$orderId]; $ch = curl_init($apiBaseUrl . '/check-status'); curl_setopt_array($ch, [ CURLOPT_POST => true, CURLOPT_POSTFIELDS => json_encode($payload), CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 15, CURLOPT_HTTPHEADER => [ 'Content-Type: application/json', 'X-API-Key: ' . $apiKey, 'X-API-Secret: ' . $apiSecret ] ]); $response = curl_exec($ch); $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE); curl_close($ch); $data = json_decode($response, true); if ($httpCode === 200 && isset($data['status']) && $data['status'] === 'success') { $txnVerified = $data['data']; } else { $errorMessage = $data['error'] ?? 'Backend verification failed.'; } } else { $errorMessage = 'Invalid callback parameters.'; } // Render the beautiful success / failure receipt renderReceiptHTML($txnVerified, $errorMessage, $orderId); } else { // ----------------------------------------------------------------- // INITIATION STAGE: Trigger payment and redirect customer // ----------------------------------------------------------------- $orderId = 'ORD_' . time() . '_' . rand(1000, 9999); $amount = '10.00'; // Target amount in INR $customerName = 'Demo Customer'; // Redirect callback URL back to this script $callbackUrl = $protocol . $_SERVER['HTTP_HOST'] . $_SERVER['SCRIPT_NAME'] . '?action=callback'; $payload = [ 'amount' => $amount, 'order_id' => $orderId, 'customer_name' => $customerName, 'description' => 'Demo Payment Simulation', 'callback_url' => $callbackUrl ]; // Request new checkout link from PayIndia REST API $ch = curl_init($apiBaseUrl . '/create-order'); curl_setopt_array($ch, [ CURLOPT_POST => true, CURLOPT_POSTFIELDS => json_encode($payload), CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 15, CURLOPT_HTTPHEADER => [ 'Content-Type: application/json', 'X-API-Key: ' . $apiKey, 'X-API-Secret: ' . $apiSecret ] ]); $response = curl_exec($ch); $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE); $curlErr = curl_error($ch); curl_close($ch); if ($curlErr) { renderErrorHTML('Connection Failure', 'Failed to connect to gateway endpoint: ' . $curlErr, $payload, $apiBaseUrl); } else { $data = json_decode($response, true); if ($httpCode === 201 && isset($data['status']) && $data['status'] === 'success') { $paymentUrl = $data['data']['payment_url']; // Redirect customer immediately to payment checkout link header('Location: ' . $paymentUrl); exit; } else { // Render credentials error screen $detail = $data['error'] ?? 'Please confirm your X-API-Key and X-API-Secret credentials are set correctly inside the source code of this file.'; renderErrorHTML('API Authentication Failed', $detail, $payload, $apiBaseUrl, $data); } } } // ===================================================================== // Helper Functions to Render Responsive HTML Screens // ===================================================================== function renderReceiptHTML($txn, $error, $orderId) { ?> Transaction Receipt - PayIndia Demo

Payment Successful!

Transaction verified via gateway API

Order ID
Customer Name
Verified Amount ₹
UTR Reference
Payment Method
Paid Timestamp

Verification Failed

Order ID
Payment Status Unverified / Failed
Return to Demo Page
Checkout Setup Error - PayIndia

PayIndia checkout gateway integration guide

Our payment simulator page encountered an error when trying to request a checkout session:

Error Details:
How to Fix This:
  1. Open demo.php in a text editor.
  2. Locate variables $apiKey and $apiSecret at the top of the file (lines 14 & 15).
  3. Replace the mock credentials with the active API keys generated inside your merchant dashboard.
  4. Refresh this page to run the checkout redirect automatically.
Target Endpoint URL
Request Payload Sent
Raw Response Received