PHP quickstart (WooCommerce and other carts)

<?php
const PLATNOVA_BASE = 'https://api.platnova.com';          // sandbox: https://sandbox.api.platnova.co
$apiKey        = getenv('PLATNOVA_API_KEY');
$webhookSecret = getenv('PLATNOVA_WEBHOOK_SECRET');

<?php
function platnova(string $method, string $path, ?array $body = null, array $headers = []): array
{
    $ch = curl_init(PLATNOVA_BASE . $path);
    $h = array_merge(['X-API-Key: ' . getenv('PLATNOVA_API_KEY'), 'Accept: application/json'], $headers);
    if ($body !== null) {
        $h[] = 'Content-Type: application/json';
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body));
    }
    curl_setopt_array($ch, [
        CURLOPT_CUSTOMREQUEST  => $method,
        CURLOPT_HTTPHEADER     => $h,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT        => 30,
    ]);
    $raw = curl_exec($ch);
    if ($raw === false) {
        throw new RuntimeException('Platnova unreachable: ' . curl_error($ch));
    }
    $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    return ['status' => $status, 'body' => json_decode($raw, true)];
}

<?php
function start_payment(array $order): string
{
    $res = platnova('POST', '/v1/checkout', [
        'email'             => $order['email'],
        'first_name'        => $order['first_name'],
        'last_name'         => $order['last_name'],
        'amount'            => round($order['total'], 2),       // major units, e.g. 25000.00 naira
        'currency'          => strtolower($order['currency']),  // e.g. "ngn"
        'partner_reference' => (string) $order['id'],           // your order id, echoed in checkout.paid
        'success_url'       => 'https://shop.example.com/checkout/order-received/' . $order['id'],
        'cancel_url'        => 'https://shop.example.com/cart',
    ], ['Idempotency-Key: order-' . $order['id'] . '-attempt-' . $order['attempt']]);

    if ($res['status'] === 403 && ($res['body']['data']['code'] ?? '') === 'entity_not_active') {
        throw new RuntimeException('This store has not finished going live on Platnova.');
    }
    if ($res['status'] !== 200 || empty($res['body']['data']['id'])) {
        throw new RuntimeException('Could not start payment: ' . ($res['body']['message'] ?? 'HTTP ' . $res['status']));
    }

    $checkout = $res['body']['data'];
    save_order_meta($order['id'], 'platnova_checkout_id', $checkout['id']); // keep it: you verify and refund with it
    return $checkout['url'];                                               // redirect the customer here
}

<?php
$raw   = file_get_contents('php://input');                     // the raw body, before any json_decode
$given = $_SERVER['HTTP_X_PLATNOVA_SIGNATURE'] ?? '';
$expected = 'sha256=' . hash_hmac('sha256', $raw, getenv('PLATNOVA_WEBHOOK_SECRET'));

if (!hash_equals($expected, $given)) {
    http_response_code(401);                                   // not 200: we want Platnova to retry and warn us
    exit;
}

$event = json_decode($raw, true);
if (($event['event'] ?? '') === 'checkout.paid') {
    queue_payment_check($event['data']['checkout_id'], $event['data']['partner_reference'] ?? null);
}
http_response_code(200);                                       // answer fast; do the work in step 4

<?php
function confirm_payment(string $orderId): bool
{
    $checkoutId = get_order_meta($orderId, 'platnova_checkout_id');
    $order      = load_order($orderId);

    $res = platnova('POST', '/v1/payments/verify', ['reference' => $checkoutId]);
    if ($res['status'] !== 200) {
        return false;                                          // 400 "payment not found": not paid yet
    }
    $p = $res['body']['data'];

    $paid = $p['status'] === 'success'
        && $p['checkout_id'] === $checkoutId
        && strcasecmp($p['currency'], $order['currency']) === 0
        && abs($p['amount'] - round($order['total'], 2)) < 0.005;   // default fee_bearer: you get the full amount

    if ($paid) {
        mark_order_paid_once($orderId, $checkoutId, $p['ref']);     // unique on checkout id: a repeat does nothing
    }
    return $paid;
}

<?php
function refund(string $orderId, ?float $amount, string $reason): array
{
    $checkoutId = get_order_meta($orderId, 'platnova_checkout_id');
    $body = ['reason' => $reason, 'idempotency_key' => 'order-' . $orderId . '-refund-1'];
    if ($amount !== null) {
        $body['amount'] = round($amount, 2);                   // omit for a full refund
    }
    $res = platnova('POST', '/v1/checkout/' . rawurlencode($checkoutId) . '/refund', $body);
    if ($res['status'] >= 400) {
        throw new RuntimeException($res['body']['message'] ?? 'Refund refused');
    }
    return $res['body']['data'];                               // status: pending | processing | succeeded | failed
}