KCB M-Pesa STK Push Gateway

💳 KCB M-Pesa Express WooCommerce Gateway A production WordPress plugin enabling KCB M-Pesa STK Push payments in WooCommerce stores across Kenya and East Africa. Free core + Pro tier with extended features. Why this exists: KCB's M-Pesa Express API is widely used in Kenya but has no official WooCommerce integration. This plugin fills that gap with a clean, extensible implementation. Features Free - ✅ Full STK Push payment flow at WooCommerce checkout - ✅ Secure OAuth2 token generation with KCB API - ✅ Real-time callback handling → automatic order status updates - ✅ Admin callback log dashboard (view, download, clear) - ✅ Email alerts on payment failures Pro - 🔐 License key activation system - 📊 CSV export of payment logs - 📣 Slack / Telegram payment notifications (planned) - 🎨 Advanced checkout UI customisation Architecture Design decisions: - Abstract base class (class-gateway-base.php) makes it straightforward to extend for other KCB payment products or M-Pesa providers - Callbacks are logged to a flat file (wp-content/mpesa-callback-log.txt) — avoids DB write overhead during high-volume payment events - Token generation is handled per-request with short TTL — avoids stale