pos-mm

pos-mm is an open-source Point of Sale (POS) library built to replace outdated and expensive systems many restaurants still rely on. It started as a project for my family-owned restaurant and is designed to provide a modern, flexible, and affordable foundation for handling orders, payments, receipts, tables, inventory, and reports.

The library focuses on being reusable and framework-agnostic. It can be integrated into web applications, desktop software, or custom automation workflows. Developers can build complete POS systems on top of pos-mm without having to implement the core business logic themselves.

Features

• Menu Management – create and categorize menu items
• Orders – link orders to menu items, tables, and staff
• Payments – support multiple payment methods per order
• Users and Roles – waiter, cashier, admin with role-based permissions
• Table Management – open, close, and merge tables
• Inventory Tracking – optional stock deduction tied to menu items
• Receipts – generate itemized receipts for orders
• Reports – daily totals, top-selling items, payment breakdowns
• Database Utilities – simple setup and initialization helpers

Installation

Install the package from PyPI:

pip install pos-mm

Requirements

• Python 3.9+
• Dependencies listed in requirements.txt

To install all dependencies for development:

pip install -r requirements.txt

Quick Start

1. Initialize a database

from mm_pos.db import init_db, MenuItemDB

# In-memory SQLite database for testing
Session = init_db("sqlite:///:memory:")
session = Session()

2. Create a menu item

burger = MenuItemDB(name="Burger", price=9.99, category="Food")
session.add(burger)
session.commit()

3. Create a user

from mm_pos.db import UserDB

alice = UserDB(name="Alice", role="waiter")
alice.set_pin("1234")  # securely hash the PIN
session.add(alice)
session.commit()

4. Create an order with items

from mm_pos.db import OrderDB, OrderItemDB

order = OrderDB(table_number=1, user=alice)
session.add(order)
session.commit()

session.add(OrderItemDB(order_id=order.id, menu_item_id=burger.id, qty=2))
session.commit()

5. Record a payment

from mm_pos.db import PaymentDB

payment = PaymentDB(order=order, method="cash", amount_given=25.0, user=alice)
session.add(payment)
session.commit()

6. Generate a receipt

from mm_pos.receipt import Receipt

receipt = Receipt(order)
print(receipt.generate_text())

Next Steps

• Explore InventoryManager for stock management
• Use TableManager for managing tables in a restaurant
• Generate reports with the Reports class
• Integrate with FastAPI to expose your POS system as a web service