The application is a subscription management platform built with Next.js, Prisma, and Better Auth. It allows users to track recurring payments, set up multi-channel notifications (email, push, webhook, ntfy, Discord, Slack), view financial reports, and manage account settings. The system supports multi-currency, timezone awareness, and can be self-hosted via Docker or used as a SaaS with Paddle for payment processing. Architecturally, it follows a client-server model with Next.js App Router, separating concerns into components, lib utilities, API routes, and server actions. The data layer uses Prisma ORM with PostgreSQL, and authentication is handled via Better Auth with multiple providers. Background notification processing is implemented through a cron job hitting the `/api/cron/` endpoint. Key reusable components include a multi-channel notification system, internationalization hooks for language management, and a timezone-aware datetime picker. These components demonstrate encapsulation, minimal internal dependencies, and patterns that could be extracted for use in other projects.
Akaunting is a self-hosted accounting and invoicing platform for small businesses and freelancers. It manages invoices, bills, banking transactions, transfers, reconciliations, multi-currency, multi-tax, recurring documents, and financial reports. It includes a customer portal for invoice viewing and payment, and supports multi-company, multi-user with role-based permissions. The system is highly internationalized with 40+ language locales. The architecture is built on a custom PHP framework (Illuminate) that extends Laravel conventions. It uses an event-driven architecture with domain events, listeners, and a job queue for async processing. The frontend combines Blade templates, Vue.js components, and Livewire for interactivity. Multi-tenancy is achieved through company scoping via a global query scope. The system is extensible via a module system with an app store, and includes a CLI for maintenance tasks. Key entry points include the installation wizard (controllers under Install/), authentication flows, and core CRUD controllers for sales, purchases, banking, and settings. Data flows typically involve controllers dispatching jobs that emit events, which listeners handle to update related entities, send notifications, or trigger side effects. Reports use a filter/group/rows event system for extensibility. Import/export is handled via Excel with multi-sheet support. External dependencies include PHP 8.1+, Node 18-20, and a database (MariaDB, MySQL, PostgreSQL, SQLite). It uses Laravel Mix for asset compilation, integrates with payment gateways, email services, and error trackers (Sentry, Bugsnag), and relies on a module marketplace at api.akaunting.com.
Firefly III is a self-hosted personal finance management application built on the Laravel PHP framework. It provides comprehensive double-entry bookkeeping with support for multiple currencies, accounts, budgets, categories, bills, piggy banks, recurring transactions, and rules. The system exposes both a full web UI using Blade templates and Alpine.js (with legacy jQuery components) and a RESTful JSON API (v1) for programmatic access. Key features include transaction splitting, budget limits, auto-budgeting, rule-based transaction processing, exchange rate management, webhook integration, multi-user with group administration, and detailed reporting with charts. The codebase follows a repository pattern with interfaces, uses events and listeners for side effects, and includes a substantial set of artisan commands for maintenance, upgrades, and data corrections.
Invoice Ninja is a full-featured open-source invoicing and billing platform designed for small to medium businesses. It handles the complete lifecycle of invoices, quotes, credits, purchase orders, payments, and expenses. The system supports multi-tenant SaaS and self-hosted deployments with per-company database isolation, and integrates with over 20 payment gateways (Stripe, PayPal, Mollie, GoCardless, etc.). It provides client and vendor portals for self-service, along with extensive reporting, CSV export, and e-invoicing capabilities (Peppol, Verifactu, France e-reporting). The application follows a monolithic MVC architecture built on a custom PHP framework (Illuminate) similar to Laravel. It uses an event-driven architecture with domain events and listeners for side effects (email, webhooks, activity logging). Background jobs are queued for async processing. The frontend uses Blade templates, Livewire components, and a separate React app for some admin panels. The API is RESTful with OpenAPI documentation. Key entry points are HTTP controllers under app/Http/Controllers, with request validation classes. Core data flows involve creating entities through factories, persisting via repositories, and triggering events that listeners handle. Payment flows go through abstract payment drivers that encapsulate gateway-specific logic. The system also includes extensive reporting, CSV export, and e-invoicing (Peppol, Verifactu, France e-reporting). External dependencies include a relational database (MySQL/PostgreSQL), Redis for caching and queues, Elasticsearch for search, and various third-party APIs for payment processing, tax calculation (ZipTax), bank integration (Nordigen, Yodlee), email delivery (Mailgun, Postmark, Brevo), and e-invoicing gateways (Storecove, Qvalia).