How to Accept UPI Payments on WooCommerce Without GST or Current Account (2026 Guide)

+--------------------+ +-------------------------+ +------------------------+ | WooCommerce Buyer | | WordPress / WooCommerce | | FamGateway Cluster | +--------------------+ +-------------------------+ +------------------------+ | | | | 1. Submit Cart Checkout | | | Selects "Instant UPI" | | |------------------------------>| | | | 2. POST /api/create-order | | | Headers: X-Api-Key | | | Body: amount, order_id | | |------------------------------->| | | | 3. Generate Session | | | Exact 300s TTL | | 4. Return checkout_url & QR | Unique dynamic QR | |<-------------------------------| | 5. Redirect to Checkout URL | | |<------------------------------| | | | | | 6. Scan Dynamic QR Code via UPI App (GPay/PhonePe/FamPay) | |--------------------------------------------------------------->| | | | 7. Real-Time Ingestion | | | Validate Bank UTR | | 8. Signed Webhook Callback | Lock Record | | Header: Signature (HMAC) | | |<-------------------------------| | | | | | 9. Validate HMAC-SHA256 | | | Verify Bank UTR Uniqueness | | | $order->payment_complete() | | | Status → "Processing" | | | | | 10. Thank You Screen & Digital Files Unlocked Automatically | |<------------------------------| |

<?php
/**
 * Plugin Name: FamGateway UPI for WooCommerce
 * Plugin URI: https://famgateway.in/
 * Description: Accept instant UPI payments (GPay, PhonePe, Paytm, FamPay) on WooCommerce without GST or a current account. 0% transaction fees.
 * Version: 2.1.0
 * Author: Aryan Gupta (Aryanispe)
 * Author URI: https://aryanispe.in/
 * License: GPLv2 or later
 * Text Domain: famgateway-wc
 */

if (!defined('ABSPATH')) {
    exit; // Prevent direct execution
}

add_action('plugins_loaded', 'famgateway_init_woocommerce_gateway', 11);

function famgateway_init_woocommerce_gateway() {
    if (!class_exists('WC_Payment_Gateway')) {
        return;
    }

    class WC_Gateway_FamGateway extends WC_Payment_Gateway {
        public function __construct() {
            $this->id = 'famgateway';
            $this->icon = apply_filters('famgateway_wc_icon', 'https://famgateway.in/favicon.png');
            $this->has_fields = false;
            $this->method_title = __('FamGateway Instant UPI', 'famgateway-wc');
            $this->method_description = __('Accept instant, zero-commission UPI payments via Google Pay, PhonePe, Paytm, and FamPay.', 'famgateway-wc');

            $this->init_form_fields();
            $this->init_settings();

            $this->title = $this->get_option('title', 'Instant UPI (GPay / PhonePe / Paytm / FamPay)');
            $this->description = $this->get_option('description', 'Pay directly from your favorite UPI app. 100% secure with instant order confirmation.');
            $this->api_key = $this->get_option('api_key');

            // Admin configuration hook
            add_action('woocommerce_update_options_payment_gateways_' . $this->id, [$this, 'process_admin_options']);
            
            // Webhook endpoint hook: /wc-api/famgateway_webhook
            add_action('woocommerce_api_famgateway_webhook', [$this, 'handle_webhook_callback']);
        }

        public function init_form_fields() {
            $this->form_fields = [
                'enabled' => [
                    'title'   => __('Enable/Disable', 'famgateway-wc'),
                    'type'    => 'checkbox',
                    'label'   => __('Enable FamGateway UPI Gateway', 'famgateway-wc'),
                    'default' => 'yes'
                ],
                'title' => [
                    'title'       => __('Title', 'famgateway-wc'),
                    'type'        => 'text',
                    'description' => __('Payment method title that the customer sees during checkout.', 'famgateway-wc'),
                    'default'     => __('Instant UPI (GPay / PhonePe / Paytm / FamPay)', 'famgateway-wc'),
                    'desc_tip'    => true,
                ],
                'description' => [
                    'title'       => __('Description', 'famgateway-wc'),
                    'type'        => 'textarea',
                    'description' => __('Payment method description displayed to customers on the checkout page.', 'famgateway-wc'),
                    'default'     => __('Pay seamlessly using any UPI app. Order fulfills automatically in seconds.', 'famgateway-wc'),
                ],
                'api_key' => [
                    'title'       => __('FamGateway API Key', 'famgateway-wc'),
                    'type'        => 'password',
                    'description' => __('Obtain your live API key from the FamGateway Merchant Dashboard (famgateway.in).', 'famgateway-wc'),
                    'default'     => '',
                ]
            ];
        }

        public function process_payment($order_id) {
            $order = wc_get_order($order_id);
            if (!$order) {
                wc_add_notice(__('Order record could not be retrieved.', 'famgateway-wc'), 'error');
                return;
            }

            if (empty($this->api_key)) {
                wc_add_notice(__('FamGateway API Key is not configured in store settings.', 'famgateway-wc'), 'error');
                return;
            }

            $endpoint = 'https://famgateway.in/api/create-order';
            $webhookUrl = home_url('/wc-api/famgateway_webhook');
            $redirectUrl = $this->get_return_url($order);

            $payload = [
                'amount'         => number_format((float)$order->get_total(), 2, '.', ''),
                'customer_name'  => trim($order->get_billing_first_name() . ' ' . $order->get_billing_last_name()),
                'customer_email' => $order->get_billing_email(),
                'customer_phone' => $order->get_billing_phone(),
                'redirect_url'   => $redirectUrl,
                'webhook_url'    => $webhookUrl,
                'custom_id'      => 'WC_' . $order->get_id() . '_' . time()
            ];

            $response = wp_remote_post($endpoint, [
                'headers' => [
                    'Content-Type' => 'application/json',
                    'X-Api-Key'    => $this->api_key
                ],
                'body'    => wp_json_encode($payload),
                'timeout' => 15
            ]);

            if (is_wp_error($response)) {
                wc_add_notice(__('Communication with UPI Gateway failed: ', 'famgateway-wc') . $response->get_error_message(), 'error');
                return;
            }

            $responseCode = wp_remote_retrieve_response_code($response);
            $rawBody      = wp_remote_retrieve_body($response);
            $data         = json_decode($rawBody, true);

            $checkoutUrl = $data['checkout_url'] ?? $data['payment_url'] ?? '';

            if ($responseCode === 200 && !empty($checkoutUrl)) {
                // Attach FamGateway order id to WooCommerce order meta
                $order->update_meta_data('_famgateway_order_id', sanitize_text_field($data['order_id']));
                $order->save();

                // Redirect customer to FamGateway dynamic checkout page
                return [
                    'result'   => 'success',
                    'redirect' => esc_url_raw($checkoutUrl)
                ];
            }

            $errorMsg = $data['message'] ?? __('Failed to generate dynamic UPI checkout session.', 'famgateway-wc');
            wc_add_notice($errorMsg, 'error');
            return;
        }

        public function handle_webhook_callback() {
            $rawPayload = file_get_contents('php://input');
            if (empty($rawPayload)) {
                status_header(400);
                exit('Empty request body');
            }

            $data = json_decode($rawPayload, true);
            if (!is_array($data) || empty($data['order_id']) || empty($data['status'])) {
                status_header(400);
                exit('Malformed payload');
            }

            // Verify HMAC-SHA256 signature using the merchant API key
            $receivedSignature = $_SERVER['HTTP_X_FAMGATEWAY_SIGNATURE'] ?? '';
            if (empty($receivedSignature)) {
                status_header(401);
                exit('Missing signature header');
            }

            $expectedSignature = hash_hmac('sha256', $rawPayload, $this->api_key);
            if (!hash_equals($expectedSignature, $receivedSignature)) {
                status_header(401);
                exit('Signature verification mismatch');
            }

            // Only act upon success events
            if ($data['status'] === 'success') {
                $famOrderId = sanitize_text_field((string)$data['order_id']);
                $utr        = sanitize_text_field((string)($data['utr'] ?? ''));

                // Query WooCommerce orders by FamGateway order meta
                $orders = wc_get_orders([
                    'meta_key'   => '_famgateway_order_id',
                    'meta_value' => $famOrderId,
                    'limit'      => 1
                ]);

                if (!empty($orders)) {
                    $order = $orders[0];

                    if ($order->has_status(['pending', 'on-hold', 'failed'])) {
                        // Mark order completed and record bank UTR
                        $order->payment_complete($utr);
                        $order->add_order_note(sprintf(
                            __('FamGateway UPI payment confirmed. Bank UTR: %s, Amount: INR %s', 'famgateway-wc'),
                            $utr,
                            $data['amount']
                        ));

                        status_header(200);
                        exit('Order successfully marked as paid');
                    }
                }
            }

            status_header(200);
            exit('Event acknowledged');
        }
    }
}

add_filter('woocommerce_payment_gateways', function($gateways) {
    $gateways[] = 'WC_Gateway_FamGateway';
    return $gateways;
});