Project Overview

SUStech is a modern e-commerce platform specialising in technology products for the Bangladeshi market. Built on PHP and MySQL with cPanel hosting, it delivers a frictionless shopping experience for non-technical users while providing a powerful admin panel for complete store management.

Brand Identity

Scope

This PRD covers the complete SUStech web platform including:

• Customer-facing storefront with full e-commerce functionality
• Google OAuth 2.0 authentication with mandatory Bangladeshi mobile number verification
• Multi-step product ordering, cart, and checkout with delivery configuration
• WhatsApp integration per product for direct seller contact
• Full-featured admin panel with dashboard analytics, product/order/customer management
• Promo code engine, support ticket system, and configurable legal pages
• cPanel + MySQL deployment with secure file storage

Objectives & Goals

Primary Objectives

Key Performance Indicators

Technology Stack

Core Technologies

Third-Party Integrations

File Structure

sustech/
├── index.php                  ← Homepage / Hero
├── .htaccess                  ← URL rewriting + security headers
├── config/
│   ├── db.php                 ← MySQL PDO connection
│   ├── google-oauth.php       ← OAuth credentials + flow
│   └── constants.php          ← Site-wide constants (colors, WhatsApp no.)
├── auth/
│   ├── login.php              ← Google OAuth redirect
│   ├── callback.php           ← OAuth callback handler
│   ├── mobile-verify.php      ← BD mobile number entry page
│   └── logout.php             ← Session destroy + redirect
├── pages/
│   ├── shop.php               ← Product listing + filters
│   ├── product.php            ← Single product detail
│   ├── cart.php               ← Shopping cart
│   ├── checkout.php           ← Checkout form + order placement
│   ├── order-success.php      ← Post-order confirmation
│   ├── my-orders.php          ← User order history
│   ├── my-cart.php            ← Saved cart
│   ├── support.php            ← Support ticket form + list
│   ├── edit-profile.php       ← Update name, mobile
│   ├── hot-products.php       ← Featured/hot products page
│   ├── about.php              ← About SUStech
│   └── contact.php            ← Contact form
├── admin/
│   ├── index.php              ← Admin dashboard
│   ├── login.php              ← Admin login (separate credentials)
│   ├── products.php           ← Product management + upload
│   ├── categories.php         ← Main + sub-category management
│   ├── orders.php             ← Order management
│   ├── customers.php          ← Customer list + profiles
│   ├── promo-codes.php        ← Promo code CRUD
│   ├── support-tickets.php    ← Ticket management
│   ├── legal-pages.php        ← Privacy + Terms editor
│   ├── footer-settings.php    ← Footer content editor
│   ├── delivery-charges.php   ← Delivery rate settings
│   └── logout.php             ← Admin logout
├── api/
│   ├── cart.php               ← Cart CRUD (AJAX)
│   ├── order.php              ← Place order (AJAX)
│   ├── search.php             ← Product search (AJAX)
│   ├── ticket.php             ← Support ticket submit (AJAX)
│   └── admin/
│       ├── product.php        ← Product CRUD
│       ├── order-status.php   ← Update order status
│       └── promo.php          ← Promo code validation
├── includes/
│   ├── header.php             ← Site header partial
│   ├── footer.php             ← Site footer partial
│   ├── auth-guard.php         ← Redirect if not logged in
│   ├── mobile-guard.php       ← Redirect if mobile not set
│   └── admin-guard.php        ← Admin auth check
├── assets/
│   ├── css/
│   │   ├── main.css           ← Global styles + design tokens
│   │   ├── animations.css     ← Keyframes + scroll-reveal
│   │   └── admin.css          ← Admin panel styles
│   ├── js/
│   │   ├── app.js             ← Global JS (nav, toast, scroll)
│   │   ├── shop.js            ← Filter, sort, search
│   │   ├── product.js         ← Gallery, qty, cart actions
│   │   ├── cart.js            ← Cart AJAX operations
│   │   └── admin.js           ← Admin panel interactions
│   └── images/
│       ├── logo.svg
│       ├── logo-white.svg
│       ├── favicon.ico
│       ├── products/          ← Uploaded product images
│       └── categories/        ← Category icons
└── uploads/
    ├── products/              ← Thumbnail + gallery images
    └── categories/            ← Category images

System Architecture

Application Flow

Session Architecture

Database Schema

All tables use InnoDB engine with UTF8MB4 charset. Foreign keys enforce referential integrity.

users

CREATE TABLE users (
  id            INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  google_id     VARCHAR(50)  UNIQUE NOT NULL,
  email         VARCHAR(150) UNIQUE NOT NULL,
  name          VARCHAR(100) NOT NULL,
  picture       VARCHAR(500),
  mobile        VARCHAR(14)  NULL,          -- BD format: +8801XXXXXXXXX
  is_active     TINYINT(1)   DEFAULT 1,
  created_at    TIMESTAMP    DEFAULT CURRENT_TIMESTAMP,
  updated_at    TIMESTAMP    DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

main_categories

CREATE TABLE main_categories (
  id        INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  name      VARCHAR(100) NOT NULL,
  slug      VARCHAR(120) UNIQUE NOT NULL,
  image     VARCHAR(300),
  sort_order INT DEFAULT 0,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

sub_categories

CREATE TABLE sub_categories (
  id               INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  main_category_id INT UNSIGNED NOT NULL,
  name             VARCHAR(100) NOT NULL,
  slug             VARCHAR(120) UNIQUE NOT NULL,
  image            VARCHAR(300),
  sort_order       INT DEFAULT 0,
  created_at       TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (main_category_id) REFERENCES main_categories(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

products

CREATE TABLE products (
  id               INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  name             VARCHAR(200) NOT NULL,
  slug             VARCHAR(220) UNIQUE NOT NULL,
  main_category_id INT UNSIGNED,
  sub_category_id  INT UNSIGNED,
  price            DECIMAL(12,2) NOT NULL,
  sell_price       DECIMAL(12,2),
  sku              VARCHAR(100),
  thumbnail        VARCHAR(300),
  features         TEXT,                    -- JSON array of feature strings
  description      LONGTEXT,
  is_featured      TINYINT(1) DEFAULT 0,    -- Hot Product flag
  is_active        TINYINT(1) DEFAULT 1,
  warranty_data    TEXT,                    -- JSON [{months, is_free, price}]
  created_at       TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at       TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  FOREIGN KEY (main_category_id) REFERENCES main_categories(id) ON DELETE SET NULL,
  FOREIGN KEY (sub_category_id)  REFERENCES sub_categories(id)  ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

product_images

CREATE TABLE product_images (
  id         INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  product_id INT UNSIGNED NOT NULL,
  image_path VARCHAR(300) NOT NULL,
  sort_order INT DEFAULT 0,
  FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

product_stock

CREATE TABLE product_stock (
  id         INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  product_id INT UNSIGNED NOT NULL,
  color      VARCHAR(50),
  qty        INT UNSIGNED DEFAULT 0,
  FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

orders

CREATE TABLE orders (
  id              INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  order_number    VARCHAR(20) UNIQUE NOT NULL,   -- e.g. SUS-20240512-0001
  user_id         INT UNSIGNED NOT NULL,
  status          ENUM('pending','confirmed','shipped','delivered','cancelled') DEFAULT 'pending',
  subtotal        DECIMAL(12,2) NOT NULL,
  delivery_charge DECIMAL(10,2) NOT NULL,
  discount        DECIMAL(10,2) DEFAULT 0,
  total           DECIMAL(12,2) NOT NULL,
  promo_code      VARCHAR(30),
  customer_note   TEXT,
  shipping_name   VARCHAR(100) NOT NULL,
  shipping_mobile VARCHAR(14)  NOT NULL,
  shipping_address TEXT        NOT NULL,
  shipping_city   VARCHAR(100) NOT NULL,
  created_at      TIMESTAMP   DEFAULT CURRENT_TIMESTAMP,
  updated_at      TIMESTAMP   DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  FOREIGN KEY (user_id) REFERENCES users(id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

order_items

CREATE TABLE order_items (
  id          INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  order_id    INT UNSIGNED NOT NULL,
  product_id  INT UNSIGNED,
  product_name VARCHAR(200) NOT NULL,     -- snapshot at time of order
  unit_price  DECIMAL(12,2) NOT NULL,
  qty         INT UNSIGNED NOT NULL,
  color       VARCHAR(50),
  subtotal    DECIMAL(12,2) NOT NULL,
  FOREIGN KEY (order_id)   REFERENCES orders(id)   ON DELETE CASCADE,
  FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

cart_items

CREATE TABLE cart_items (
  id         INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  user_id    INT UNSIGNED NOT NULL,
  product_id INT UNSIGNED NOT NULL,
  color      VARCHAR(50),
  qty        INT UNSIGNED DEFAULT 1,
  added_at   TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  UNIQUE KEY uq_cart (user_id, product_id, color),
  FOREIGN KEY (user_id)    REFERENCES users(id)    ON DELETE CASCADE,
  FOREIGN KEY (product_id) REFERENCES products(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

promo_codes

CREATE TABLE promo_codes (
  id             INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  code           VARCHAR(30) UNIQUE NOT NULL,
  discount_type  ENUM('percent','amount') NOT NULL,
  discount_value DECIMAL(10,2) NOT NULL,
  min_order      DECIMAL(10,2) DEFAULT 0,
  limit_per_user INT UNSIGNED DEFAULT 1,
  start_date     DATE,
  expire_date    DATE,
  is_active      TINYINT(1) DEFAULT 1,
  created_at     TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

promo_code_usage

CREATE TABLE promo_code_usage (
  id        INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  promo_id  INT UNSIGNED NOT NULL,
  user_id   INT UNSIGNED NOT NULL,
  order_id  INT UNSIGNED NOT NULL,
  used_at   TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (promo_id) REFERENCES promo_codes(id),
  FOREIGN KEY (user_id)  REFERENCES users(id),
  FOREIGN KEY (order_id) REFERENCES orders(id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

support_tickets

CREATE TABLE support_tickets (
  id         INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  user_id    INT UNSIGNED NOT NULL,
  order_id   INT UNSIGNED,
  subject    VARCHAR(200) NOT NULL,
  message    TEXT NOT NULL,
  mobile     VARCHAR(14),
  status     ENUM('open','in_progress','resolved','closed') DEFAULT 'open',
  admin_note TEXT,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  FOREIGN KEY (user_id)  REFERENCES users(id),
  FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

site_settings

CREATE TABLE site_settings (
  setting_key   VARCHAR(100) PRIMARY KEY,
  setting_value TEXT,
  updated_at    TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- Default rows:
INSERT INTO site_settings VALUES
('whatsapp_number',  '+8801XXXXXXXXX', NOW()),
('delivery_inside_dhaka',  '60', NOW()),
('delivery_outside_dhaka', '120', NOW()),
('footer_description', 'SUStech — Your trusted tech shop in Bangladesh.', NOW()),
('footer_address',  'Dhaka, Bangladesh', NOW()),
('footer_phone',    '+8801XXXXXXXXX', NOW()),
('footer_email',    'info@sustech.com.bd', NOW()),
('footer_facebook', '', NOW()),
('footer_instagram','', NOW()),
('footer_tiktok',   '', NOW()),
('footer_copyright','© 2024 SUStech. All rights reserved.', NOW()),
('privacy_content', '', NOW()),
('terms_content',   '', NOW());

admin_users

CREATE TABLE admin_users (
  id         INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  username   VARCHAR(50) UNIQUE NOT NULL,
  password   VARCHAR(255) NOT NULL,   -- bcrypt hashed
  email      VARCHAR(150),
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

Authentication Flow

All customer authentication uses Google OAuth 2.0. No password is ever stored. After OAuth, new users must enter a valid Bangladeshi mobile number before accessing protected actions.

Google OAuth 2.0 Flow

Mobile Number Validation Rules

• Must be exactly 11 digits
• Must begin with 01 followed by 3–9
• No duplicate mobile numbers allowed across accounts
• User can update mobile from Edit Profile (re-validation required)
• Admin can view but not modify mobile from Customer Management

Protected Routes

Admin Authentication

Admin login is completely separate from Google OAuth. Admins log in at /admin/login.php with a username and bcrypt-hashed password stored in the admin_users table. Admin sessions use a separate key (admin_id) so customer sessions cannot grant admin access.

Design System

Color Palette

Typography

Animation Principles

• Scroll-reveal: Elements fade + slide up (translateY 30px → 0, opacity 0 → 1) when entering viewport via IntersectionObserver. Duration 500ms, ease-out.
• Hero entrance: Staggered animation — logo first (200ms), tagline (400ms), CTA button (600ms).
• Product card hover: Scale 1 → 1.03, box-shadow deepens, "View Details" button slides up from bottom.
• Button hover: Background shift + subtle scale 0.98 on active.
• Page transitions: Soft opacity fade-in on load (opacity 0 → 1, 300ms).
• Toast notifications: Slide in from right (translateX 120% → 0), auto-dismiss after 3.5s with fade-out.
• Cart icon: Bounce animation on item add (+1 badge pulse).
• Skeleton loading: Shimmer effect on product cards while AJAX loading.

Component Specs

Buttons

Product Card

• Width: fluid (min 240px, max 320px)
• Border radius: 12px
• Background: --color-surface
• Border: 1px solid --color-border
• Thumbnail: 16:9 ratio, object-fit: cover
• Price: red, bold, 22px
• Original price: struck through if sell_price present
• Hover: card lifts (box-shadow), action buttons slide in from bottom

Mobile-First Breakpoints

Header & Navigation

Header Layout

The header is sticky (position: fixed top), full-width, with a semi-transparent dark background and bottom border. On scroll, a solid black background drops in with a subtle shadow.

Header Elements (Left → Right)

Account Dropdown (Logged In)

Clicking the account icon opens a dropdown with the user's Google profile picture and name at the top, followed by:

• Dashboard
• My Orders
• My Cart
• Support Tickets
• Edit Profile
• Logout (red, bottom)

Homepage Sections

1. Hero Section: Full-screen dark background with animated gradient overlay. Bold headline, sub-text, and two CTAs: "Shop Now" (primary red) and "Hot Products" (secondary outline). Animated floating tech product images on right.
2. Category Grid: Main categories displayed as icon cards in a responsive grid with hover animation.
3. Hot Products: Horizontally scrollable row of featured product cards.
4. Features Banner: 4-column row: Free delivery info, Warranty, Genuine products, Customer support.
5. Latest Products: Grid of newest 8 products.
6. Testimonials: Static review carousel / grid.
7. Newsletter Banner: CTA to contact section.

Shop & Products

Shop Page — Filter Sidebar

Behaviour

• Filters update URL query params (?cat=&sub=&min=&max=&sort=) for shareable URLs
• AJAX fetch re-renders product grid without full page reload
• Mobile: filter sidebar collapses into a bottom sheet / modal overlay
• Result count displayed: "Showing 24 of 156 products"
• Pagination: 24 products per page, numbered + previous/next
• Search bar at top: live AJAX search with debounce (300ms)

Product Card

WhatsApp Button Behaviour

Product Detail Page

Cart & Checkout

Cart Page

Displays all items in cart_items for the logged-in user. Each row shows: thumbnail, product name, color, unit price, quantity (editable), subtotal. Qty changes trigger AJAX update. Remove button (×) removes item. Cart totals section on right: subtotal, delivery charge (based on city), discount (if promo applied), total.

Promo Code

Text input + "Apply" button. AJAX POST to /api/promo.php. Server validates: code exists, is active, within date range, min order met, user hasn't exceeded limit. Returns discount amount. Displayed in cart summary. Error toast if invalid.

Checkout Flow

Delivery Charge Logic

My Orders Page

Lists all orders for the logged-in user in reverse chronological order. Each row: Order Number, Date, Total (BDT), Status pill, "View Details" button. Clicking View Details expands an accordion showing all order items, shipping address, and timeline of status changes.

Admin Panel

The admin panel (/admin/) is a separate PHP application with its own authentication, layout, and styles. It is inaccessible to any user without a valid admin session.

Admin Sidebar Navigation

• Dashboard
• Products
• Categories
• Orders
• Customers
• Promo Codes
• Support Tickets
• Legal Pages
• Footer
• Delivery Charges
• Logout

Dashboard

Stats Cards (Top Row)

Recent Orders Table

Product Management

Product List Table Columns

Search bar (live filter by name/SKU), then table: ID | Thumbnail | Product Name | Category | Price | Stock | Status (Active/Hidden badge) | Actions (Edit / Delete).

Add / Edit Product Form

Category Management

Main Category

Form: Name, URL Slug (auto), Icon/Image (1:1, 1 file). Table: Image | Name | Slug | Sub-category count | Edit / Delete.

Sub-Category

Form: Main Category select, Sub-name, URL Slug, Image (1:1, 1 file). Table: Image | Main Category | Sub-category | Slug | Edit / Delete.

Order Management

Order List

Filter tabs at top: All | Pending | Confirmed | Shipped | Delivered | Cancelled. Each shows count badge. Table columns: Order ID | Customer | City | Shipping (BDT) | Amount | Status | Date | Actions.

Manage Order Modal / Page

Update Fulfillment Status

Dropdown: Pending → Confirmed → Shipped → Delivered → Cancelled. "Update Status" button. Status changes are logged. Customer gets email notification on status update.

Ordered Items Table

Additional Order Info Sections

• Customer Profile: Name, email, mobile, link to full customer profile and order history.
• Shipping Details: Recipient name, mobile, full address, city.
• Customer Note: Any note the customer left at checkout.
• Promo Code: Code used and discount amount (if any).

Customer Management

Customer List

Search bar (by name, email, mobile). Table: Avatar + Name | Contact Info (email + mobile) | Joined Date | Orders count | Total Spent (BDT) | Status (Active/Deactivated) | Actions (View Profile).

Customer Profile View

Promo Code Management

New Promo Code Form

Promo Code List Table

Columns: Code | Discount | Validity (start–expire dates) | Limit per user | Usage count | Status | Actions (Edit / Delete / Toggle Active).

Validation Logic (checkout)

1. Code exists and is_active = 1
2. Current date is within start_date and expire_date (if set)
3. Order subtotal >= min_order
4. User usage count < limit_per_user
5. If percent: discount = subtotal × (value/100), capped at subtotal
6. If amount: discount = min(value, subtotal)

Support Tickets

Customer Support Page

Auth + mobile required. Customer fills out: Subject (dropdown presets + custom), Order ID (optional, with order picker), Message (textarea), Pre-filled mobile. Submit creates a ticket. Customer sees their open tickets below the form with current status.

Admin — Ticket List

Columns: Ticket # | User (name + email) | Subject | Status pill | Date | Actions (Process / Delete).

Process Ticket Panel

Ticket Status Flow

Footer & Delivery Settings

Footer Admin Editor

Site Footer Layout (Front-end)

4-column layout on desktop, stacked on mobile:

• Col 1: Logo + short description
• Col 2: Quick Links (Home, Shop, Hot Products, About, Contact)
• Col 3: Contact info (address, phone, email)
• Col 4: Social icons (Facebook, Instagram, TikTok) + newsletter hint
• Bottom bar: Copyright text + Privacy Policy | Terms & Conditions links

Legal Pages Admin Editor

Two sections: Privacy Policy and Terms & Conditions. Each has a rich text / textarea editor. Content saved to site_settings. Front-end /pages/privacy.php and /pages/terms.php render this content inside the site layout.

Delivery Charge Settings

Security Requirements

Authentication Security

• All OAuth state tokens are random 32-byte hex values (CSRF protection)
• Google access tokens are never stored in DB; only user profile data
• Admin passwords are bcrypt-hashed (cost factor 12)
• Admin login rate-limited: max 5 failed attempts per 15 minutes (stored in login_attempts table or APCu)
• Sessions regenerated after login (session_regenerate_id(true))
• Session cookie: HttpOnly, Secure, SameSite=Strict

Input Validation & SQL Injection Prevention

• All DB queries use PDO prepared statements — no string interpolation
• All user input sanitized with htmlspecialchars() before output
• File uploads: validate MIME type via finfo_file(), not just extension; regenerate filenames; store outside webroot if possible
• Integer IDs validated with filter_var($id, FILTER_VALIDATE_INT)
• AJAX endpoints verify X-Requested-With: XMLHttpRequest header

CSRF Protection

• All state-changing forms include a hidden CSRF token generated per session
• Token validated server-side on every POST
• AJAX requests include CSRF token in X-CSRF-Token header

HTTP Security Headers (.htaccess)

Header always set X-Frame-Options "SAMEORIGIN"
Header always set X-Content-Type-Options "nosniff"
Header always set X-XSS-Protection "1; mode=block"
Header always set Referrer-Policy "strict-origin-when-cross-origin"
Header always set Permissions-Policy "geolocation=(), microphone=(), camera=()"
# HSTS (enable after SSL confirmed)
Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"

Data Privacy (PDPA Compliance Basics)

• Only data necessary for order fulfilment is collected (name, email, mobile, address)
• Google profile picture URL stored (not the image itself)
• Privacy Policy page clearly lists what data is collected and why
• Admin cannot view or modify user Google tokens
• Account deactivation (not deletion) available via admin; full deletion policy described in Privacy Policy

API Endpoints

All API endpoints are PHP files returning application/json. All state-changing endpoints require POST method and CSRF token validation.

Standard Response Format

{
  "success": true | false,
  "message": "Human-readable message",
  "data": { ... }   // Optional payload
}

Deployment Guide

cPanel Setup

PHP Configuration Requirements

Development Milestones