Da Vinci Health Record Exchange (HRex)
1.1.0-preview - STU R1 United States of America flag

Da Vinci Health Record Exchange (HRex), published by HL7 International / Clinical Interoperability Council. This guide is not an authorized publication; it is the continuous build for version 1.1.0-preview built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/davinci-ehrx/ and changes regularly. See the Directory of published versions

Tooling and Support

Page standards status: Informative

FHIR provides many supports to aid in its implementation. This page describes some of them.


The most important resource for implementing FHIR is the FHIR community, and the best place to engage the FHIR community is on chat.fhir.org. That website is a multi-threaded discussion forum covering a wide range of implementer topics. There are numerous streams specific to various Da Vinci projects, as well as streams on technologies and specifications such as Bulk Data, CDS Hooks, etc. A search in the appropriate stream will often find an answer to your question and, if not, post a new question and you will likely get a speedy answer.

Reference implementations

FHIR has been implemented in a variety of languages. For most of these languages, free open-source reference implementations are available. This standard software handles parsing and serializing all the formats, exposing FHIR instances as language-friendly object representations, handles making RESTful calls, and otherwise dealing with the low-level implementation of the standard. By using reference implementations, implementers can focus on business logic and other application-specific software, relying on well-tested shared libraries to handle the FHIR-specific behavior.

A list of FHIR reference implementations can be found here.


One of the benefits of using FHIR is that the rules that define how instances must look that are rendered in the specification are expressed in computable form - which means that software can evaluate instances to verify whether they comply with profiles defined in a published implementation guide. This software can do more than typical XML and JSON schema validation - they can check complex invariants, verify terminology, resolve references, and check most of the rules documented in the specification. As a result, human review and testing can be limited to those few things that the validator cannot test.

The current version of the FHIR Validator can be found here. (It changes regularly to fix bugs and add enhancements, so plan to update regularly.)

Guidance on using it is found here.