Firely is the original author and main contributor of the official FHIR HL7 reference implementation API for Microsoft .NET. The open source library has been downloaded and used tens of thousands of times by developers around the world.

Running within an hour

The Firely FHIR products Simplifier, Forge and Spark are based on the library as well. Download the NuGet packages of the API and you’ll have your first FHIR client running within an hour.

The library

The library includes classes for serialization and deserialization to XML and JSON, defining server calls (including search commands), setting up complex resource resolving scenarios, snapshot generation, validation and caching.

FHIR compliancy guaranteed

The .NET API is typically used by .NET developers who want to build their own FHIR client, server or add-on and who want to be sure to be FHIR compliant without having to implement the basis and more advanced FHIR features themselves.

The source code is available on GitHub. Contributions to the open source library are welcome. Just send us a pull request.

  • At NHS Digital we highly appreciate the work that Firely has done for the FHIR community with their open source .NET library. We use the library in our own tooling and have contributed to parts of the library. It is clearly one of the leading libraries in FHIR.

    Head of Interoperability Data Architecture

    NHS Digital – United Kingdom