CartModules: SimplePay Payment Gateway

Accept Card Payments via OTP SimplePay in Your CS-Cart Store

Integrate OTP SimplePay -- Hungary's leading online payment gateway by OTP Bank -- directly into your CS-Cart or Multi-Vendor store. Customers pay securely using their credit or debit cards through SimplePay's hosted payment page.

Key Features

• Dual Checkout Modes — Choose between redirect (hosted page) or inline (iFrame popup) checkout
• On-Site Payment — Inline mode embeds iFrame on checkout page for seamless experience
• OTP SimplePay REST API v2 -- Modern API integration with HMAC-SHA384 signed requests
• Hosted Payment Page -- No card data touches your server (PCI SAQ A compliant)
• IPN (Instant Payment Notification) -- Real-time server-to-server payment confirmation
• Multi-Currency Support -- Accept payments in HUF, EUR, and USD
• Sandbox/Production Toggle -- Switch between test and live environments from the admin panel
• Configurable Order Statuses -- Map SimplePay events (SUCCESS, FAIL, CANCEL, TIMEOUT) to any CS-Cart order status
• HMAC-SHA384 Signature Verification -- All API communication and IPN callbacks are cryptographically verified
• Idempotent Callbacks -- Duplicate IPN notifications and return redirects are safely handled
• Transaction Query Fallback -- If IPN is delayed, the addon queries SimplePay directly for confirmation
• Automatic HUF Rounding -- Integer amounts for HUF as required by SimplePay

Requirements

• CS-Cart or Multi-Vendor 4.x
• PHP 7.1 or higher
• OTP SimplePay merchant account with API credentials (Merchant ID, Secret Key)

Checkout Modes

Redirect Mode

• Customer is redirected to SimplePay's hosted payment page
• Payment completed on the gateway's secure page
• Customer returns to your store after payment

Inline Mode

• Server creates payment session via SimplePay API
• SimplePay payment page embedded in iFrame on checkout page
• Customer pays without leaving your store

How It Works

1. Customer selects SimplePay at checkout and clicks "Place Order"
2. The addon creates a signed payment request and calls SimplePay's /v2/start endpoint
3. In redirect mode: customer is redirected to SimplePay's hosted page
4. In inline mode: SimplePay page embedded in iFrame on checkout
5. Customer enters card details and completes payment
6. SimplePay sends an IPN callback and redirects the customer back
7. The addon verifies the HMAC-SHA384 signature and updates the order status

Supported Currencies

• HUF -- Hungarian Forint (integer amounts)
• EUR -- Euro
• USD -- US Dollar

Installation

1. Go to Add-ons > Manage add-ons, click Manual installation, and upload the addon zip
2. Activate the addon and enter the license key
3. Go to Administration > Payment methods and create a new payment method
4. Select "SimplePay Payment Gateway" as the processor
5. Enter your Merchant ID and Secret Key from the SimplePay merchant portal
6. Configure order status mappings as desired
7. Save and test with sandbox mode before going live

Country & Region

This addon is designed primarily for merchants in Hungary and Central Europe. OTP SimplePay is widely used for online card payments in the Hungarian market and supports transactions in HUF, EUR, and USD.