ant-mobile-android

Autonomi's Android reference app — external-signer paid uploads over WalletConnect. A Compose app that exercises the Autonomi SDK end-to-end: pick a file, preview the storage cost, pay from the user's own wallet (the app never holds a key), upload, and round-trip it back via Download.

Mirrors the iOS reference, ant-mobile-ios, and is the canonical worked example for ant-sdk/docs/mobile-external-signer.md.

What it does

Four tabs:

• Uploads — pick a file; shows a fast sampled cost preview (estimateFileCost) while it prepares the real quote (prepareFileUpload), then a confirm sheet. On approve it runs the external-signer paid flow (paymentTransactions → sign each tx via the connected wallet → waitForReceipt → finalizeUpload/finalizeUploadMerkle with live progress), handling both the wave and merkle payment shapes.
• Downloads — paste a data-map address to stream content back to a file (downloadPublicToFile, with progress).
• Wallet — connect a self-custody wallet via Reown AppKit (WalletConnect); shows address, chain, and ANT/ETH balances.
• Settings — a Developer section to point the app at a devnet host.

All ABI encoding, receipt polling, and the merkle-winner lookup live in the SDK — the app builds no calldata itself. (waitForReceipt / merkleWinnerPoolHash / networkInfo are SDK free functions; only paymentTransactions / prepare* / finalize* are Client methods.)

Prerequisites

• Android Studio or a command-line Android toolchain:
  • brew install --cask android-commandlinetools
  • JDK 17: brew install openjdk@17 (export JAVA_HOME=/opt/homebrew/opt/openjdk@17)
  • Android SDK platform 34 + build-tools 34.0.0 (+ an arm64-v8a emulator image if not using a physical device). Set ANDROID_HOME (e.g. ~/Library/Android/sdk).
  • Build with the bundled wrapper (./gradlew, Gradle 8.9 — required for AGP 8.5.2). When a change doesn't seem to take, use ./gradlew clean assembleDebug (a "1s BUILD SUCCESSFUL" can skip compileDebugKotlin).
• A physical device or emulator, and — for the paid flow — a WalletConnect wallet (e.g. MetaMask) funded on the target chain (Arbitrum Sepolia for a test devnet).

Autonomi SDK dependency

Consumes the published SDK from the ant-maven GitHub Pages Maven repo — implementation("com.autonomi:ant-android:0.0.7") (repo declared in settings.gradle.kts). Bump the version to adopt a newer SDK release; no local AAR needed. The SDK pulls JNA + kotlinx-coroutines-core transitively.

Connecting to a devnet

The app connects from a devnet manifest. Set Settings → Developer → devnet host to the host serving the manifest API, e.g. 192.168.0.62:8088; the app fetches http://<host>/api/devnet-manifest.json over HTTP and polls /api/info for liveness.

• Physical device on the same LAN (recommended, and how e2e is validated): point the devnet host at the machine's LAN IP. Cross-device LAN devnet works with the released SDK (needs ant-android ≥ 0.0.7) — the SDK's connectFromDevnetManifest* auto-detects a LAN vs loopback manifest and binds 0.0.0.0 when a non-loopback bootstrap addr is present. No upstream ant-node change is required.
• Emulator: 127.0.0.1 inside the emulator is the emulator, not the host, and the NAT does not reliably establish QUIC to loopback-bound devnet services — prefer a physical device on the LAN. (Historical NAT-rewrite recipe using 10.0.2.2 is no longer the supported path.)

To stand up a LAN/Sepolia devnet, see ant-lan-devnet (ant-devnet --host <ip> --serve-port 8088).

Build & run

export JAVA_HOME=/opt/homebrew/opt/openjdk@17
export ANDROID_HOME=$HOME/Library/Android/sdk
./gradlew :app:installDebug
adb shell am start -n com.autonomi.examples.antdemo/.MainActivity

WalletConnect setup

Get a project id from https://dashboard.reown.com and set reownProjectId in MainActivity.kt (Reown project ids are public client identifiers — safe to ship). Connect from the Wallet tab; approve in the wallet app. For a test devnet, fund the wallet on Arbitrum Sepolia (chain 421614). If a wallet session gets into a bad state, clearing app data resets the WalletConnect session/SQLite stores.

Caveats

• This is a devnet reference app; the devnet-manifest connect path is test-only. Production bootstrap discovery/config differ.
• The app plants HOME via a libc setenv shim before the first FFI call (AntFfiBootstrap.kt) because ant-core reads $HOME and otherwise aborts with HomeDirNotFound. Workaround pending an explicit data-dir FFI arg.
• The bundled signing config is debug for one-tap install/run. Don't ship to Play with this.