Kasir-Go API

Kasir-Go is a robust Point of Sale (POS) Backend API built with Go (Golang) and Gin Gonic. It follows a strict role-based access control system (Admin vs Cashier) and provides comprehensive endpoints for managing retail operations.

Features

• Strict Role-Based Auth: Distinct access levels for 'admin' and 'kasir'.
• Atomic Transactions: Ensures data integrity for stock reductions during transactions.
• Product & Stock Management: Admin-controlled inventory system.
• Dynamic Payment Methods: Configurable payment options.
• Operational Security: Secured endpoints using JWT with BCrypt hashing.
• Documentation: Integrated Swagger UI.

Tech Stack

• Language: Go 1.25+
• Framework: Gin Gonic
• Database: PostgreSQL
• ORM: GORM
• Auth: JWT & Bcrypt

Installation & Run

1. Clone Repository

   git clone https://github.com/doeta/Kasir-Go.git
   cd Kasir-Go

2. Setup Environment Create .env:

   DB_HOST=localhost
   DB_USER=postgres
   DB_PASSWORD=yourpassword
   DB_NAME=kasir_db
   DB_PORT=5432
   JWT_SECRET=supersecretkey
   PORT=8080

3. Run Application

   go mod tidy
   go run main.go

   The application will automatically migrate database tables and seed a default admin user on the first run.

Roles & Permissions

• Admin: Full access to manage users, products, and payment methods. Cannot create transactions.
• Kasir: Dedicated role for processing transactions (sales). Read-only access to products and payments.

API Endpoints

Public

• GET / : Health check & API status.
• POST /api/login : Login to receive JWT Token.
• POST /api/register : Public registration (automatically assigned 'kasir' role).

Protected (Requires Bearer Token)

Transactions

• POST /api/transactions : Create new transaction. (Kasir Only)
• GET /api/transactions : View transaction history.

Products

• GET /api/products : List all products.
• POST /api/products : Add product. (Admin Only)
• PUT /api/products/:id : Update product. (Admin Only)
• DELETE /api/products/:id : Delete product. (Admin Only)

Categories

• GET /api/categories : List all categories.
• POST /api/categories : Add category. (Admin Only)
• PUT /api/categories/:id : Update category. (Admin Only)
• DELETE /api/categories/:id : Delete category. (Admin Only)

Payments

• GET /api/payments : List payment methods.
• POST /api/payments : Add payment method. (Admin Only)
• PUT /api/payments/:id : Update payment method. (Admin Only)
• DELETE /api/payments/:id : Delete payment method. (Admin Only)

User Management (Admin Only)

• GET /api/admin/users : List all users.
• POST /api/admin/users : Create specific user (Admin/Kasir).
• PUT /api/admin/users/:id : Update user data.
• DELETE /api/admin/users/:id : Delete user.

API Documentation

Swagger UI is available at: http://localhost:8080/swagger/index.html

Default Credentials

If the database is empty, the system generates:

• Username: admin
• Password: admin123