SpendSense

Overview

SpendSense is a personal budgeting application built with .NET MAUI Blazor Hybrid, designed to run across iOS, Android, Mac Catalyst, and Windows from a single codebase. The app takes a local-first approach with SQLite for offline data storage, while using Aspire for multi-device development orchestration.

The app provides comprehensive budget tracking with intelligent features like predictive overspend warnings, category auto-suggestion, and automated recurring transaction generation — all running on-device without requiring a backend.

Features

Transaction Management — record income, expenses, and savings with categories, currencies, and notes
Recurring Transactions — auto-generates transactions on app launch (salary, subscriptions, rent)
Monthly Budgets — per-category spending limits with copy-to-next-month templates
Savings Goals — targets with auto-calculated progress from linked category transactions
Dashboard — monthly summary with pie chart, spending breakdown, overspend warnings, and month-over-month comparison
Spending Trends — dedicated page with configurable line and bar charts over 3/6/12 months
Predictive Warnings — linear projection alerts when spending pace will exceed budget
Category Auto-Suggestion — learns from transaction history to pre-select categories
Local Notifications — budget threshold alerts (80%/100%) and goal milestones (50%/100%)
Privacy Mode — hide all monetary values with a single toggle
Dark Mode — persisted theme preference
Income Attribution — configurable setting for whether income funds the current or next month’s budget

Tech Stack

Framework: .NET 10 / C# with MAUI Blazor Hybrid

UI Library: MudBlazor 9

Database: SQLite via Entity Framework Core (local-first, offline-capable)

Orchestration: Aspire with dev tunnels for multi-device debugging

Notifications: Plugin.LocalNotification

Architecture: Repository pattern, SaveChanges interceptors for timestamps, Preferences API for settings

Architecture Decisions

Local-first with SQLite — works fully offline, no server dependency, data stays on device
Repository pattern — thin layer over DbContext for testability and separation of concerns
Enum-to-string storage — enums stored as readable strings in SQLite for debuggability
Recurring transaction generation — runs synchronously on app startup after migrations
Notification deduplication — uses Preferences to track notified thresholds, preventing repeat alerts across app restarts

Project Structure

SpendSense/
├── App/SpendSense/              # MAUI Blazor app
│   ├── Common/
│   │   ├── Data/                # DbContext, repositories, interceptors
│   │   ├── Models/              # Entity models and enums
│   │   ├── Interfaces/          # Shared interfaces
│   │   └── Services/            # SettingsService, RecurringTransactionGenerator, NotificationService
│   ├── Components/
│   │   ├── Layout/              # MainLayout, NavMenu
│   │   └── Pages/               # All page components (CRUD, Dashboard, Settings, Trends)
│   ├── Migrations/              # EF Core migrations
│   └── MauiProgram.cs           # App startup and DI
├── Infra/
│   ├── SpendSense.AppHost/      # Aspire orchestration
│   └── SpendSense.ServiceDefaults/ # Shared service configuration
└── ROADMAP.md                   # Future plans

Future Roadmap