Paystack Payment Integration with AJAX and PHP

Step 3: Backend Payment Verification with PHP

The callback in the above script sends the payment reference to a PHP backend script for verification. Below is the verify-payment.php script:

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $reference = $_POST['reference']; // Get the transaction reference

    if (!$reference) {
        echo json_encode(['status' => false, 'message' => 'No reference supplied']);
        exit;
    }

    $url = 'https://api.paystack.co/transaction/verify/' . $reference;

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Authorization: Bearer your-secret-key-here' // Replace with your Paystack secret key
    ]);

    $response = curl_exec($ch);
    curl_close($ch);

    $result = json_decode($response, true);

    if ($result['status'] && $result['data']['status'] === 'success') {
        // Payment was successful
        echo json_encode([
            'status' => true,
            'message' => 'Payment verified successfully',
            'reference' => $reference
        ]);
    } else {
        // Payment verification failed
        echo json_encode([
            'status' => false,
            'message' => 'Payment verification failed',
            'reference' => $reference
        ]);
    }
}
?>

Step 4: Testing Your Integration

1. Use the test keys provided by Paystack to test your integration.
2. Navigate to the Paystack documentation and use the test card details for simulated payments.
3. Ensure that your verification script handles errors appropriately.
4. Once testing is complete, replace the test keys with live keys.

See also FlutterWave Payment Integration With PHP

See also Remita Payment Integration

Best Practices

1. Secure Your Keys:
   • Never expose your secret key on the frontend.
   • Use environment variables to store your keys securely.
2. Validate Inputs:
   • Ensure that the email and amount fields are properly validated before initiating payments.
3. Handle Errors Gracefully:
   • Inform users if something goes wrong during payment or verification.
   • Provide clear steps for retrying the payment.
4. Logging:
   • Log all payment references and verification responses for auditing purposes.

Conclusion

Paystack payment integration with AJAX and PHP can provide a seamless payment experience for your users. By following this guide, you’ve set up a secure and efficient payment flow with real-time feedback. Remember to test your implementation thoroughly and follow best practices to ensure a smooth experience for your users.