Cashu Wallet

Native Cashu ecash wallets for iOS and Android.

Cashu is Bitcoin-backed ecash: a mint issues bearer tokens against sats deposited over Lightning, and payments between wallets are private by design — the mint does not learn who pays whom. Cashu Wallet wraps that model in a first-class native app on each platform — SwiftUI on iOS, Jetpack Compose on Android — with the same surfaces, copy, and behavior on both.

iOS on the first row, Android on the second — same journey on both platforms:

Onboarding	Wallet	Receive	Send

The full capture set for both platforms — onboarding through settings — lives in docs/screenshots/. All shots show a test wallet funded from the public Testnut mint; the balances are not real sats.

Features

• Ecash — hold sats as Cashu tokens; send and receive them as QR codes or copyable strings, without touching a Lightning channel.
• Lightning — fund the wallet and pay invoices through the mint, with BOLT11 invoices and BOLT12 offers.
• On-chain Bitcoin — receive to and send from mints that support it.
• Cashu Requests (NUT-18) — publish a reusable, address-shaped payment request that senders pay over Nostr relays, without leaking your mint or balance to anyone watching a single endpoint.
• NFC contactless — tap-to-pay ecash between devices.
• Locked ecash (P2PK) — lock a send to the recipient's key so only they can redeem it.
• Multi-mint — add mints by URL or QR, discover public mints, and keep per-mint balances visible.
• Nostr Wallet Connect — let other apps spend from the wallet with scoped permissions.
• Backup & restore — BIP-39 seed phrase backup and restore, plus an App Lock behind the platform's biometrics.

Repository layout

• ios/ — SwiftUI app, Xcode project, unit + UI tests, helper scripts. Targets iOS 18+.
• android/ — Kotlin / Jetpack Compose app and Gradle project. minSdk 26, targetSdk 36.
• docs/product/ — shared product, design, and copy contracts both apps implement. Platform notes live in docs/ios/ and docs/android/.
• CI/ — local mint infrastructure for integration tests: Nutshell and CDK mints running a FakeWallet Lightning backend, so end-to-end payment flows run without a real Lightning node.

Both apps are built on the Cashu Dev Kit (CDK) through its native FFI bindings.

Building

iOS (requires Xcode with the iOS 18+ SDK):

cd ios
xcodebuild -project CashuWallet.xcodeproj \
  -scheme CashuWallet \
  -destination 'platform=iOS Simulator,name=iPhone 17 Pro' \
  build

Android (requires JDK 17 and an Android SDK; point local.properties or ANDROID_HOME at it):

cd android
./gradlew --no-daemon :app:assembleDebug

Testing

Unit tests:

# iOS
cd ios && xcodebuild test -project CashuWallet.xcodeproj -scheme CashuWallet \
  -destination 'platform=iOS Simulator,name=iPhone 17 Pro' \
  -only-testing:CashuWalletTests

# Android
cd android && ./gradlew --no-daemon :app:testDebugUnitTest

Integration tests run the apps against real mint implementations started locally — see CI/README.md for the full setup:

./CI/setup-nutshell.sh && ./CI/start-nutshell.sh
./CI/setup-cdk.sh && ./CI/start-cdk.sh

License

MIT