Page Comparison

Restful APIs

The API adheres to RESTful API concepts where possible and sensible to do so.

However, the priority is to have an API that is simple to understand and easy to use. In instances where following RESTful principles would be convoluted and complex, the principles have not been followed.

References:

• The highest level Data Description Language used is the JSON Schema : http://json-schema.org/

• Best Practice has also been taken from the Data Description Language for APIs; JSON API : http://jsonapi.org/

• The Interface Description Language used is the Swagger Specification version 3.0.0 (also known as Open API) : http://swagger.io/

ISO 20022

In keeping with that requirement, the API payloads are designed using the ISO 20022 message elements and components where available.

The principles we have applied to re-use of ISO message elements and components are:

• Only elements that are required for the functioning of the API endpoint will be included in the API payload. API endpoints are defined for specific use-cases (not to be generically extensible for all use-cases).

• We will modify ISO 20022 elements where the existing standard does not cater for an API context (such as filtering, pagination etc.).

The functionality, endpoints and fields within each resource are categorised as 'Mandatory', 'Conditional' or 'Optional'.

Mandatory

Functionality, endpoints and fields marked as Mandatory are required in all cases for regulatory compliance and/or for the API to function and deliver essential customer outcomes.

For functionalities and endpoints:

• An ASPSP must implement an endpoint that is marked Mandatory.

• An ASPSP must implement functionality that is marked Mandatory.

For fields:

• A AISP/PISP must specify the value of a Mandatory field.

• An ASPSP must process a Mandatory field when provided by the AISP/PISP in an API request.

• An ASPSP must include meaningful values for Mandatory fields in an API response.

Conditional

Functionality, endpoints and fields marked as Conditional may be required in some cases for regulatory compliance (for example, if these are made available to the USER/CUSTOMER in the ASPSP's existing Online Channel, or if ASPSPs (or a subset of ASPSPs) have been mandated by a regulatory requirement).

For functionalities and endpoints:

• An ASPSP must implement functionality and endpoints marked as Conditional if these are required for regulatory compliance.

For fields:

• All fields that are not marked as Mandatory are Conditional.

• A AISP/PISP may specify the value of a Conditional field.

• An ASPSP must process a Conditional field when provided by the AISP/PISP in an API request, and must respond with an error if it cannot support a particular value of a Conditional field.

An ASPSP must include meaningful values for Conditional fields in an API response if these are required for regulatory compliance.

Optional

Functionality and endpoints marked as Optional are not necessarily required for regulatory compliance but may be implemented to enable desired customer outcomes.

For functionalities and endpoints:

• An ASPSP may implement an Optional endpoint.

• An ASPSP may implement Optional functionality.

For fields:

• There are no Optional fields.

For any endpoints which are implemented by an ASPSP, the fields are either Mandatory or Conditional.