Digital Asset Accounts Android SDK

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What you can do

• Approve operations with a passkey: run passkey enrollment and approval for Strong Customer Authentication (SCA) in a Kotlin application.
• Hold the authorization key for non-custodial accounts: the React Native SDK calls this SDK to create the end customer’s authorization key in hardware-backed key storage and sign with it. You don’t call these methods yourself. To build a non-custodial account integration, use the React Native SDK.

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Requirements

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Install

// settings.gradle.kts
dependencyResolutionManagement {
    repositories {
        google()
        mavenCentral()
        maven(System.getenv("DAA_ANDROID_MAVEN_URL")) {
            credentials {
                username = System.getenv("DAA_ANDROID_MAVEN_USERNAME")
                password = System.getenv("DAA_ANDROID_MAVEN_PASSWORD")
            }
        }
    }
}

// app/build.gradle.kts
dependencies {
    implementation("com.circle.daa:daa-android-sdk:0.6.0")
}

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Set up the callback

1. Choose an https callback URL on a domain that you control, such as https://app.example.com/sca/callback. The SDK refuses a URL that includes a port or an IP address, and can be up to 2,048 characters. Circle doesn’t accept custom schemes.
2. Register every exact callback URL that you use in Circle Hub, under Settings > Digital Asset Accounts > SCA. Register separately in sandbox and production.
3. Declare the SDK’s callback activity in your AndroidManifest.xml, with an intent filter for your callback URL:
   <activity
       android:name="com.circle.daa.sdk.sca.DaaScaCallbackActivity"
       android:exported="true"
       android:excludeFromRecents="true"
       android:taskAffinity=""
       android:theme="@android:style/Theme.Translucent.NoTitleBar">
       <intent-filter android:autoVerify="true">
           <action android:name="android.intent.action.VIEW" />
           <category android:name="android.intent.category.DEFAULT" />
           <category android:name="android.intent.category.BROWSABLE" />
           <data
               android:scheme="https"
               android:host="app.example.com"
               android:path="/sca/callback" />
       </intent-filter>
   </activity>
   
4. Serve https://<host>/.well-known/assetlinks.json with the delegate_permission/common.handle_all_urls relation. List the SHA-256 fingerprint of every key that signs your application, including the Play App Signing key and your debug key. Serve it over HTTPS, without redirects, with Content-Type: application/json.

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Initialize

import com.circle.daa.sdk.DaaEnvironment
import com.circle.daa.sdk.sca.DaaScaConfig

val scaConfig = DaaScaConfig(
    environment = DaaEnvironment.Sandbox,
    redirectUri = "https://app.example.com/sca/callback",
)

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Methods

class TransferActivity : ComponentActivity() {
    private val scaConfig = DaaScaConfig(
        DaaEnvironment.Sandbox,
        "https://app.example.com/sca/callback",
    )
    private var transferId: String? = null

    private val approve =
        registerForActivityResult(DaaScaApproveContract(scaConfig)) { result ->
            val transfer = transferId ?: return@registerForActivityResult
            transferId = null
            when (result) {
                // Send the response exactly as returned.
                is DaaScaResult.Completed -> backend.confirmTransfer(transfer, result.response)
                DaaScaResult.Cancelled -> showMessage("Transfer not approved. You can try again.")
                is DaaScaResult.Failed -> showScaFailure(result)
            }
        }

    fun onSendClicked(transfer: String) {
        backend.startTransfer(transfer) { frameToken ->
            transferId = transfer
            approve.launch(frameToken)
        }
    }
}

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Errors

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Versions