uPort Android SDK

Identity for your Android dApps.

This is a preview version of the uPort android SDK. Many intended features are still missing, stay tuned.

Installation

This SDK is currently being distributed using jitpack

In your main build.gradle file, add:

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
        ...
    }
}

In your application build.gradle:

def uport_sdk_version = "v0.0.2"
dependencies {
    ...
    // core SDK
    implementation "com.github.uport-project.uport-android-sdk:sdk:$uport_sdk_version"
    // required for meta transaction fueling
    implementation "com.github.uport-project.uport-android-sdk:fuelingservice:$uport_sdk_version"
}

Usage

This preview version requires that the SDK be configured with a functional IFuelTokenProvider There is a FuelTokenProvider implementation provided in the fuelingservice library

Configure uPort in your Application class

override fun onCreate() {
    
    val config = Uport.Configuration()
                    .setApplicationContext(this)
                    .setFuelTokenProvider( FuelTokenProvider(this, "<your dApp MNID>"))
    
    Uport.initialize(config)
}

defaultAccount

This preview version of the SDK allows creation of a single account that can be accessed by the nullable defaultAccount field in the Uport object.

Uport.defaultAccount?.address // Returns the mnid address of the default account
Uport.defaultAccount?.proxyAddress // Returns the hex address of the default account
Uport.defaultAccount?.network // Returns the network id of the default account

//returns the ETH balance of the deviceAddress (measured in wei)
Uport.defaultAccount?.getBalance() { err, balance ->
    // do something with balance or respond to err
}

//or as a coroutine:
val balanceInWei = Uport.defaultAccount?.getBalance()

Account Creation

if (Uport.defaultAccount == null) {
    
    Uport.createAccount(network = Networks.rinkeby) { err, account ->
            // update UI to reflect the existence of a defaultAccount
    }
    
}

In case the app gets killed during the account creation process, the createAccount method will try to resume the process where it left off. It can be instructed to start from scratch, but that may cost additional fuel.

Ethereum interaction

uPort SDK lets you create, sign, and submit Ethereum transactions on behalf of your users.

This preview uses metaTransactions for defaultAccount

//send value
val destination: String = "0x010101...."
val amountInWei = BigInteger.valueOf(1_000_000_000)

Uport.defaultAccount?.send(activity, destination, amountInWei) { err, txHash ->
  // Update UI to indicate that transaction has been sent and is confirming
  Networks.rinkeby.awaitConfirmation(txHash) { err, receipt ->
    // Complete operation in UX
  }
}


//`send` can also be used in coroutines

//call contract
val contractAddress = "0x010101..."
val data = <ABI encoded method call>

val txHash = Uport.defaultAccount?.send(activity, contractAddress, data)
val receipt = Networks.rinkeby.awaitConfirmation(txHash)

Dependencies

This library uses kethereum for a lot of ethereum related work.

The smart-contract encoding is generated using bivrost-kotlin

Private key management is done using uport-android-signer

Currently there is a transient dependency on spongycastle but that may be removed when pure kotlin implementations of the required cryptographic primitives become available.