This section details the “Messaging Architecture” used for ITK3 using FHIR messaging and documents such as:

• The different types of bundle structures which may be used
• Identifying the FHIR Resources which are Profiled
• Providing example bundle instances
• Explaining the extensions to the header Resource for ITK3 Handling Specifications

Pre-Requisites for FHIR ITK3 Messaging Solutions

There are some pre-requisites for the use of the ITK3 Messaging Distribution specification which are detailed below.

ITK3 Messaging Distribution Requirements

• SHALL support HL7 FHIR STU3.
• SHALL implement ITK3 Sender and/or Receiver Responsibilities as per ITK3 Document Sender and Receiver Requirements when sending an ITK3 FHIR Document.
• SHALL support the XML format for all NHS Digital document and message flows.

FHIR Conformance

Systems SHOULD declare a Conformance using the FHIR Resource Capability Statement identifying the list of message definitions supported.