runanywhere-minimal (Kotlin / Android)

A single-Activity Android app — one button, one text view — that streams one LLM completion. It is the contributor test harness for the Kotlin SDK: "does my C++/SDK change still work?" — not a showcase app.

It is an Android app rather than a JVM console app because the Kotlin SDK ships as an Android library (com.android.library) and its JNI core needs an Android Context and a real device/emulator ABI.

How it consumes the SDK

settings.gradle.kts pulls bindings/kotlin in as a composite build (includeBuild + dependencySubstitution), so the app compiles against the SDK from local source with no AAR staging step:

com.runanywhere:runanywhere-kotlin        -> project ':runanywhere-kotlin'
com.runanywhere:runanywhere-core-llamacpp -> project ':runanywhere-kotlin:modules:runanywhere-core-llamacpp'

Those coordinates are placeholders that exist only to be substituted; nothing is ever resolved from a repository. Unlike the files("../libs/*.aar") approach the full consumer app used before it moved to RunanywhereAI/runanywhere-android, this also brings the SDK's transitive runtime deps (coroutines, OkHttp, Wire) automatically, so the app declares none of them — and there is no AAR staging step to re-run after an SDK edit.

Prerequisites

The SDK's gradle.properties sets runanywhere.useLocalNatives=true, so the build wants the commons JNI .so files staged under bindings/kotlin/src/main/jniLibs/ and the backend module's modules/runanywhere-core-llamacpp/src/main/jniLibs/. If they are already present the build reuses them; if not, it shells out to the (slow) native build:

bash

# From the repo root — only needed when the .so files are missing or stale.
./scripts/build/build-core-android.sh

You also need local.properties with sdk.dir (Android Studio writes it; it is gitignored):

bash

echo "sdk.dir=$HOME/Library/Android/sdk" > examples/kotlin/minimal/local.properties

Run

bash

cd examples/kotlin/minimal

# Build + install + launch on a connected arm64 device/emulator
./gradlew :app:installDebug
adb shell am start -n com.runanywhere.minimal/.MainActivity

# Or just compile (fastest gate after an SDK change)
./gradlew :app:compileDebugKotlin

Tap Generate. The first run downloads the model, so give it a minute and watch adb logcat.

What it exercises

Step	API
Backend registration	`LlamaCPP.register()`
SDK bring-up	`RunAnywhere.initialize(context = this)`
Catalog entry	`RunAnywhere.models.register(ModelRegistration.url(...))`
Streaming generation	`RunAnywhere.llm.generateStream(prompt, LlmOptions(...))`

initialize is single-phase; there is no completeServicesInitialization() call to make. Download and load are automatic — passing LlmOptions.model is enough. The catalog is not auto-seeded, though: an unknown id is rejected before generation, so the one models.register call is required. To try a different model, change MODEL_ID/MODEL_URL in MainActivity.kt (the canonical ids and URLs live in apps/rcli/src/catalog/catalog.cpp).

Deliberately absent: Compose, a design system, model catalogs, navigation.

Note on the Kotlin version pin

build.gradle.kts applies org.jetbrains.kotlin.plugin.serialization 2.4.0 even though nothing here is @Serializable. AGP 9 supplies Kotlin itself (applying kotlin.android is a hard error now) and its bundled compiler is 2.2.0, which cannot read the SDK's 2.4.0 metadata. Putting a 2.4.0 Kotlin compiler plugin on the buildscript classpath pins the built-in compiler to 2.4.0 — the same trick bindings/kotlin itself uses.