Sats Stack

A local-first, Bitcoin-native personal finance app built with Flutter. No cloud. No accounts. No tracking.

Track your fiat spending and your Bitcoin stack in the same place — understand what you're spending, what you're saving, and how much you're losing to inflation.

Features

Transactions

• Manual transaction entry with categories and notes
• CSV import with automatic bank format detection and auto-categorisation
• xpub wallet import (BIP44/49/84) — syncs via Mempool.space Esplora
• Edit and delete transactions
• Recurring transactions (daily / weekly / monthly / yearly)
• Transaction search and filter (by keyword, category, source)
• Historical BTC price recorded per transaction at time of import

Dashboard

• Monthly income / spending / surplus overview
• Fiat "leak rate" and inflation cost metrics
• Spending breakdown by category (bar chart)
• Per-wallet breakdown (when multiple wallets are active)
• AI monthly insight (requires Ollama — desktop)
• Month selector for historical browsing

Budgets

• Per-category monthly budgets with progress bars
• Sats opportunity cost display ("this category cost you X sats")
• Overspend notifications (≥ 80% warning, > 100% alert)

Bitcoin Stack

• All-time cumulative sats chart with time filters (1M / 3M / 6M / 1Y / All)
• DCA simulator — model future stack growth
• Stack goal with progress bar, projected completion date, and average sats/month
• Goal-reached notification

Analytics

• Spending pie chart by category
• 6-month income vs spending trend chart
• Year-to-date summary
• CSV export of monthly spending vs budget

Settings

• Dark / Light / System theme
• Currency: USD, GBP, EUR, CAD, AUD
• Custom Mempool/Esplora server (for privacy — routes all wallet sync and price data through your own node)
• AI — Ollama server configuration (desktop)
• SQLite database export and import
• Custom spending categories with colour and icon picker
• Data routing banner showing exactly which servers are contacted

Privacy

By default the app contacts mempool.space (wallet sync, BTC price) and CoinGecko (price fallback). If you configure a self-hosted Mempool/Esplora server, all data is routed through it exclusively — no third-party servers are contacted.

All data is stored locally in a SQLite database via Drift. Nothing is ever uploaded.

AI Features

AI features use Ollama running locally (desktop) or on a remote server (mobile — coming soon). No data leaves your machine unless you point it at an external Ollama instance.

Supported: macOS, Windows, Linux. iOS/Android support with a remote server URL is in development.

Tech Stack

Concern	Package
Database	Drift (SQLite, type-safe, reactive)
Navigation	go_router 16.x
Charts	fl_chart
Bitcoin crypto	pointycastle, bs58check, bech32
Notifications	flutter_local_notifications
File I/O	file_picker, path_provider

No state management library (Provider/Riverpod/Bloc) — services are plain Dart singletons initialized at startup, with ValueNotifier for reactive UI updates.

Getting Started

Prerequisites

• Flutter SDK ≥ 3.7
• For macOS: Xcode
• For iOS: Xcode + CocoaPods (brew install cocoapods)
• For AI features: Ollama with at least one model pulled (e.g. ollama pull llama3.2)

Run

# macOS
flutter run -d macos

# iOS simulator
flutter run -d "iPhone 16e"

# List available devices
flutter devices

After changing the database schema

dart run build_runner build --delete-conflicting-outputs

iOS note

The iOS Podfile requires platform :ios, '12.0' and use_modular_headers! inside the target 'Runner' block. These are already set — if you see CocoaPods errors about modular headers, ensure both lines are present in ios/Podfile.

Project Structure

lib/
  core/
    database/        # Drift schema, tables, migrations
    models/          # Plain data classes (DashboardData, WalletSummary, etc.)
    services/        # Business logic (BudgetService, XpubService, OllamaService, etc.)
  features/
    dashboard/       # Dashboard screen + widgets
    transactions/    # Transaction list, add/edit sheets
    budgets/         # Budget cards + set budget sheet
    stack/           # Stack chart, DCA simulator, goal card
    ai_chat/         # Ollama chat screen (desktop)
    analytics/       # Analytics screen (charts + CSV export)
    settings/        # Settings screen + categories sheet
    onboarding/      # 3-page onboarding flow
  shared/
    constants/       # AppConstants (settings keys, defaults)
    theme/           # AppColors, ThemeData
    utils/           # CurrencyUtils, PlatformUtils

License

GPL-3.0