CAOS
Filing taxes is learned by doing it wrong on a real return. CAOS is a trainer where you can get it wrong safely: a game on top, and an accurate tax engine underneath.
33
Prisma models
2
Tax regimes
3
Assessment years
The story
01 · THE PROBLEM
Nobody practises filing.
Students and new filers meet slabs, HRA, capital gains and surcharge for the first time on a live return. There's no safe place to make the mistakes that teach the rules.
02 · THE ENGINE
A tax engine, not a mock.
It computes tax under both regimes for AY 2024-25, 2025-26 and 2026-27: slabs, HRA, capital gains, surcharge, cess and the 87A rebate. Each attempt is scored and returned as a PDF feedback report.
03 · THE DATA
Thirty-three models, one source of truth.
33 Prisma models on PostgreSQL, with JWT auth and refresh-token rotation. A FastAPI ML service sits alongside, and Jest tests cover the engine.
04 · THE GAME
XP, streaks, leaderboards, and GST.
Gamification keeps people practising. A GST module adds input-tax-credit reconciliation, the same ground I cover in my day job at Electrocom.
How it's built
Every box is a real part of the system. The dots are data moving through it.
Built with
- Next.js 15
- Express
- TypeScript
- Prisma
- PostgreSQL
- FastAPI
- Jest
- Docker