Kotlin, Android, and Java

The Kotlin SDK is the default client stack for JVM and Android applications. It lives under kotlin/ in the Iroha repository and is split by platform so portable code does not acquire Android dependencies.

Modules

Artifact	Type	Use
org.hyperledger.iroha.sdk:core-jvm	JAR	Pure Kotlin/JVM Norito, data model, crypto, transaction, Torii, and protocol code
org.hyperledger.iroha.sdk:client-android	AAR	Android keystore, device telemetry, and JNI-backed client integrations
org.hyperledger.iroha.sdk:offline-wallet-android	AAR	Android offline-wallet transports and integration built on client-android

The artifacts are not yet published to Maven Central. Build and publish them locally from the pinned Iroha source revision:

cd kotlin
./gradlew publishToMavenLocal

Then select only the artifact your application needs:

repositories {
    mavenLocal()
}

dependencies {
    implementation("org.hyperledger.iroha.sdk:core-jvm:0.1.0")
    // Android client features:
    // implementation("org.hyperledger.iroha.sdk:client-android:0.1.0")
    // Android offline-wallet features:
    // implementation("org.hyperledger.iroha.sdk:offline-wallet-android:0.1.0")
}

core-jvm contains no Android dependencies. Keep Android client and keystore code in client-android, and use offline-wallet-android for Android-only offline-wallet and JNI flows.

Kotlin and Java Compatibility

The public API is Kotlin-first and provides Java interop where JVM callers need it. Equivalent changes are mirrored in the corresponding java/ implementation. New Android integrations should start with the Kotlin artifacts above.

All Kotlin modules enforce JDK 8 API compatibility at compile time with -Xjdk-release=8, even though the build toolchain itself uses JDK 21. Do not use JDK 9+ APIs in SDK code.

Build and Test

Run the portable JVM tests:

cd kotlin
./gradlew :core-jvm:test --console=plain

Build the Android artifacts:

./gradlew :client-android:assembleRelease \
  :offline-wallet-android:assembleRelease --quiet

Current Coverage

The Kotlin SDK includes:

• Norito encoding and decoding
• canonical account and asset address handling
• transaction building, signing, and offline envelopes
• Torii HTTP, WebSocket, and SSE clients
• multisignature, subscription, SoraFS, Nexus, and Connect models
• Android keystore and device telemetry integrations
• Android offline QR, Nearby, and NFC transports

See the Kotlin SDK README for module-specific APIs and exact build commands.