This implementation guide describes a FHIR API that allows interaction with the Ontario Benefit Program Client Services (BPCS) system. Using the API, authorized client applications can query, create and update relevant records in support of BPCS business functions.

This FHIR API acts as a fa├žade over a legacy application. Because of this, functionality is constrained by the capabilities of that existing back-end system. Some of the functionality is surfaced as FHIR operations and named queries, or tight restrictions on standard RESTful interactions due to the limitations on the types of searching and data manipulation allowed, as well as the need to sometimes pass multiple resources as input to a business function. That said, FHIR design principles have been adhered to as much as possible and pure REST interactions are used where existing system functionality aligns.