Let’s create a complete, end-to-end, beginner-friendly API flow for a simple login + fetch dashboard data example.

This will cover everything from form —> validation —> service —> Axios —> backend —> React Query —> type-safe response —> toast/UI updates, including typed API response.

• 7.1 Folder Structure
• 7.2 Environment Variable Setup (config/env.ts)
• 7.3 Constant — Shared Values (config/constants.ts)
• 7.4 Endpoints Setup (config/routes.ts)
• 7.5 Axios Instance (lib/axios.ts)
• 7.6 Auth Service (features/auth/login/service/auth.api.ts)
• 7.7 Dashboard Service (features/dashboard/service/auth.api.ts)
• 7.8 Types for API (Request & Response || Basic Interface )
• 7.9 Zod Schema (features/auth/login/schema/login.schema.ts)
• 7.10 React Query Hooks for both Dashboard and Login
• 7.11 Login Form Component (features/auth/login/components/login-form.tsx)
• 7.21 Fetch User Data