.a2ui.model.kmp)
        // 5. The engine that processes messages, for renderer developers (no Compose)
        // implementation(libs.a2ui.engine.kmp)
    }
    sourceSets.commonTest.dependencies {
        // 6. Testing APIs for your catalog's components
        // implementation(libs.a2ui.compose.ui.testing.kmp)
    }
}

All artifacts have the same version:

• Android: ai.littlepress.a2ui:<artifact> resolves to Google's artifact of the same version, the way JetBrains publishes its multiplatform Jetpack libraries. Android apps run Google's code.
• Desktop (JVM) and iOS: Google's sources, compiled for these platforms. Where they use Android or JDK APIs, they call our equivalents, built to behave as Android does. Besides running upstream's own unit and UI tests on desktop, the build checks plural rules, number, currency and date formatting, JSON parsing and resource locale selection on desktop and iOS against results recorded on an Android device. The few remaining differences are listed in the changelog.
• Common code compiles against the same API as on Android, with two differences:
  • java.util.Locale in two interfaces is ai.littlepress.a2ui.compat.java.util.Locale (on the JVM, java.util.Locale itself).
  • A2uiBasicCatalogV1.Functions(context) takes an android.content.Context on Android and ai.littlepress.a2ui.compat.android.content.Context() on desktop and iOS, which opens URLs with the platform. Call it from platform code.

What our artifacts require is the least your project ends up with: Gradle raises Compose and the Kotlin standard library to it, and a Kotlin compiler cannot read iOS artifacts with a newer klib ABI than its own. These are the versions each package is built and tested with:

• a2ui-model, a2ui-engine, compose-runtime, compose-ui, compose-ui-testing: Kotlin 2.3 and Compose Multiplatform 1.12.
• material3-a2ui: Kotlin 2.4 and Compose Multiplatform 1.13.0-beta01, because upstream uses Material 3 APIs that Compose Multiplatform has only from 1.13. It moves to the stable 1.13 when that is released.
• Android, as the official artifacts require: compileSdk 37.1 (37 for a2ui-model and a2ui-engine); from compose-runtime up, Jetpack Compose 1.13.0-alpha03, and for material3-a2ui also Material 3 1.5.0-alpha28.

samples/ is a small desktop and iOS app: the basic catalog drawn with Material 3, and a catalog of the app's own components. Its Form tab, a surface from the agent, and what goes back to the agent when you press Book:

Desktop	iOS

How the repository is organised, how a new upstream release is synced, and how releases are made: DEVELOPMENT.md.

Apache License 2.0. See LICENSE and NOTICE.