💰 Finance & Invoicing · $15/mo

Can I vibe code YNAB?

Zero-based budgeting: give every dollar a job.

🟡Kinda — with gapsest. a weekend

The budgeting engine — categories, monthly assignment, rollover, the four rules — is genuinely buildable and fun to personalize. The two hard parts are bank sync (you'll need a data aggregator with its own fees and setup, or manual CSV imports) and the method itself, which YNAB has refined into education, defaults, and guardrails. If you're happy importing CSVs weekly, a personal version is deeply satisfying.

The one-shot prompt
Build a zero-based budgeting app in the YNAB style for personal use. Model: accounts, category groups > categories, monthly budgets where I assign available money to categories, unspent amounts roll forward, overspending flags red. Transactions import from bank CSV exports (build a mapping step for column names) with auto-categorization rules I can edit (payee contains X → category Y). Views: budget grid by month, account register, and a dashboard (net worth line, spending by category, average daily spend). Keep all data in a hosted Postgres, make the category math server-side and unit-tested. Next.js, deployable to Vercel.
Paste into Claude Code, Codex, or your agent of choice — then steer. Learn the moves in Prompt Engineering.
What you build

A zero-based budget app: accounts, category groups, monthly assignment with rollover, transaction import from bank CSVs with rule-based auto-categorization, and an age-of-money style dashboard.

What you give up
  • Automatic bank sync (or you pay/configure an aggregator yourself)
  • Mobile apps with on-the-go entry and shared budgets
  • A decade of methodology polish, education, and community
  • Reconciliation edge cases the real thing handles silently
Why people still pay

Bank sync friction is the moat: the day manual import annoys you is the day the subscription looks cheap. The method's hand-holding keeps people budgeting.

bank syncmethodology
Related
Actually build it

A prompt is the first move, not the whole game. Course 01 teaches you to take a prompt like this one to a shipped, working app — reviewing, correcting, and steering the agent the whole way.

Start Course 01 →