PHP SDK

use Fortpesa\Client;

$fortpesa = new Client(getenv('FORTPESA_API_KEY'));

$fortpesa = new Client(getenv('FORTPESA_API_KEY'), [
    'base_url'    => 'https://fortpesa.co.ke/api/v1',
    'timeout'     => 30,
    'max_retries' => 2,
    'http_client' => new MyGuzzleAdapter(), // implements Fortpesa\Http\HttpClientInterface
]);

$tx = $fortpesa->payments->stk(
    150,                    // whole KES
    '0712345678',           // 07..., 01..., 2547..., +2547... all accepted
    'INV-2041',             // your reference, max 12 chars
    42,                     // Channel ID from the Channels page
    'order-2041-attempt-1'  // idempotency key (optional but recommended)
);

echo $tx->uuid;    // poll this, or wait for a webhook
echo $tx->status;  // "pending" - the customer now has an M-PESA prompt

$tx = $fortpesa->transactions->get($uuid);                       // fresh status (live-confirmed with M-Pesa)
$tx = $fortpesa->transactions->list('success', 25);              // newest first; may lag behind get()
$tx = $fortpesa->transactions->findByAccountReference('INV-2041');

if ($tx->isSuccessful()) {
    // mark the order paid, idempotently
}

$balance = $fortpesa->wallet->balance();
echo $balance->balance;  // whole KES

use Fortpesa\Exception\ApiException;
use Fortpesa\Exception\FortpesaException;

try {
    $fortpesa->payments->stk(150, '0712345678', 'INV-2041', 42);
} catch (ApiException $e) {
    echo $e->getHttpStatus();  // 402, 422, 503, ...
    echo $e->getErrorCode();   // the API error code, see the errors reference
    echo $e->getResponseBody();
} catch (FortpesaException $e) {
    // transport failure after retries were exhausted
}

use Fortpesa\Webhook;
use Fortpesa\Exception\SignatureVerificationException;

try {
    $event = Webhook::constructEventFromGlobals(getenv('FORTPESA_WEBHOOK_SECRET')); // whsec_...
} catch (SignatureVerificationException $e) {
    http_response_code(400);
    exit;
}
http_response_code(200);

// Notification, not proof: re-fetch before fulfilling.
$tx = $fortpesa->transactions->get($event->uuid());
if ($tx->isSuccessful()) {
    // mark the order paid, idempotently
}

$event = Webhook::constructEvent($rawBody, $signatureHeader, $timestampHeader, $secret);