Future Finance
Forecast your future account balance, day by day
Overview
A single-user financial forecaster. It projects your future account balance from a manually-maintained current balance, using recurring and once-off income and expenses, public holidays, business-day adjustments, and per-instance overrides.
The forecast engine is pure and deterministic, with no React and no database access, so the same code runs on the server and again in the browser. The dashboard recomputes instantly as you change an assumption.
Key features
- Deterministic forecast engine
- A pure module with no React or database dependencies, running identically on the server and in the browser so the dashboard recomputes instantly.
- Replay from the last known balance
- Every forecast replays from the date the balance was last updated forward to the visible window, so future months reflect every event since.
- Recurring and once-off particulars
- Income and expenses can recur or happen once, with per-instance overrides when a single occurrence differs from its pattern.
- Holidays and business-day adjustment
- Payments landing on a holiday or weekend shift according to the rule you choose, so the projection matches what the bank will actually do.
- Debt Buster
- Model a payoff plan across multiple debts, compare snowball against avalanche against a custom order, and see the interest and timeline each approach costs you.
- End-to-end type safety
- tRPC and shared zod schemas mean the client form and the server procedure validate against the same definition.
Screenshots
Dashboard: Answers the question you actually have: will I make it to payday? See the lowest point your balance reaches before it gets there, so you can move something now instead of finding out on the day.
Particulars: Set up your pay, rent, subscriptions and one-off bills once, and the forecast keeps itself current. Change a single occurrence when life differs from the pattern, without rewriting the pattern.
Debt Buster: Decide where an extra $400 a month should go. Compare paying the smallest debt first against the highest interest first, and see what each choice costs you in interest and how much sooner you are debt free.
Spending: Find out where the money actually goes each month, and how much is left over once it has gone, so you know what you have to redirect before you commit it.
Holidays: Import your state's public holidays so the forecast pays you and bills you on the days the bank really will, instead of being quietly wrong for a week around Easter and Christmas.
Dashboard on mobile: Check where you stand from the checkout queue. The summary is the first thing you see, and once you scroll ahead to a date that matters, a pinned bar keeps telling you what the balance will be on the day you are reading.
Stack
- Next.js
- TypeScript
- tRPC
- Prisma
- PostgreSQL
- Tailwind CSS
- Vitest