# QuickTax — Global Tax Calculator

> Take-home pay calculations for 67 countries. Hard-coded rules from official government sources. Deployable REST API included. Values are estimates, not financial advice.

QuickTax is a React SPA + Express API sharing a single TypeScript tax engine. 67 tax regimes across Europe, Americas, Asia, Middle East, Africa, Oceania, and territories.

## Pages

- [Home](/): Salary calculator with country selector, jurisdiction-aware fields, pay period toggle (annual/monthly/weekly/daily/hourly), shareable URLs, results breakdown.
- [Compare](/compare): Side-by-side comparison across any two of 67 countries.
- [For Sale](/for-sale): Acquisition details.

## Features

- 67 countries: Europe (23), Asia (15), Americas (8), Middle East & Africa (11), Oceania (2), Territories (8)
- Social insurance: FICA, NI, Sozialversicherung, CPF, NPS, NTA 2025 (NG), and more
- Custom deductions, dark mode, shareable URLs, employer cost toggle
- 82 Vitest unit tests covering all 67 countries

## API

Endpoints: GET /api/v1/health, GET /api/v1/countries, GET /api/v1/countries/:code/config, POST /api/v1/calculate

Security: API key auth, rate limiting (trust proxy configured), helmet security headers, Zod validation, body size limit 10KB.

## Technical

Frontend: React 18 + Vite 5 + TypeScript 5 + Tailwind CSS
Backend: Express 5 + TypeScript
Deploy: Vercel (SPA), Docker (API)