The official open-source Firely .NET SDK

FHIR API illustration
  • Open-source
  • Fully compliant with the standard
  • Speeds up implementation time
  • Lower the amount of coding


Get a running start in implementing FHIR the right way

Firely .NET SDK icon


Drive health interoperability and save precious development time with Firely’s open-source FHIR Software Development Kit

Icon SDK libraries


Besides the main library, our Firely .NET SDK offers a CQL engine, FHIR Packages and Validation

Icon implement SDK


Use our expertise and best practices to smoothen your implementation project.

About Firely .NET SDK

Firely .NET SDK provides a set of tools and libraries that make it easier for developers to work with FHIR resources in .NET applications. It’s open source and can be downloaded from the GitHub repository. It is regularly updated to keep up with the latest developments in the FHIR standard.

Icon RESTful API


A client library for interacting with FHIR servers using the FHIR RESTful API. Easily retrieve, create, update, and delete FHIR resources using standard HTTP methods.

Icon FHIR data model

FHIR Data Model

Easier to work with FHIR resources in .NET applications because of the classes and interfaces that represent the different types of FHIR resources.

Icon Seriaization


Tools for serializing and deserializing FHIR resources in different formats, including JSON and XML

Icon FHIR profiling


Working with FHIR profiles, including the ability to create profiles with the SnapshotGenerator. Define custom profiles, and use them to validate resources against custom constraints.

Icon Multiple FHIR versions

Support for multiple FHIR versions

Work with any version of the FHIR standard, from the earliest releases to the latest and most cutting-edge versions, and ensure that your applications will continue to work seamlessly as the standard evolves over time.

Icon FHIRPath


Perform complex searches and manipulations on FHIR resources to retrieve specific data elements or transform them into new representations.

Get started today!

Or select one of the earlier versions of the FHIR specification:

Additional libraries

Some features are too big to just include in our main library. We like to call them part of our .NET SDK, but technically you’ll find them on their own spot in NuGet and Github.

CQL Engine

Execute CQL and evaluate CQL logic in libraries on the .NET platform. Created in collaboration with NCQA and tested against HEDIS measures.

FHIR Packages

Manage FHIR resources, and organize them into logical groups and versions for easier management and sharing.


Validation of FHIR resources out of the box to ensure syntactical and semantical correctness.

Take care of your implementation

Great products deserve great implementations. Firely provides all the training you need to better understand and implement FHIR.

FHIR Training Courses and Workshops for Health IT Professionals

Firely is of the initiators of the FHIR standard. Our training courses are aimed at implementers. Learn today, apply tomorrow.

FHIR training courses and workshops

Find out how Firely can help you bring FHIR to life

Leave a message here and we’ll reply sooner than you think.