quellabs / canvas-payments-klarna
Klarna payment gateway integration for the Canvas PHP framework
Package info
github.com/quellabs/canvas-payments-klarna
pkg:composer/quellabs/canvas-payments-klarna
Requires
- php: ^8.2
- ext-curl: *
- quellabs/canvas-payments-contracts: *
- quellabs/contracts: *
- quellabs/support: *
- symfony/http-client: *
README
A Klarna payment provider for the Canvas framework. Part of the Canvas payments ecosystem.
Installation
composer require quellabs/canvas-payments-klarna
Architecture
This package sits between the Klarna API and your application. Your application only ever touches the contracts
layer — it never depends on this package directly. PaymentRouter (from quellabs/canvas-payments) discovers this
package automatically via composer metadata and routes payment calls to it.
Your Application
│
▼
PaymentRouter (quellabs/canvas-payments — discovery + routing)
│
▼
PaymentInterface (quellabs/canvas-payments-contracts)
│
▼
Klarna (this package — implements the interface)
│
▼
KlarnaGateway (raw Klarna API calls)
Exchange processing is decoupled from your application via signals. When the buyer returns from the Klarna hosted
page, the package emits a payment_exchange signal carrying a PaymentState. Your application listens for that
signal and handles it.
Configuration
Create config/klarna.php in your Canvas application:
return [ 'api_username' => '', // Klarna API username from merchant portal 'api_password' => '', // Klarna API password from merchant portal 'test_mode' => false, // true → Playground, false → production 'return_url' => 'https://example.com/order/thankyou', 'cancel_return_url' => 'https://example.com/order/cancelled', 'default_currency' => 'EUR', 'default_country' => 'NL', 'locale' => 'nl-NL', 'place_order_mode' => 'CAPTURE_ORDER', ];
| Key | Required | Description |
|---|---|---|
api_username |
Yes | Username from Klarna merchant portal under Settings > API Credentials |
api_password |
Yes | Password from Klarna merchant portal under Settings > API Credentials |
test_mode |
No | Routes to the Klarna Playground environment when true. Defaults to false |
return_url |
Yes | Buyer is redirected here after a completed payment |
cancel_return_url |
Yes | Buyer is redirected here after a cancelled, failed, or errored payment |
default_currency |
No | ISO 4217 currency code used when none is specified on the request. Defaults to EUR |
default_country |
No | ISO 3166-1 alpha-2 country code used when no billing address is provided. Defaults to NL |
locale |
No | BCP 47 locale for the Klarna checkout UI. Defaults to nl-NL |
place_order_mode |
No | CAPTURE_ORDER for digital goods, PLACE_ORDER for physical goods. Defaults to CAPTURE_ORDER |
CAPTURE_ORDER means Klarna captures payment automatically on authorisation — no further action needed.
PLACE_ORDER means you must manually capture via the Klarna Order Management API after shipping.
Important: storing the order reference
The Klarna order_id is delivered via the payment_exchange signal in PaymentState::$metadata['paymentReference'].
Store this against your order — it is required for refund calls and for reconciliation.
Supported payment modules
| Module name | Description |
|---|---|
klarna |
All Klarna payment methods — Klarna selects based on context |
klarna_paynow |
Pay now — immediate payment |
klarna_paylater |
Pay later — invoice, pay after delivery |
klarna_sliceit |
Slice it — installment financing |
Available payment options are determined by Klarna at checkout based on the buyer's country, order amount, and risk assessment. There is no issuer pre-selection.
Usage
Initiating a payment
use Quellabs\Payments\Contracts\PaymentInterface; use Quellabs\Canvas\Controllers\BaseController; use Quellabs\Payments\Contracts\PaymentRequest; use Quellabs\Payments\Contracts\PaymentAddress; use Quellabs\Payments\Contracts\PaymentInitiationException; class CheckoutController extends BaseController { public function __construct(private PaymentInterface $router) {} /** * @Route("...") */ public function checkout(): Response { $request = new PaymentRequest( paymentModule: 'klarna', amount: 999, // in minor units — €9.99 currency: 'EUR', description: 'Order #12345', billingAddress: new PaymentAddress( street: 'Damrak', houseNumber: '1', postalCode: '1012LG', city: 'Amsterdam', country: 'NL', givenName: 'Jan', familyName: 'de Vries', email: 'jan@example.com', ), ); try { $result = $this->router->initiate($request); $this->orderService->setTransactionId($orderId, $result->transactionId); return $this->redirect($result->redirectUrl); } catch (PaymentInitiationException $e) { // handle error } } }
Providing a billing address is strongly recommended — Klarna uses it to pre-fill the checkout page and improve the authorisation rate.
Handling refunds
use Quellabs\Payments\Contracts\RefundRequest; use Quellabs\Payments\Contracts\PaymentRefundException; // Full refund — pass null as amount $request = new RefundRequest( paymentReference: $state->metadata['paymentReference'], paymentModule: 'klarna', amount: null, // null = full refund currency: 'EUR', description: 'Full refund for order #12345', ); // Partial refund — provide amount in minor units (cents) $request = new RefundRequest( paymentReference: $state->transactionId, paymentModule: 'klarna', amount: 500, // €5.00 currency: 'EUR', description: 'Partial refund for order #12345', ); try { $result = $this->router->refund($request); } catch (PaymentRefundException $e) { // handle error }
Listening for payment state changes
use Quellabs\Canvas\Annotations\ListenTo; use Quellabs\Payments\Contracts\PaymentState; use Quellabs\Payments\Contracts\PaymentStatus; class OrderService { /** * @ListenTo("payment_exchange") */ public function onPaymentExchange(PaymentState $state): void { match ($state->state) { PaymentStatus::Paid => $this->markPaid($state->transactionId, $state->valuePaid), PaymentStatus::Canceled => $this->markCanceled($state->transactionId), PaymentStatus::Failed => $this->markFailed($state->transactionId), PaymentStatus::Expired => $this->markExpired($state->transactionId), default => null, }; } }
Reconciliation
If the buyer closes the browser before being redirected back, your order may remain in a pending state. Implement a reconciliation job for orders stuck in pending beyond a reasonable threshold (e.g. 15 minutes):
// Pass the order_id stored from metadata['paymentReference'] on the first successful exchange $state = $this->router->exchange('klarna', $order->paymentReference); $this->onPaymentExchange($state);
License
MIT