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    Getting started

    This page shows how to get started using and integrating Relay services and what agreements and credentials you might need before you can use Relay services.


    What you need before you start:

    If you haven't yet, please contact our Customer Service to learn about necessary contracts and access keys. Before you start, you also should have received the .proto files from us.


    Relay services

    Relay API is a collection of various gRPC services. You as a platform can use it to provide your merchants with additional payment methods and payment processing services.

    Relay services include for instance:

    • Notification Service: subscribe to specific notifications through a variety of channels (webhooks, for instance). To subscribe to specific notifications is a requirement for using other services. You MUST set these subscriptions as an initial step.

    • Merchant Service: Lets you create merchants in our database. If successful, you'll receive a merchant_id which you will need so that you can use our services for that specific merchant.

    • Enrollment Service: Used to add one or more payment methods for a specific merchant. Check the list of payment service providers we're partnering with and the related available payment methods here.

    • Processing Service: Used to process payments for a specific merchant.


    Relay services use the gRPC (Remote Procedure Call) framework. Definitions and requirements of calls to our server are defined through HTTP/2 Protocol Buffers (.protobuf files). Find the service definitions in our API Reference.

    Protocol Buffers

    All Relay services and the corresponding operations are defined as Protocol Buffer definitions in the corresponding .proto files. You receive this files from us. Depending on the coding language you are using, there are usually packages available, to get these Protocol Buffers imported into your code.

    The messages determine the fields and the expected types for the defined keys.

    Our API Reference section gives a comprehensive overview of these .proto definitions.


    Each of these services provides several methods. For example, the Merchant Service consists of:

    • Create - creates a merchant entry on our side and returns a merchant_id
    • Update - allows you to update data that has been stored according to the merchant_id.
    • Get - allows you to get all the stored data for that merchant_id

    Request and response

    Each of these procedures consists of a request call and a response.


    Depending on your specific use case, you can combine calls to various methods from different services to accomplish specific tasks.


    If, for example, you want to enable an additional payment method for a merchant you should:

    • Create the merchant (if he does not exist in our system already), using the Merchant Service's Create operation.
    • Enroll the desired payment method, using the Entrollment Service's Enroll operation.

    This guide will introduce you to some possible tasks and the corresponding succession of calls you SHOULD send.


    Integration of gRPC services usually starts with importing the .proto files into your code. Depending on your coding language, there are usually packages available for that.

    Before you start using our Relay services, you MUST enable notifications as described here.

    A third step that is required for any actions you might want to take is to create the merchant, which means to send the required merchant data to us and receive a merchant_id in return.

    Once that is accomplished, you can start performing actions for that merchant, such as to enable the merchant for additional payment methods and to process these payments.

    Next: Set up Notifications