1. Point of Sale

Reactive Alpine.js split-screen cart with search, categories, discount handling, and quick checkout.

2. Dashboard

Live KPIs, best-sellers, low-stock warnings, and inventory valuation at a glance.

3. Reports & Analytics

Sales summaries, best-selling products, low-stock alerts, and stock movement ledgers.

Active Project Case Study

StockFlow POS

A Full-Stack Laravel Point-of-Sale with Atomic Stock Deduction, Thermal Receipt Printing, and a Complete Inventory Audit Trail

Laravel 12 PHP 8.2 Vite 7 Alpine.js Tailwind CSS v4 Chart.js SQLite

Live Demo View Code

Note: this demo runs on Render's free tier and may take 30–60 seconds to spin up if it has been idle.

At a Glance

Problem: A retail store tracked stock in disconnected spreadsheets, causing overselling, stock-outs, and no audit trail.
Role: Designed and built the full-stack system: Laravel API, Alpine.js POS, schema, auth, and reporting.
Solution: A point-of-sale with atomic stock deduction, thermal receipt printing, and a stock-movement ledger.
Result: Server-side stock verification prevents overselling, and every movement is attributable to a user with a reason.
Proof: Live demo (Render free tier), GitHub repository, screenshots, and the schema and API documentation below.

Executive Summary

StockFlow POS is a production-ready point-of-sale and inventory management system built on Laravel 12. It replaces error-prone, spreadsheet-driven store operations with a transactional backend, a reactive Alpine.js checkout interface, and a complete audit trail for every stock movement.

Sales are processed inside a single database transaction that atomically deducts stock, records a stock_movements ledger entry, and returns change computation for cash, GCash, or card payments. A printable 80mm thermal receipt view completes the loop, making the system fully functional for a small retail counter out of the box.

The Manual Nightmare

• Guessing Stock Levels: Cashiers sell from memory while actual on-hand quantity lives in a disconnected spreadsheet.
• Overselling & Stock-outs: No low-stock warnings, so fast-moving items sell out before anyone notices.
• No Audit Trail: Adjustments, deliveries, and sales are undocumented, making shrinkage impossible to trace.
• Manual Receipts: Handwritten or manually typed receipts leave room for pricing and change errors.

The Digital Solution

• Atomic Checkout: Sales deduct stock and write ledger entries inside one DB::transaction().
• Live Stock Visibility: Dashboard surfaces low-stock alerts and inventory valuation in real time.
• Full Audit Trail: Every stock_in, sale, and adjustment is logged with the responsible user.
• Thermal Receipts: 80mm print-ready receipt preview with automatic change calculation on every sale.

Core Architecture

1. Transactional POS Engine

The POST /api/transactions endpoint is the heart of the system. Each sale runs inside a database transaction that:

Re-verifies current stock for every line item server-side, returning 422 if any item is oversold.
Deducts product stock atomically and writes a sale movement entry per product.
Captures a historical snapshot of product name and unit price on each line item, so old receipts remain accurate even after a product is edited or deleted.
Computes subtotal, discount, total, amount paid, and change, then returns a 201 Created response with the full receipt payload.

2. Reactive Alpine.js Frontend

Built with Vite 7 and Tailwind CSS v4, the POS page uses a lightweight Alpine.js cart component for instant, dependency-free reactivity:

Product search and category filtering without full page reloads.
Live cart totals, quantity steppers, and discount input (fixed or percentage).
A checkout modal with payment method, quick-cash buttons, and automatic change calculation.
An 80mm thermal receipt preview that triggers the browser's native @media print window.

3. Role-Based Access & Stock Audit

Users are assigned an admin or cashier role. Cashiers can process sales while admins manage products, categories, inventory, and reports. Every stock change — deliveries (stock_in), sales (sale), and manual corrections (adjustment) — is recorded with the responsible user and an optional reason for full traceability.

Database & Schema Design

A normalized relational schema (SQLite by default, MySQL/PostgreSQL-ready) keeps historical sales accurate while enabling fast reporting:

users

Auth + Roles

name string(255)
email [UNIQUE] string(255)
role admin | cashier
password string(255)
remember_token string nullable

products

Soft Deletes

sku [UNIQUE] string(100)
category_id [FK] unsigned bigint
price decimal(12,2)
stock_quantity integer
low_stock_threshold integer (default 5)

transactions

1 : * transaction_items

transaction_number string(100) UNIQUE
user_id [FK] Cashier
subtotal / total decimal(12,2)
payment_method cash | gcash | card
amount_paid / change decimal(12,2)

transaction_items

Historical Snapshot

transaction_id [FK CASCADE] unsigned bigint
product_id [FK SET NULL] nullable
product_name string snapshot
unit_price / subtotal decimal(12,2)
quantity integer

stock_movements

Audit Ledger

product_id [FK CASCADE] unsigned bigint
user_id [FK SET NULL] nullable
type stock_in | sale | adjustment
quantity (+/-) integer
reason string nullable

REST API Surface

A clean, versioned JSON API powers both the Blade frontend and any future mobile or integration clients:

Domain	Key Endpoints	Description
Auth	POST /api/login · logout · GET /api/user	Session-based auth with role-aware profile fetch.
Products	GET/POST/PUT/DELETE /api/products	Searchable list with category and low-stock filters; soft-delete safe.
Transactions	POST /api/transactions	Atomic sale: verify stock, deduct, write ledger, compute change.
Inventory	POST /api/inventory/stock-in · /adjust	Restock and manual adjustments with reasons, plus movement audit log.
Reports	GET /api/reports/*	Sales summary, best-sellers, low-stock, valuation, and movement totals.

Key Benefits & Tangible Outcomes

Zero Overselling

Server-side stock verification inside every sale guarantees cashiers can never sell more than what's actually on hand.

Complete Audit Trail

Every stock-in, sale, and adjustment is attributable to a user with a reason, eliminating shrinkage blind spots.

Historical Integrity

Line items snapshot product name and price at sale time, so past receipts stay correct after edits or deletes.

Counter-Ready Workflow

From scan to printed 80mm thermal receipt in seconds, with change calculated automatically — no calculator required.

Need a custom POS or inventory system?

Let's coordinate to build scalable Laravel backends, offline-first storefronts, or reporting dashboards tailored to your business.

Get in Touch →

← Back to Portfolio Next Case Study →