FiatLife

A privacy-first Android application for tracking your fiat finances. All data is stored encrypted via Nostr events on your personal relay and synced across devices. Attachments (bills, statements) are stored on a Blossom server.

Downloads

Official releases include the Android APK and Start9 server package:

Latest release

Platform	Package
Android	fiatlife-android-*.apk — sideload on Android 8+
Start9 (x86_64)	fiatlife_x86_64.s9pk — StartOS → Sideload

See packages/start9/README.md for aarch64 builds and server setup.

Features

Paycheck Calculator

• Configure hourly rate and standard hours (default 80 hours biweekly)
• Add overtime hours to see the impact on take-home pay
• Federal, state, county/local income tax withholding calculation
• FICA taxes (Social Security 6.2%, Medicare 1.45% + additional)
• Pre-tax deductions: medical/dental/vision insurance, HSA, FSA, traditional 401(k)
• Post-tax deductions: Roth 401(k), life insurance, AD&D, critical illness, disability
• Direct deposit allocation across multiple bank accounts
• Support for all US filing statuses and all 50 states

Bills Tracker

• Track household bills by category (mortgage, utilities, insurance, subscriptions, etc.)
• Multiple billing frequencies (weekly through annually)
• Monthly cost normalization across all frequencies
• Mark bills as paid/unpaid
• Attach PDF/image statements via Blossom server
• Category filtering and breakdown

Financial Goals

• Track goals: retirement, house down payment, emergency fund, vacation, car, etc.
• Progress tracking with visual indicators
• Monthly contribution projections and time-to-goal estimates
• Overall portfolio progress across all goals

Dashboard

• At-a-glance take-home pay and tax summary
• Monthly bill total and disposable income
• Top financial goals with progress
• Upcoming unpaid bills
• Nostr relay connection status

Privacy & Sync

• NIP-42: Automatic authentication with your personal relay
• NIP-44: All data encrypted with XChaCha20-Poly1305 before storage
• Kind 30078: Application-specific parameterized replaceable events
• Blossom Protocol: Decentralized file storage for bill attachments
• Local Room database cache for offline access
• Key generation and import

Tech Stack

• Language: Kotlin
• UI: Jetpack Compose with Material 3
• Architecture: MVVM + Clean Architecture
• DI: Hilt (Dagger)
• Local Storage: Room Database + DataStore Preferences
• Networking: OkHttp (WebSocket for Nostr, HTTP for Blossom)
• Crypto: secp256k1-kmp + Lazysodium (XChaCha20-Poly1305, HKDF)
• Serialization: kotlinx-serialization
• Image Loading: Coil

Project Structure

app/src/main/java/com/fiatlife/app/
├── data/
│   ├── blossom/          # Blossom blob storage client
│   ├── local/            # Room database, DAOs, entities
│   ├── nostr/            # Nostr client, NIP-42, NIP-44
│   └── repository/       # Data repositories
├── di/                   # Hilt dependency injection modules
├── domain/model/         # Domain models and business logic
├── ui/
│   ├── components/       # Reusable UI components
│   ├── navigation/       # Navigation graph and screen routes
│   ├── screens/          # Feature screens (dashboard, salary, bills, goals, settings)
│   ├── theme/            # Material 3 green theme
│   └── viewmodel/        # ViewModels for each feature
├── FiatLifeApp.kt        # Application class
└── MainActivity.kt       # Entry point

Building

Prerequisites

• Android Studio Hedgehog (2023.1.1) or newer
• JDK 17
• Android SDK 35

Local Build

# Clone the repository
git clone https://github.com/your-username/fiatlife.git
cd fiatlife

# Build debug APK
./gradlew assembleDebug

# Run tests
./gradlew testDebugUnitTest

# Install on connected device
./gradlew installDebug

CI/CD

The project includes a GitHub Actions workflow that:

1. On every push/PR: Builds debug APK, runs unit tests, runs lint
2. On push to main: Additionally builds a release APK

Artifacts (APKs, test reports, lint reports) are uploaded as workflow artifacts.

Release Signing

For signed release builds, add these secrets to your GitHub repository:

• SIGNING_KEY_ALIAS
• SIGNING_KEY_PASSWORD
• SIGNING_STORE_PASSWORD

Setup

1. Open the app and navigate to Settings
2. Generate a new Nostr key or import an existing one
3. Enter your personal relay URL (e.g., wss://relay.example.com)
4. Enter your Blossom server URL (e.g., https://blossom.example.com)
5. Tap Save & Connect

The app will authenticate with your relay via NIP-42 and begin syncing data.

Nostr Data Format

All data is stored as kind 30078 (application-specific) events with encrypted content:

Data Type	d-tag	Content
Salary Config	fiatlife/salary	NIP-44 encrypted JSON
Bill	fiatlife/bill/{uuid}	NIP-44 encrypted JSON
Financial Goal	fiatlife/goal/{uuid}	NIP-44 encrypted JSON

License

MIT