re:Money: Personal Financial Management Re-imagined with AI
My 2026 resolution: ditch spreadsheets for managing my finances. Over the holidays, I built re:Money—a complete financial tracking solution—to dive deep on AI-assisted development and the Renaissance Developer. The shocking part? I wrote only less than 30 lines of code. Everything else was generated by AI with provided architecture reference, short prompts and a my technical guidance. This article chronicles the journey of building re:Money with Kiro with AI in the loop, as our coding partner.
Why I Built re:Money
I've always been frustrated with personal finance software. Every app I tried felt like it was built for someone else—too complicated, too simple, or locked behind paywalls and subscriptions. Worse, they all failed to integrate directly with my bank accounts, which never sat right with me.
But the real breaking point came when I realized I was spending more time fighting with these tools than actually managing my money. I'd import a CSV from my bank, and the categories would be wrong. I'd want to see a specific report, but the app wouldn't let me. I'd need to track something slightly different, and there was no way to customize it. I was adapting my workflow to fit the software, when it should have been the other way around.
So I decided to build something different. Something that would:
- Give me complete control over my financial data—no third-party services, no data mining, just my data in my own database
- Work the way I think, not force me into someone else's idea of how finances should be managed
- Be flexible enough to grow with my needs, whether that's tracking personal expenses today or managing business finances tomorrow
- Stay simple at its core, but powerful when I need it to be
- Be truly mine—open source, customizable, and free from vendor lock-in
I also wanted to explore something bigger: what if software could be generative? What if, instead of being stuck with what the developer thought you needed, you could just tell an AI assistant "add this feature" and it would do it on the fly? With tools like Kiro and the Model Context Protocol, that's not science fiction anymore—it's how I work with re:Money every day.
Overview
re:Money is a modern, open-source financial tracking application designed to help individuals and small businesses manage their banking transactions, track expenses, and gain insights into their financial activities. Built on cutting-edge technology with a focus on performance, scalability, and ease of use, re:Money provides a comprehensive solution for personal finance management.
What makes re:Money unique is its generative software approach: the entire codebase is designed to be easily customizable using AI-powered development tools and coding assistants. Whether you need to add custom features, integrate with specific banking systems, or adapt the application to your unique workflow, re:Money's clean architecture and comprehensive documentation make it the perfect foundation for building your personalized financial management solution; check this demo with re:Money in action importing a CSV from Bank of America with a typical web interface:
Generative Open-source Software
re:Money is a proof of concept for a new paradigm: Generative Open-Source Software, this approach reimagines how we build, distribute and use software by combining AI development tools like Kiro with open-source applications specifically architected for AI-assisted evolution and renascence.
The innovation lies in the architecture: re:Money includes comprehensive steering guides, architecture patterns, and extension instructions that serve as context for AI models. This enables developers to describe features in natural language while the AI generates code that seamlessly follows the project's conventions and best practices.
Traditional open-source software offers two paths: use it as-is or fork and manually modify it. Generative open-source software introduces a third way—a living foundation that continuously evolves with your needs through AI-assisted development. You retain all the benefits of open source (transparency, control, no vendor lock-in) while gaining the rapid customization capabilities of AI code generation.
This is the essence of Renascence Computing: software that's reborn and reshaped for each user's unique requirements, making technology truly adaptive rather than prescriptive. Check the demo using Kiro chat to change re:Money and notice that we are changing it in run-time; we are using Kiro as the coding agent but we can ship solutions with their own changing agent:
How I built re:Money
To build re:Money, beside my 30 or less lines of code, I use three things:
- Kiro IDE / CLI
- A simple Java backend reference architectrure using Quarkus, DynamoDB and REST APIs called "PiggyBank"
- Short prompts using Vibe coding instead of spec-driven.
The PiggyBank reference app defines this JSON to store transactions (expenses / incomings / transfer) from bank accounts, credit card or investments:
JSON
{"id": "550e8400-e29b-41d4-a716-446655440000","timestamp": 1733702400000,"accountID": "ACC001","description": "Grocery shopping at Whole Foods","category": "Food & Dining","amount": -85.42,"balance": 2314.58,"date": "2025-01-15T14:30"}
And the simple REST API provides methods for operations like:
-
POST /entryResource- Create new entry
-
GET /entryResource/findAll- Retrieve all entries
-
GET /entryResource/findById/{id}- Get specific entry
-
DELETE /entryResource/id/{id}- Delete entry
I learnt that providing a reference architecture to the model is very efficient and Kiro performed pretty well with simple prompts instead of complex .md files with endless list of tasks; to create the user-interface the prompt was simple like this:
"Create a web user-interface using pure HTML and JS with Qute template framework that allows CRUD operation and filter by dates and category"
And after 3 weeks of development, re:Money is now a full-stack financial management platform that combines:
- Robust Backend: A high-performance Quarkus-based REST API built with Java 21
- Deploy Anywhere: You can self-host re:Money in your owm machine or take advantage of the cloud-native architecture that leverages AWS DynamoDB for scalable, reliable data storage and containers or Lambdas for hosting the app
- Modern Web Interface: Intuitive UI for managing expenses, viewing reports, and importing data
- AI Integration: Natural language chat interface powered by Model Context Protocol (MCP)
- Flexible Data Import: Support for CSV imports from various banking institutions
- Open Source: Complete source code available for customization and extension
- Generative Software Ready: Designed to work seamlessly with AI development tools like Kiro providing specific .md files for Kiro Powers and also skills.sh
The application is designed to be both powerful for advanced users and accessible for those new to financial tracking. More importantly, it's built to be your application—easily customizable to match your specific needs.
Core Philosophy
re:Money was built with several key principles in mind:
1. Simplicity First
Financial tracking shouldn't be complicated. re:Money provides straightforward ways to record transactions, categorize expenses, and view your financial data without overwhelming complexity.
2. Data Ownership
Your financial data belongs to you. re:Money can be deployed locally for development or in your own AWS environment, giving you complete control over your sensitive financial information.
3. Run and deploy anywhere
re:Money is primary designed to be self-hosted but you can leverages AWS services for scalability and reliability. Whether you're tracking personal expenses or managing multiple business accounts, the application scales seamlessly to meet your needs.
4. Extensibility
The Model Context Protocol (MCP) integration allows re:Money to be extended with AI-powered tools and integrations, making it a platform for innovation in personal finance management.
5. Open Source & Customizable
re:Money is fully open source, giving you complete access to the codebase. Combined with AI-powered development tools, you can easily customize, extend, and adapt the application to your specific needs—creating a truly personalized financial management solution.
Key Features
Financial Entry Management
At the heart of re:Money is a comprehensive transaction management system:
- Transaction Recording: Capture every financial transaction with details including amount, category, description, and date
- Account Tracking: Manage multiple accounts (checking, savings, credit cards) with automatic balance calculations
- Category Organization: Organize transactions into customizable categories for better expense tracking
Flexible Querying
re:Money provides multiple ways to access your financial data:
- Account-Based Queries: View all transactions for a specific account
- Category Filtering: See all expenses in a particular category
- Date Range Analysis: Analyze spending patterns over custom time periods
- Multi-Criteria Filtering: Combine account, category, and date filters for precise queries
- Sorting Options: View transactions in ascending or descending order by date
Data Import and Export
Managing financial data shouldn't require manual entry:
- CSV Import: Bulk import transactions from bank statements and credit card exports
- Format Detection: Automatic detection of CSV formats from various financial institutions
- Multi-File Upload: Import multiple CSV files simultaneously
- Account Mapping: Associate imported transactions with specific accounts
Web-Based Interface
A modern, pure and simple HTML + JS, responsive web interface provides:
- Expense Dashboard: Overview of your financial activity
- Category Management: View and organize expense categories
- Account Overview: Monitor all your accounts in one place
- Pivot Tables: Analyze spending patterns across categories and time periods
- CSV Import UI: User-friendly interface for importing bank statements
AI-Powered Chat Interface
Interact with your financial data using natural language:
- Conversational Queries: Ask questions like "Show me my expenses for this month"
- MCP Integration: Powered by Model Context Protocol for extensible AI capabilities
- Context-Aware Responses: Get intelligent insights based on your transaction history
Check the following demo using re:Money MCP Server and Kiro chat to automatic categorize the imported expenses:
Technical Architecture
Technology Stack
re:Money is built on a modern, enterprise-grade technology stack:
- Quarkus 3.17.4: Modern Java framework optimized for containers
- Java 21: Latest LTS version with modern language features
- DynamoDB: NoSQL database for high-performance, scalable data storage. You can run a lightweigth local dynamodb and take full control over the database or use AWS DynamoDB for secure data storage and sharing
- RESTful API: Standard HTTP/JSON APIs for easy integration
- Maven: Industry-standard build and dependency management
Deployment Options
re:Money offers flexible deployment options:
- Local Development: Run with local DynamoDB for testing, development and local use
- AWS Cloud: Deploy to AWS with managed AWS DynamoDB and AWS Lambda for production use
- Native Executable: Compile to native binary with GraalVM for ultra-fast startup and minimal memory footprint
- Container-Ready: Docker support for containerized deployments
Conclusion
re:Money represents a new paradigm in personal finance software: generative software that adapts to you, rather than forcing you to adapt to it. By combining:
- Open source transparency and freedom
- Self-hosted or Cloud-native performance and scalability
- AI-powered easy customization with coding assistants
- MCP integration for extensibility
- Clean architecture for maintainability
re:Money is not just a financial tracking application—it's a platform for building your perfect financial management solution.
Whether you use it as-is or customize it extensively, re:Money puts you in control of both your financial data and the software that manages it. In an era where most financial software is closed-source and inflexible, re:Money offers a refreshing alternative: a tool that grows and evolves with your needs.
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