BudgetMaster

Money app for your phone: quick add, budgets that start on payday, reports and spaces shared with a partner.

Runs on my home server, so it may be offline now and then (for example during a power or internet outage).

BudgetMaster home with what is left of the monthly budget and the spending pace

About the project

A personal finance app I started in 2024 on Next.js and MongoDB. Later I rebuilt it from scratch on TanStack Start and PostgreSQL, and it now runs as a live demo on my home server.

It answers three questions: where did my money go, how much can I still spend this month, and what is coming up. A couple can keep a shared household space while personal money stays personal. The demo gives every visitor a private copy of 14 months of sample data.

What you can try

Quick add in a few seconds, or a typed line like "coffee 3.20 cash yesterday"; known payees fill in their category
Budgets per category with a month that can start on payday, rollover and a spending pace chart
Recurring payments, savings goals, split receipts and a 90-day balance forecast
Shared spaces with roles, who paid what and settle up, changes pushed live to other devices
Bank statement import from CSV with a review step, duplicate detection and undo
Reports: cash flow, net worth, spending calendar, monthly report and a year in review
Wallets in their own currencies; totals, budgets and reports convert them at ECB exchange rates
Optional help from Claude, off until you switch it on: read a receipt photo or a PDF bank statement, suggest a category, answer questions about your money or sum up a month
Bill reminders as push notifications and an optional weekly email summary
A log of who changed what, with restore for deleted transactions and undo for changes
Export everything as JSON or CSV, or delete the account
English, Hungarian and Slovak, installable on a phone, light and dark mode

Under the hood

Server functions with Zod validation and a membership check on every request; amounts stored as integer minor units
Better Auth with passkeys, two-step sign-in and social sign-in; strict Content Security Policy and CSRF checks
Sign-in attempts rate-limited with the limits kept in the database; invites are sent only from verified accounts, at most 10 an hour
Changes reach other devices and members through Server-Sent Events; server-only modules keep the database driver out of the browser bundle
Playwright tests with axe accessibility checks on desktop and mobile; Docker image built in GitHub Actions and deployed with nightly database backups

Changelog

Rebuilt from scratch: Next.js and MongoDB replaced by TanStack Start and PostgreSQL with Drizzle
Custom JWT auth replaced by Better Auth, Redux by TanStack Query and Zustand
daisyUI replaced by Tailwind CSS 4 and shadcn/ui with a new design

When: 2024 – 2026
Type: Personal
Versions: TanStack Start 1.169
React 19.2
PostgreSQL 18
Tailwind CSS 4
TypeScript 6
Stack: TanStack Start
React
TypeScript
PostgreSQL
Drizzle ORM
Better Auth
TanStack Query
Zustand
Tailwind CSS
shadcn/ui
Recharts
Paraglide
Playwright
Docker

Gallery

Quick add with a typed line that filled in the amount and payee — Quick add: type "coffee 3.20 cash yesterday" and the form fills itself; known payees bring their category.

Activity list grouped by day with search and filters — Activity: every transaction grouped by day, with search and filters that stay in the link.

Budgets page with the spending pace chart and category budgets — Budgets: the spending pace against last month and a limit per category, warned before it runs out.

Reports with income and spending per month — Reports: a year of income and spending, money flow, net worth, trends and a spending calendar.

Recurring payments with their schedule and yearly cost — Recurring payments record themselves on their due date; subscriptions show what they cost a year.

Home in Hungarian with the monthly budget and spending pace — The whole app also runs in Hungarian and Slovak, with local number and date formats.