Accept Unzer Bank Transfer with a server-side-only integration
Build your own payment form to add Unzer Bank Transfer payment to the checkout page
Overview
The customer can use Unzer Bank Transfer to conveniently pay using their own banking network. After selecting Unzer Bank Transfer as a payment method, they are redirected to our PIS (Payment Initiation Service) endpoint where they can authorize the payment.
Before you begin
- Check the basic integration requirements.
- Familiarize yourself with the general Server-side-only integration guide.
Step 1: Create a payment type resource server side
When creating the payment type Unzer Bank Transfer, you need to send a request to the Unzer API. The response contains an id
, this is later referred to as typeId
. You will need this typeId
to perform the transaction.
POST https://api.unzer.com/v1/types/pis
Body: {}
$unzer = new UnzerSDK\Unzer('s-priv-xxxxxxxxxx');
$pis = new UnzerSDK\Resources\PaymentTypes\PIS();
$pis = $unzer->createPaymentType($pis);
Pis pis = new Pis();
Unzer unzer = new Unzer(new HttpClientBasedRestCommunication(), "s-priv-xxxxxxxxxx");
pis = unzer.createPaymentType(pis);
The response looks similar to the following example:
{
"id": "s-pis-ynkylhm788ro",
"method": "PIS",
"recurring": false,
"geoLocation": {
"clientIp": "127.0.0.1",
"countryCode": "DE"
}
}
For more details on Unzer Bank Transfer payment type creation, see API reference.
Step 2: Make a payment server side
Make a charge transaction
Now, make a charge
transaction with the FlexiPayDirect
typeId
that you created and the returnUrl
leading back to your shop after the payment is finished on the external page. With the charge
transaction, an amount is requested but is not yet transferred. Initially, the transaction is pending and a payment
resource is created.
POST https://api.unzer.com/v1/payments/charges
{
"amount" : "20",
"currency": "EUR",
"returnUrl": "https://www.my-shop-url.de/returnhandler",
"resources" : {
"typeId" : "s-pis-jldsmlmiprwe"
}
}
$unzer = new Unzer('s-priv-xxxxxxxxxx');
$unzerBankTransfer = $unzer->fetchPaymentType('s-pis-0ajzmaxcuvhc');
$charge = $unzerBankTransfer->charge(20.0, 'EUR', 'https://www.my-shop-url.de/returnhandler');
Unzer unzer = new Unzer("s-priv-xxxxxxxxxx");
Charge charge = unzer.charge(BigDecimal.ONE, Currency.getInstance("EUR"), "s-pis-0ajzmaxcuvhc", new URL("https://www.my-shop-url.de/returnhandler"));
The response looks similar to the following example:
{
"id": "s-chg-1",
"isSuccess": false,
"isPending": true,
"isError": false,
"redirectUrl": "https://payment.unzer.com/v1/redirect/pis/s-sGYdGywWpxzW",
"message": {
"code": "COR.000.100.112",
"merchant": "Request successfully processed in 'Merchant in Connector Test Mode'",
"customer": "Your payments have been successfully processed in sandbox mode."
},
"amount": "20.0000",
"currency": "EUR",
"returnUrl": "https://www.my-shop-url.de/returnhandler",
"date": "2021-05-10 00:51:03",
"resources": {
"paymentId": "s-pay-131937",
"traceId": "70ddf3152a798c554d9751a6d77812ae",
"typeId": "s-pis-jldsmlmiprwe"
},
"paymentReference": "",
"processing": {
"uniqueId": "31HA07BC8157BD2BC04D483EFA914465",
"shortId": "4845.3426.1987",
"traceId": "70ddf3152a798c554d9751a6d77812ae"
}
}
For a full description of the charge
transaction, refer to the relevant server-side integration documentation page: Charge a payment (direct API calls), Charge a payment (PHP SDK), Charge a payment (Java SDK).
Forward the customer to external payment page
After you charge the FlexiPayDirect
resource, implement the following flow:
- Forward the customer to the
redirectURL
returned in the response to yourcharge
request. - The customer is forwarded to the Unzer Bank Transfer payment page.
- After a successful payment or abort on the pis page, the customer is redirected to the
returnURL
specified in the initialCharge
call.
Step 3: Check status of the payment server side
Once the customer is redirected to the returnUrl
, you can fetch the payment details from the API, by using the resources.paymentId
from the charge response above to handle the payment according to its status. If the status of the payment is completed
, the payment process has been finished successfully and can be considered as paid. You can check all the possible payment states here.
GET https://api.unzer.com/v1/payments/{resource_ID}>/charges/{transaction_ID}
{
"id": "s-pay-131937",
"state": {
"id": 1,
"name": "completed"
},
"amount": {
"total": "20.0000",
"charged": "20.0000",
"canceled": "0.0000",
"remaining": "0.0000"
},
"currency": "EUR",
"orderId": "",
"invoiceId": "",
"resources": {
"customerId": "",
"paymentId": "s-pay-131937",
"basketId": "",
"metadataId": "",
"payPageId": "",
"traceId": "70ddf3152a798c554d9751a6d77812ae",
"typeId": "s-pis-grpucjmy5zrk"
},
"transactions": [
{
"date": "2021-05-10 00:51:03",
"type": "charge",
"status": "success",
"url": "https://api.unzer.com/v1/payments/s-pay-131937/charges/s-chg-1",
"amount": "20.0000"
}
]
}
Step 4: Display the payment result client side
Use the information from the Check status of the payment step to show payment result to your customer.
This can be the success or error page of your shop. If something went wrong you can use the client message from the API response and show it to the customer.
Manage payment server side
For more details on managing Unzer Bank Transfer payments, such as refunding them, see Manage Unzer Bank Transfer payments
Notifications
We recommend subscribing to the payment
event to receive notifications about any changes to the payment
resource. As soon as the event is triggered you should fetch the payment
and update the order status in your shop according to its status.
{
"event":"payment.pending",
"publicKey":"s-pub-xxxxxxxxxx",
"retrieveUrl":"https://api.unzer.com/v1/payments/s-pay-774",
"paymentId":"s-pay-774"
}
For more details on implementing webhooks
to receive notifications, see Notifications page.
Error handling
All requests to the API can result in an error that should be handled. Refer to the Error handling guide to learn more about Unzer API (and other) errors and handling them.
Test & go live
You should always test your integration before going live. First perform test transactions using test data. Next, check against Integration checklist and Go-live checklist to make sure the integration is complete and you’re ready to go live.