FIRELY .NET SDK formerly .NET FHIR API
The official HL7 FHIR SDK in .NET
Drive health interoperability and save precious development time with Firely’s open-source FHIR SDK

Get a running start in implementing FHIR the right way
Fully compliant to the latest HL7 FHIR standard
Firely is the original author and main contributor of the official HL7 FHIR reference implementation for Microsoft .NET.
Speed up implementation time
Download the NuGet packages of the SDK and you’ll have your first FHIR client running within an hour.
Open-source and trustworthy SDK
The open source library has been downloaded millions of times by developers around the world.
Lower the amount of coding for your team
Build your own FHIR client, server or add-on without having to implement all the basic and advanced FHIR features from scratch.
Get started today
Key features
Unleash the power of your data

- Serialization and deserialization to XML and JSON
- Snapshot generation, validation and caching
- Set up complex resource resolving scenarios
Bring into play for Interoperability and Patient Access Rules
ONC Cures Act
Achieve stress-free compliance with
our FHIR Server, FHIR SDK and FHIR
training courses.
CMS Final Rule
Implement a Patient Access API or
your FHIR API-based Provider
Directory with Firely.
Trusted by leading companies and thousands of developers
Want to know more about the Firely .NET SDK?
Get in touch for more information.
Check out more products from our FHIR suite
R on FHIR
Easily run R scripts against your FHIR server for powerful research and analytics
Firely Terminal
formerly Torinox
Build automation pipelines with our cross-platform Command Line Tool for FHIR.
WindTunnel
Test your FHIR Server and guarantee high-quality performance, one release after another
Find out how Firely can help you bring FHIR to life
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