Building an open-source crypto and fiat converter with Next.js 14

I recently built a small open-source project called NexCurrency – a fiat and crypto converter built with Next.js 14, TypeScript, Tailwind CSS, and shadcn-style UI components. The goal was to create a clean system that can convert between: • fiat → fiat • fiat → crypto • crypto → fiat • crypto → crypto The tricky part was combining fiat and crypto APIs. Fiat APIs usually return pair-based exchange rates, while crypto APIs return USD prices per asset. To simplify this, the app normalizes both into a shared internal model using a usdPrice value. Conversions then become: amount * (from.usdPrice / to.usdPrice) This approach avoids needing direct pairs for every asset combination and keeps the system provider-agnostic. Tech stack: • Next.js 14 (App Router) • TypeScript • Tailwind CSS • Zod validation • CoinGecko API (crypto prices) • Frankfurter API (fiat rates) GitHub repository: https://github.com/zvspany/NexCurrency I'd really appreciate any feedback on the architecture, UI/UX, or overall