Tech stack - Contafy

Contafy is built with modern web technologies focused on performance, type safety, and developer experience.

Core framework

Next.js 16

Why Next.js: Full-stack React framework with built-in optimizations

App Router: File-based routing with nested layouts
Server Components: Zero-JavaScript-by-default rendering
Image optimization: Automatic image optimization
Font optimization: Built-in font loading (Geist)
TypeScript: First-class TypeScript support

Version: 16.1.1 Configuration: next.config.ts

const nextConfig: NextConfig = {
  async rewrites() {
    return [
      {
        source: '/backend/:path*',
        destination: `${process.env.NEXT_PUBLIC_API_URL}/:path*`,
      },
    ];
  },
};

React 19

Why React 19: Latest React with improved performance and DX

Concurrent features: Improved rendering performance
Server Components: Native server component support
Actions: Built-in form handling
Suspense: Better async component handling

Version: 19.2.3

TypeScript 5

Why TypeScript: Type safety and better IDE support Configuration: tsconfig.json:3-7

{
  "compilerOptions": {
    "strict": true,
    "target": "ES2017",
    "lib": ["dom", "dom.iterable", "esnext"],
    "paths": {
      "@/*": ["./*"]
    }
  }
}

Strict mode enabled: No any types, required null checks

Styling and UI

Tailwind CSS 4

Why Tailwind: Utility-first CSS framework for rapid UI development

JIT mode: Just-in-time compilation
Custom theme: Configured for dark mode
PostCSS integration: @tailwindcss/postcss

Version: ^4 (latest) Key utilities used:

Responsive design: md:, lg: breakpoints
Dark mode: Built-in dark mode support
Custom colors: Primary green theme
Spacing system: Consistent spacing scale

Radix UI

Why Radix: Unstyled, accessible UI primitives Packages used:

@radix-ui/react-dialog: Modal dialogs
@radix-ui/react-dropdown-menu: Dropdown menus
@radix-ui/react-select: Select inputs
@radix-ui/react-tabs: Tab navigation
@radix-ui/react-avatar: User avatars
@radix-ui/react-progress: Progress bars
@radix-ui/react-switch: Toggle switches
@radix-ui/react-radio-group: Radio buttons
@radix-ui/react-separator: Dividers
@radix-ui/react-label: Form labels
@radix-ui/react-slot: Component composition

Benefits:

WCAG compliant accessibility
Keyboard navigation support
Screen reader support
Full styling control

Shadcn/ui

Why Shadcn/ui: Pre-built components built on Radix UI Location: components/ui/ Components used:

button.tsx: Button variants
card.tsx: Card containers
table.tsx: Data tables
input.tsx: Form inputs
select.tsx: Select dropdowns
dialog.tsx: Modal dialogs
tabs.tsx: Tab navigation
badge.tsx: Status badges
progress.tsx: Progress bars
sonner.tsx: Toast notifications

Configuration: components.json

Lucide React

Why Lucide: Lightweight, customizable icons Version: ^0.562.0 Usage: Over 50 icons used throughout the app

import { Wallet, Check, FileText, BarChart3 } from 'lucide-react';

Motion

Why Motion: Animation library for React Version: ^12.27.1 Used for: Smooth transitions and micro-interactions

Data fetching and state

TanStack Query (React Query) 5

Why TanStack Query: Powerful data synchronization for React Version: ^5.90.19 Configuration: components/providers/ReactQueryProvider.tsx:11-24

const queryClient = new QueryClient({
  defaultOptions: {
    queries: {
      refetchOnWindowFocus: false,
      retry: 1,
    },
  },
});

Features used:

Query caching and invalidation
Automatic background refetching
Optimistic updates
Request deduplication
Loading and error states

Example usage:

const { data, isLoading } = useQuery({
  queryKey: ['expenses', profileId, mes, año],
  queryFn: () => getExpenses({ profileId, mes, año }),
});

React Hook Form

Why React Hook Form: Performant form handling Features:

Minimal re-renders
Built-in validation
TypeScript support
Easy integration with UI libraries

Zod

Why Zod: TypeScript-first schema validation Usage: Form validation with React Hook Form

const schema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
});

Data visualization

Recharts

Why Recharts: React charting library Version: ^3.6.0 Used for: Financial trend charts in dashboard Components used:

LineChart: Cash flow trends
BarChart: Monthly comparisons
AreaChart: Revenue visualization

Location: app/dashboard/components/FlowTrendChart.tsx

File processing and export

ExcelJS

Why ExcelJS: Excel file generation Version: ^4.4.0 Usage: Export financial reports to Excel format Implementation: lib/excel/

jsPDF

Why jsPDF: PDF generation in the browser Version: ^4.0.0 Usage: Export financial reports to PDF Implementation: lib/pdf/

jspdf-autotable

Plugin: Table generation for jsPDF Version: ^5.0.7

html2canvas-pro

Why html2canvas-pro: Convert HTML to canvas for PDF export Version: ^1.6.6

Utilities

Class Variance Authority (CVA)

Why CVA: Type-safe component variants Version: ^0.7.1 Used in: UI components for variant management

const buttonVariants = cva('base-styles', {
  variants: {
    variant: {
      default: 'bg-primary',
      outline: 'border',
    },
  },
});

clsx

Why clsx: Conditional className construction Version: ^2.1.1

clsx('base', condition && 'conditional', 'always');

tailwind-merge

Why tailwind-merge: Merge Tailwind classes without conflicts Version: ^3.4.0 Combined with clsx in lib/utils.ts:4-6:

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

Sonner

Why Sonner: Toast notifications for React Version: ^2.0.7 Usage: User feedback for actions

import { toast } from 'sonner';

toast.success('Factura guardada correctamente');
toast.error('Error al guardar factura');

Backend integration

Firebase

Why Firebase: Authentication and cloud services Version: ^12.9.0 Configuration: lib/firebase/config.ts Services used:

Authentication
Cloud Storage
Analytics

Logging

Pino

Why Pino: Fast JSON logger for Node.js Version: ^10.2.0 Configuration: lib/utils/logger.ts

pino-pretty

Dev tool: Pretty print Pino logs Version: ^13.1.3

Development tools

ESLint

Version: ^9 Configuration: eslint.config.mjs Extends:

eslint-config-next: Next.js recommended rules
eslint-config-prettier: Disable conflicting rules

Prettier

Version: ^3.8.1 Plugins:

prettier-plugin-tailwindcss: Sort Tailwind classes

Sharp

Image optimization: Next.js image processing Version: ^0.34.5

Package manager

pnpm

Why pnpm: Fast, disk-efficient package manager Required version: 8 or higher Workspace: Configured with pnpm-workspace.yaml Benefits:

Faster installs than npm/yarn
Saves disk space
Strict dependency resolution

Runtime requirements

Node.js

Required version: 20 or higher Why Node 20:

Native fetch support
Improved performance
Long-term support (LTS)

Environment variables

Required variables (.env.local):

# API Backend
NEXT_PUBLIC_API_URL=http://localhost:3001

# Frontend URLs
NEXT_PUBLIC_FRONTEND_URL=http://localhost:3000

# Admin route (optional)
ADMIN_DISCOUNT_ROUTE=internal/discount-management

Build output

Production build:

pnpm build

Generates optimized static and dynamic pages in .next/ Bundle analysis:

Server Components: No client JavaScript
Client Components: Code-split automatically
Images: WebP/AVIF with responsive srcset

See Architecture for how these technologies work together.

Architecture

Contributing

Documentation Index

​Core framework

​Next.js 16

​React 19

​TypeScript 5

​Styling and UI

​Tailwind CSS 4

​Radix UI

​Shadcn/ui

​Lucide React

​Motion

​Data fetching and state

​TanStack Query (React Query) 5

​React Hook Form

​Zod

​Data visualization

​Recharts

​File processing and export

​ExcelJS

​jsPDF

​jspdf-autotable

​html2canvas-pro

​Utilities

​Class Variance Authority (CVA)

​clsx

​tailwind-merge

​Sonner

​Backend integration

​Firebase

​Logging

​Pino

​pino-pretty

​Development tools

​ESLint

​Prettier

​Sharp

​Package manager

​pnpm

​Runtime requirements

​Node.js

​Environment variables

​Build output

Build docs developers (and LLMs) love