Technical Specifications > Technical Background


This IG uses two different FHIR based integration methods to provide standard, non-proprietary ways for different systems that participate in electronic referrals (eReferrals) to interoperate with one another.

  • FHIR messaging provides a standard way for a software application to transmit information directly to other trusted applications using a backend FHIR API. In this IG, FHIR Messaging is the basis of Direct Messaging integrations that connect RMS systems and referral networks to one another.

  • The SMART App Launch Framework (SMART on FHIR) provides a standard way for a software application to allow a user to securely launch another "app", with context (user and patient), using FHIR, the OAuth2 Authorization Framework, OpenID Connect and a lightweight web browser based user interface (UI) integration. In this IG, SMART on FHIR is the basis of SMART integrations that allow healthcare practitioners and service providers to access RMS Systems, specialized functionality and corresponding referral networks in a user friendly way.

Underlying technologies

The integration methods and patterns in this IG are based on the HL7 FHIR standard. As a result, this IG uses terminology, notations and design principles that are specific to FHIR. Readers who are unfamiliar with FHIR are encouraged to read (or at least skim) the following prior to reading the formal specifications for Direct Messaging and SMART integrations in this implementation guide.