Plugin Development


Before you start developing you need a few things...

  • Payrexx account: Signup here

  • A fully set up payment provider which fits your needs: PSP Features

  • API credentials: Find them in your Payrexx account under API & Integration


Plugin Standards


Payment Methods

The payment method selection should take place in the shop system. Therefore all payment methods should be individually activatable in the plugin.

If this is not possible at least offer an icon selection so the merchant can show their customer which payment method selection awaits them after redirecting to Payrexx. We provide a repository containing the payment method logos which are free to use for commercial purposes.

API Credentials

It should be possible to check if the instance name and API key have been set correctly. Use the Signature Check endpoint to do so.

Data Transmission

Try to transmit as much data to Payrexx as possible.

This ensures the relation from the Payrexx transaction to the shop order. Also the payment process is simplified for the end customer. For example, some payment methods expect an address for a credit check. The end customer should not have to enter this twice.

Here's a small checklist on what should be transmitted:

  • Required data

    • Amount (Make sure this matches the total of all basket products added!)

    • Currency

    • ReferenceId (Order ID)

  • Customer data

    • Email

    • Full name & address

  • Shopping cart

    • Product names, SKU, price, description

    • Shipping costs

    • Possible discounts

    • Possible fees


Every plugin needs to be able to process Payrexx webhooks. This ensures the synchronisation of the transactions status with the order payment status.


Every plugin needs to feature some configuration possiblities.

Required informations:

  • Instance name (Payrexx account name)

  • API Key

Without this data no API requests can be processed.

Additional informations:

  • Look & Feel ID

  • Prefix (This is added to the reference so multiple shops can be distinguished)

Look & Feel ID is used to use the correct Look & Feel in the checkout. This is especially useful if a merchant wants to have multiple webshops while using one Payrexx account.


The customer is done with the checkout process and now wants to pay.

You need to create a Payrexx Gateway and redirect your customer to the payment form. Follow the link below for a full manual which explains the Payrexx Gateway and how to use it:

Build Your Gateway

Transaction Feedback

It is crucial to always know what the status of a transaction is. The shop must be informed whether a transaction has been successfully completed or cancelled.

This can be done using the Payrexx webhooks. A webhook sends all transaction data on every transaction status change to a given URL.

Find out how the webhooks work in our Webhook Guide:


Additional Information

There are already plugins available for some shopsystems. The sourcecode of these plugins is open source and might help you develop your plugin.

Shop system plugins:

We are here to help if you have any development questions.

Just contact us at

Last updated