Resources for Developers
Use our practical resources for developers to get started right away.
Instructions for own integration
Learn how to receive one-time or recurring payments directly in your system, on your website, or through your app.
Payrexx is compatible with all popular shop systems and CMS.
Guide for developers of platforms and marketplaces
Find all necessary documentation and support to receive online payments on your platform or marketplace.
Frequently Asked Questions from Developers
Can I try Payrexx for free?
Yes, the first 30 days of the trial subscription are free. Simply sign up here and start. No credit card is required.
How do I test a first payment?
Enable the test mode in the payment provider settings. After that, you can open a payment page via API or one of the integrated tools and perform a test payment without any flow of money. More about this here
Which programming languages are supported?
You can use our API with any language. More information can be found in the Payrexx API Documentation.
For PHP, we also offer a ready-to-use SDK in our GitHub account.
Where can I find code examples?
In our PHP SDK, you will find ready-made PHP example codes for various use cases.
In the API documentation, you will find examples for each API call.
How are SCA (Strong Customer Authentication) and 3D Secure 2.0 handled in the checkout flow?
Payrexx automatically takes care of the complex requirements of the Payment Services Directive PSD2 (including SCA) for the developer.
For standard credit cards, the 3D Secure challenge flow is hosted and processed directly by the Payrexx Gateway.
For wallets like Google Pay or Click to Pay (Visa), Payrexx automatically uses modern, tokenized authentication methods (e.g., CRYPTOGRAM_3DS). Since this is already recognized as strong authentication by card issuers, the additional 3D Secure step in the checkout process is completely eliminated (Frictionless Flow).
Does the API support automatic processing of partial refunds?
Yes. Both full refunds (Refund) and partial refunds (Partial refund) are supported via API and in the Dashboard. The transaction object of the API also returns the Boolean values refundable and partiallyRefundable, so the developer's system immediately knows if a partial booking is possible. In the case of a partial collection refund, the status of the transaction changes to partially-refunded. Webhooks are also triggered on these status changes.
How is idempotency ensured in API calls to prevent duplicate transactions?
To avoid duplicate bookings, developers must use the unique Payrexx uuid (Transaction ID from Payrexx) or their own referenceId (Order ID of the shop) provided during transaction creation. Payrexx also recommends always matching webhooks against your own database using these IDs.
What PCI-DSS compliance requirements apply when using the API or SDKs?
Payrexx is certified as a payment platform PCI-DSS Level 1. When developers use the Payrexx Payment Gateway, the hosted payment pages (Pages) or plugins, their own servers do not come into contact with sensitive cardholder data (CHD - Cardholder Data). The entire sensitive payment flow is handled via Payrexx's servers, massively reducing the PCI compliance scope for the Händler (usually to a simple SAQ-A questionnaire).