# How to Vibe Code Your Own Lunch Money (and Stop Paying for It)

> Delightfully simple personal finance & budgeting

- Site: https://lunchmoney.app
- Category: Finance
- Verdict: **Solid side project** (72/100 vibecodeable)
- Estimated effort: 2-3 weeks part-time

## Verdict

Build a solid side project clone of Lunch Money's core budgeting and multi-currency engine, though banking with Plaid introduces production compliance and sandbox friction.

You can replicate the core dashboard, rules engine, manual CSV imports, and multi-currency calculators in a few weeks of focused vibecoding. However, connecting real bank feeds via Plaid requires wading through compliance approvals, webhook retry queues, and token refreshing edge cases that will test your patience.

### What you can't replicate

- Lunch Money's established indie brand and lifetime price-lock guarantee
- Production-ready Plaid financial institution verification status without a live business entity

## What it does

Web-first personal finance and budgeting software featuring multi-currency support, crypto tracking, transaction imports, and automated rules.

### Core features

- Manual and CSV/PDF transaction imports
- Plaid API bank account syncing
- Flexible budgeting and recurring items engine
- Multi-currency exchange rate conversion and historical data
- Cryptocurrency portfolio tracking
- Rules automation engine for categorizing transactions
- Net worth calculator and analytics dashboards
- Collaborative shared budgets

## The business

### Pricing

- Monthly Subscription: $10/mo — All product features included with a 30-day free trial.
- Annual Subscription: $100/yr — Sliding scale pay-what-you-want starting from $100/yr.

Founded 2019.
Team size: Solo creator + ~5 contractors.

## The hard parts

- Maintaining stable Plaid API ingest pipelines across international banking standards and handling rate limits
- Multi-currency accounting logic mapping historical daily exchange rates to exact transaction timestamps
- Building a performant rules and query engine that executes regex and custom splits across large relational datasets
- Securing sensitive financial records with proper AES-256 encryption at rest and ephemeral signed file attachments

## How to vibe code Lunch Money

### Prerequisites

- Node.js (free): Required for running the Next.js full-stack framework and package manager.
- GitHub (free): Source control and continuous deployment pipeline integration.
- Plaid Developer Account (free): Required to test bank syncing and transaction webhooks.

### Recommended AI tools

- Claude Code: Best-in-class agentic coding tool for scaffolding full-stack database schemas and complex financial calculation logic.
- Cursor: Ideal for fine-tuning React dashboard UI components, charts, and table utilities.

### Stack

- Frontend: Next.js with Tailwind CSS and shadcn/ui
- Backend: Next.js Server Actions and API Routes
- Database: Turso (libSQL/SQLite)
- Auth: better-auth
- Payments: None (personal use clone skips billing)
- Other: Plaid API for bank syncing, Resend for transactional emails

### Hosting

- Vercel (Hosting the Next.js full-stack frontend and serverless API endpoints): $0/mo (Hobby Tier)
- Turso (Serverless SQLite edge database storage for user transactions and rules): $0/mo (Free Tier)

### Build guide

1. **Project Scaffolding & Database Schema** — Initialize the Next.js project with Tailwind CSS, configure Turso SQLite via Drizzle ORM, and set up better-auth for user authentication.

```
Create a new Next.js project using TypeScript and Tailwind CSS. Integrate Turso (libSQL) via Drizzle ORM and set up better-auth for secure user authentication with email and password. Define the database schema for users, accounts, transactions, categories, tags, and rules. Ensure all tables include proper foreign key constraints, indexes on transaction dates and account IDs, and user isolation. Create clean migration scripts and test database connection locally.
```

2. **Transaction Management & CSV Importer** — Build the transaction data grid view along with a robust CSV parser to import bank statement exports.

```
Build a responsive transaction dashboard view using shadcn/ui data tables with sorting, filtering, and pagination. Implement a CSV import wizard that parses uploaded bank statement files, maps columns dynamically (date, payee, amount, currency), detects duplicates based on transaction fingerprint hashes, and bulk-inserts them into the transactions table. Add manual transaction logging modals with category and tag assignment.
```

3. **Plaid Bank Integration** — Integrate Plaid Link to exchange public tokens, store encrypted access tokens, and ingest live banking transactions.

```
Implement Plaid Link integration using the Plaid Node SDK. Create backend API routes to exchange public tokens for access tokens, securely store tokens in the database, and fetch synced transactions and account balances. Build a background sync endpoint that pulls transaction updates via Plaid webhooks, handling cursor pagination and deduplication securely.
```

4. **Multi-Currency & Exchange Rate Engine** — Add multi-currency support with historical daily exchange rate conversion capabilities.

```
Build a multi-currency accounting utility that supports over 160 currencies. Integrate a public exchange rate API to fetch daily historical rates and cache them in the database. Implement conversion logic that maps any transaction amount to the user's configured home currency based on the exact transaction date, and display converted totals across dashboards and category views.
```

5. **Rules Engine & Categorization Automation** — Develop an automated rules engine that evaluates incoming transactions against custom criteria and applies categories.

```
Develop a rules engine backend service and UI. Users should be able to create rule conditions (e.g., if payee contains 'Starbucks', set category to 'Coffee'). Write a background function that automatically evaluates newly imported or synced transactions against active rules in priority order, updating categories and tags on the fly. Provide a dry-run test tool to preview rule matches against existing transactions.
```

6. **Budgeting, Analytics, & Net Worth Dashboard** — Create spending analytics charts, category budgeting limits, and a net worth calculation overview.

```
Build analytics charts and stats dashboards using Recharts to visualize monthly spending trends, income vs. expense ratios, and category breakdowns. Implement monthly budgeting views where users set spending caps per category with progress bars. Build a net worth calculation module that aggregates asset accounts (checking, savings, crypto) minus liability accounts (credit cards, loans) over historical time intervals.
```

### Cost vs paying

**Starting costs (one-time):**

- Domain name registration: $12 one-time
- Total: ~$12 one-time

**Ongoing costs (monthly):**

- Vercel & Turso Hobby tiers: $0/mo
- Total: $0/mo

- Paying for the SaaS instead: $10/mo
- Build time: 35-50 hours
- AI tool credits: $20 (Claude Pro / Cursor)
- Break-even: 1 month

## Sources

- [Lunch Money Homepage](https://lunchmoney.app)
- [Lunch Money Pricing Page](https://lunchmoney.app/pricing)
- [Lunch Money Security Page](https://lunchmoney.app/security)