- Type
- Web app
- Runs on
- Any modern browser
- Get it
- In development
- Price
- €2.99/mo Subscription
How it’s built
Private source
The source code is private. How it’s built is still described below.
- Web app
- Next.js
- React
- TypeScript
- Tailwind CSS
- PWA
- API
- NestJS
- Prisma
- PostgreSQL
- Money & security
- decimal.js
- Argon2id
Architecture
Three repositories: a public website, the authenticated web app, and an API that owns the financial domain. The app talks to the API server-side; the website never talks to it at all.
A pure financial engine
Every calculation — Safe to Spend, recurrence schedules, money → time, tax reserves, goal arrival dates — lives in a domain layer with no framework, database or I/O, and is unit tested formula by formula. Money is a decimal with a currency, never a floating-point number.
Facts first, words second
A Guardian line is built from values the engine has already calculated — how many days a mission is ahead or behind, and against which date — and the Guardian stays silent below a significance threshold or when you switch it off. Tests cover both. Moving every remark into the engine, with memory and cooldowns, is on the roadmap.