Accept Alipay China payments inside WHMCS without third-party services or manual reconciliation. The Antom (Alipay+) gateway integrates directly with Ant Group's official Antom API to deliver QR-code checkout, automatic invoice settlement, and one-click refunds — all from the standard WHMCS admin panel. 100% free, no license server, no upsell.

Why Antom (Alipay+)

If your customer base includes mainland China users, Alipay is the dominant payment method — but most WHMCS Alipay gateways are stuck on the legacy openAPI, require a separate Chinese business entity, or rely on third-party aggregators that take an extra cut. Antom (Alipay+) is Ant Group's official cross-border product, designed for international merchants who want native Alipay acceptance without re-incorporating in China. This module is the production-grade WHMCS integration built on Antom's documented API.

QR-Code Checkout, No Redirects

Customers see the Alipay QR code rendered inline on the WHMCS invoice page and pay with the Alipay app on their phone. The QR image is fetched server-side and re-served as Base64 over HTTPS so there are no mixed-content warnings, and the page works on any modern browser without extra scripts. Mobile users get a deep link that opens the Alipay app directly.

Bank-Grade Security

Every API call is signed with RSA256 (SHA256-with-RSA) and every webhook is verified with the Antom platform public key before any database write. Timestamps are validated against a 15-minute tolerance window to block replay attacks, and OpenSSL key resources are explicitly freed for PHP 7.4 compatibility. SSL certificate verification is mandatory — never disabled, even in sandbox mode. Both PKCS#1 and PKCS#8 RSA private key formats are accepted.

Multi-Region, Multi-Currency

Switch between Antom's Asia, North America, and Europe API gateways with a single dropdown to route traffic through the lowest-latency region for your customers. Sandbox and production endpoints are toggled with one checkbox. The module supports USD, HKD, CNY, SGD, JPY, and any other currency configured in WHMCS, with correct minor-unit conversion (cents vs no-cents) applied automatically. Zero-decimal currencies like JPY, KRW, VND, and IDR are handled correctly so amounts never come through 100x off.

Automatic Invoice Processing

When a payment notification arrives, the gateway validates the signature, looks up the invoice by request ID (INV{id}T{timestamp}), guards against duplicate processing via WHMCS's checkCbTransID, and posts the payment with the correct amount and configured fee. The callback also enforces a Client-Id binding check (rejecting notifications meant for other merchants) and a cross-check between the original order amount/currency and the notification payload — defending against tampered or replayed callbacks. No cron jobs, no manual reconciliation.

Original-Path Refunds

Refunds are issued from the standard WHMCS invoice page. The gateway calls Antom's /payments/refund endpoint with a unique request ID (REF{id}T{timestamp}) and processes the asynchronous refund notification with the same signature verification as payment callbacks. Partial refunds are supported. Refund status is mirrored back to the WHMCS invoice automatically.

Flexible Fee Management

Configure a percentage fee, a fixed fee, or both. Fees are validated to prevent division-by-zero and integer overflow, and amounts are calculated with (int)round() instead of float-to-string casts to eliminate the half-cent rounding errors that plague many gateway implementations.

Why Free

We use Antom internally for our own WHMCS-based stores and ship the module as free, source-available code so the community can benefit from a properly engineered Alipay gateway. There is no license key, no phone-home, and no upsell. Production support is best-effort via our public contact channels.

Built-In Features

• ALIPAY_CN QR-code checkout (no redirect)
• Server-side Base64 QR relay (HTTPS-safe)
• RSA256 (SHA256-with-RSA) signing and verification
• Auto PEM key formatting (handles raw / wrapped keys)
• 15-minute timestamp tolerance (anti-replay)
• Mandatory SSL certificate verification
• Automatic invoice payment posting
• Idempotent callbacks via checkCbTransID
• Original-path refunds from WHMCS admin
• Asynchronous refund notification handling
• Multi-region API endpoints (Asia / NA / EU)
• Sandbox / production toggle
• Multi-currency support (USD / HKD / CNY / SGD / JPY / etc.)
• Configurable fees (percentage + fixed)
• Precise (int)round() amount calculations
• OpenSSL resource cleanup (PHP 7.4 compatible)
• XSS-safe HTML output
• Currency validation against gateway support list
• Gateway log integration for troubleshooting
• Self-update via Intally Updater
• Client-Id binding on callback (rejects notifications not for this merchant)
• Amount and currency cross-check on callback
• ISO 8601 Request-Time support (Antom standard format)
• Zero-decimal currency handling (JPY / KRW / VND / IDR)
• PKCS#1 and PKCS#8 RSA private key formats supported

Requirements

• WHMCS 8.0 or newer
• PHP 7.4 or newer
• OpenSSL extension (for RSA signing and verification)
• cURL extension (for Antom API calls)
• ionCube Loader

Setup in Five Minutes

1. Sign up at antom.com and create an API credential pair
2. Upload the module ZIP to your WHMCS root and extract
3. Configuration > System Settings > Payment Gateways > activate "Antom (Alipay+)"
4. Paste your Antom Client-Id, your private key, and Antom's public key
5. Choose your region (Asia / NA / EU) and toggle production mode

Support

Pre-sales questions and technical support reach us through our contact page (form, email, and Telegram, no login or account required). The module is free and open to community contributions — bug reports and pull requests are welcome.