Operating the Nexus Gateway

The Nexus Gateway is a software component which coordinates processes such as cross-border proxy resolution, FX quoting and conversion, messaging, the sequencing of payments between two countries and the reversal of failed payments.

Each IPSO will install and run their own instance of the Nexus Gateway software. Each Gateway connects to the domestic IPS infrastructure on one side and to Nexus Gateways in other countries on the other side.

Setting up reference data via the Reference Data Service

An IPSO must provide the Nexus Gateway with certain reference data. This information can be provided via:

  • The browser-based administration portal

  • The Nexus APIs (using credentials with appropriate permissions for the IPSO)

The reference data includes:

  • The Unique Payment Systems (a unique combination of an IPS and a currency) that this IPSO is responsible for

  • The permitted addressing formats for this IPS (such as IBAN and/or local account formats and financial institution identifier formats)

  • Any proxy (alias) schemes available in the IPS’s jurisdiction (to which Nexus participants can connect), and the proxy formats that they support (eg email, phone number)

  • All member PSPs in the IPSO, including those that are not onboarded with Nexus, and whether each PSP is onboarded with Nexus or not.

Where this data is required by other Nexus participants (eg PSPs in other countries) the local Nexus Gateway will automatically synchronise this data to all Nexus Gateways. (In practice, most reference data is synchronised to every other Gateway, although some data points are only required for internal processing.)

Communication with PSPs and SAPs

There are two models for a PSP to communicate with the Nexus Gateway, depending on the local IPS implementation:

  • Via the IPS: All communication will go through the existing secure connection between the PSP and the IPS. The IPS can provide pass-through APIs that forward requests to the local Nexus Gateway APIs (and vice versa).

  • Via a common shared network: Where a secure network exists between all PSPs and the IPSO, the IPSO may request PSPs communicate directly with the Nexus Gateway. In this case, the local Nexus Gateway would have its own identifier or address on the secured network.

Nexus Gateways will also support communication through message queues where this is used by the IPS and PSPs.

Communication with FXPs

An FXP can connect to any Nexus Gateway. The FXP should choose the one most convenient for them and then consistently communicate with that chosen Gateway. Their choice could be based on jurisdiction, geographical location, membership of the same secure network, or any other consideration.

Upon instruction by the NSO, the IPSO should issue an FXP with API credentials to connect to that Gateway.

The Gateway will ensure that any data generated in response to the FXP’s API calls will be distributed to the appropriate Gateways in the Nexus network.

Communication with Proxy Lookup Services

The Nexus expects the IPSO (as operator of the Nexus Gateway) to take on the responsibility for connecting the local Nexus Gateway to the domestic Proxy Lookup Service(s) (PLS) operator, particularly where:

The IPSO and the PLS Operator are the same entity, AND/OR

In the country where the IPSO provides payment services to, there is only one PLS operator

The Nexus Gateway will allow the IPSO to add API credentials for the Proxy Lookup Service Operator. The Gateway can then communicate directly with the PLS to make proxy resolution requests on behalf.

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