Table of Contents

  1. Introduction
  2. Documentation Resources
  3. Main Inferno Repositories
  4. Inferno Test Kits
  5. Contact the Inferno Team


Inferno is a framework for creating, executing, and sharing tests for health IT systems providing standardized FHIR APIs. You use Inferno to create Inferno Test Kits which are standalone, portable test applications that are tailored to test specific FHIR-enabled data exchange use cases as described in FHIR Implementation Guides.

Examples of test applications (Test Kits) built using Inferno include:

Each of these Test Kits is a standalone application that can be run on an end user’s machine, on a shared private host behind a firewall, or on a shared public host such as inferno.healthit.gov. They are Ruby applications built with the Inferno Core gem which provides several features useful for a FHIR testing application:

  • Inferno DSL: A domain specific language for authoring FHIR API tests that includes a FHIR client, native Ruby classes for FHIR, and FHIR instance validators
  • API, Web and CLI Interfaces: Multiple interfaces for executing tests and retrieving results
  • Test Reuse: Methods for reusing tests within a project or from other projects

Inferno’s design reflects the flexibility provided by the base FHIR specification. As a platform specification that is intended to provide support across the whole healthcare process, FHIR relies on Implementation Guides to provide enough specificity to enable meaningful interoperability between actors for a given data exchange use case. FHIR Implementation Guides typically will describe how to use relevant portions of the FHIR specification for its use case, while also providing additional rules that are not described within FHIR itself. There are no limits to what these rules may include, and may even require the use of other standards, such as OAuth or QR Codes for Vaccination Credentials, as part of their conformance criteria.

Creating a test system that is flexible enough to test any arbitrary conformance criteria introduced in Implementation Guides is challenging. Inferno accomplishes this by providing test authors with a full featured Ruby programming environment to define and run their tests, and doesn’t restrict usage of the rich ecosystem of open source third-party libraries provided by Ruby. This makes Inferno well-suited for testing Implementation Guides that:

  • include the use of additional standards beyond FHIR,
  • have large specifications that could benefit from Ruby’s meta-programming capabilities to ease maintenance burden,
  • or require complex logic to thoroughly validate API responses.

Inferno Core provides common utilities for FHIR-based testing, but tests are not limited to what is provided by Inferno Core. Inferno Core’s goal is to expand on the set of common utilities it provides for the benefit of the community.

While Ruby is sufficient for most testing needs, Inferno Test Kits may also include components that are not defined in Ruby. Inferno Test Kits can include other non-Ruby services as needed, and by default provides a Docker Compose configuration to run and integrate with these services from within Inferno’s testing DSL.

Documentation Resources

Main Inferno Repositories

  • Inferno Core - The Inferno ruby library itself. This repository contains the code for defining and running tests, the command line and web interfaces, and this documentation. This is the repository to use if you want to investigate or make changes to the internals of Inferno.
  • Inferno Template - A template for test writers. This is the repository to use if you want to write your own set of tests with Inferno.
  • FHIR Validator Wrapper - A simple web wrapper around the official HL7 FHIR validation library. Inferno relies on this service to validate FHIR resources.

Inferno Test Kits

See available Test Kits

Contact the Inferno Team

The fastest way to reach the Inferno team is via the Inferno Zulip stream. You can also e-mail the team.