Gas Sponsorship Demo — ZeroDev + Privy (Android)

A Jetpack Compose Android app demonstrating gasless smart account transactions using ZeroDev Omni SDK for ERC-4337 account abstraction and Privy for authentication + embedded wallet signing.

What it does

1. Login — User authenticates via email OTP (Privy)
2. Embedded wallet — Privy creates a secure embedded Ethereum wallet
3. Smart account — ZeroDev creates a Kernel v3.3 smart account with the Privy wallet as owner
4. Gas sponsorship — ZeroDev's paymaster sponsors all gas fees (user pays nothing)
5. Send transaction — Gasless UserOp from the smart account, confirmed on Sepolia

Setup

1. Set your credentials in gradle.properties:

   ZERODEV_PROJECT_ID=your-project-id
   PRIVY_APP_ID=your-privy-app-id
   PRIVY_CLIENT_ID=client-your-privy-client-id

2. Build and run:

   ./gradlew assembleDebug
   adb install app/build/outputs/apk/debug/app-debug.apk

   Or open in Android Studio and hit Run.

File structure

app/src/main/java/com/zerodev/demo/
├── DemoApplication.kt    # Application class, Privy SDK init
├── MainActivity.kt       # Entry point, Compose setup
├── PrivySigner.kt        # SignerImpl: Privy wallet → ZeroDev signer
├── WalletViewModel.kt    # Auth → wallet → smart account state machine
└── WalletApp.kt          # Compose UI (login, OTP, dashboard)

Dependencies

From Maven Central and Google:

• app.zerodev:zerodev-aa:0.0.1-alpha.5 — ERC-4337 smart account SDK
• io.privy:privy-core:0.9.2 — Auth + embedded wallets
• Jetpack Compose (BOM 2024.12.01)

Tested on

• Android 15 (API 35) — Pixel 8 emulator
• Android 16 (API 37) — Pixel 8 emulator (16KB page aligned)