CDK Kotlin

Kotlin/Android bindings for the Cashu Development Kit (CDK).

Requirements

• Android SDK with Build-Tools for API level 24 or higher
• Android NDK (for building from source)
• Rust toolchain with cargo (for building from source)

Environment Setup

Before building, set up the following environment variables:

export ANDROID_SDK_ROOT=~/Library/Android/sdk
export ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT/ndk/<your-ndk-version>

Replace <your-ndk-version> with your installed NDK version.

Installation

From Maven Repository

Add the dependency to your app's build.gradle.kts:

dependencies {
    implementation("org.cashudevkit:cdk-kotlin:0.14.3-rc.2")
}

Building from Source

1. Set up environment variables (see Environment Setup section above)
2. Set up and build:

   just setup
   just install-deps
   just build-android
   just publish-local

Usage

import org.cashudevkit.*
import kotlinx.coroutines.runBlocking

// Create an in-memory database
val database = runBlocking { WalletSqliteDatabase.newInMemory() }

// Configure the wallet
val config = WalletConfig(targetProofCount = 10u)
val mnemonic = generateMnemonic()

// Create wallet instance
val wallet = Wallet(
    mintUrl = "https://testmint.cashu.space",
    unit = CurrencyUnit.Sat,
    mnemonic = mnemonic,
    db = database,
    config = config
)

// Create a mint quote for 1000 sats
val amount = Amount(value = 1000UL)
val mintQuote = wallet.mintQuote(
    amount = amount,
    description = "Test mint quote"
)

// Check wallet balance
val balance = wallet.totalBalance()
println("Wallet balance: ${balance.value} sats")

// Clean up resources
wallet.close()
database.close()

Architecture Support

The library includes native binaries for the following Android architectures:

• arm64-v8a (64-bit ARM)
• armeabi-v7a (32-bit ARM)
• x86 (32-bit Intel/AMD)
• x86_64 (64-bit Intel/AMD)

Development

Generating Bindings

To regenerate Kotlin bindings from the CDK FFI:

just generate

This updates the auto-generated cdk_ffi.kt file with the latest bindings.

Running Tests

just test

Publishing Setup

For maintainers publishing to Maven Central, see CENTRAL_PORTAL_SETUP.md for detailed instructions on setting up Central Portal credentials.

License

This project is licensed under the MIT License.