FHIR Topic-Based Subscription Tools

This is a general overview page for the software hosted at subscriptions.argo.run, which can be used to test topic-based subscription in FHIR R4 (via the Backport IG) and FHIR R5.

If you have any comments or questions, feel free to ping me on Zulip.

Overview

There are three main projects which together implement the entire Subscriptions workflow:

• A C# FHIR Server Proxy
  • Interacting in R4 via Backport IG
  • Interacting in R5
• A React/TypeScript Client
• A C# Endpoint Hosting Server

Additionally, there are two basic client projects to serve as examples:

• A C# Client
• A Node/JS Client

Links

Projects are currently running from CI builds.

FHIR R4B + Backport IG

• Implementation Guides
  • Subscription Backport IG
• FHIR Resources
  • SubscriptionTopic
  • Subscription
  • SubscriptionStatus
  • Bundle (type: history)

FHIR R5

• Implementation Overview
  • Subscriptions Framework
• FHIR Resources
  • SubscriptionTopic
  • Subscription
  • SubscriptionStatus
  • Bundle (type: subscription-notification)

The supported SubscriptionTopic for testing is based on the Argonaut 2019 Subscriptions work:

• Draft Encounters IG
  • Canonical SubscriptionTopic: encounter-start

Components

FHIR Server Proxy

• GitHub Repo
• Azure Hosted URL: server.subscriptions.argo.run (FHIR R4 Endpoint)

The Server Proxy is a thin server layer over a standard FHIR server, which intercepts resources needed to support subscriptions:

• Subscription
• SubscriptionTopic
• Encounter

When using the server, all resources are formatted according to the FHIR version for that endpoint (e.g., the FHIR R4 endpoint uses Subscriptions, SubscriptionTopics, Encounters, Patients, etc. in FHIR R4).

Client

• GitHub Repo
• Azure Hosted URL: subscriptions.argo.run (Web Page)

The Client has been written to be as self-contained as possible. The major issue with running the client a web-browser is that it cannot host REST endpoints. Instead, the client connects to the Endpoint Host via Websockets and receives notifications from there.

Since the client is in the browser and the Endpoint Host is public, you can use the client to test against locally hosted servers.

Client Tab: Config

• Settings (e.g., URLs, light/dark look, etc.)
  • FHIR Server URL can be set to your test URL
  • Again, since everything runs in the browser, it can point to localhost, etc.
  • The “Use Backport to R4” setting turns on/off using the R4 Backport instead of R5
  • Connecting gets the Capabilities Statement and checks for needed capabilities based on the operations in the UI
  • If you are having trouble connecting to your server, turn on the ‘Skip FHIR Server Capabilities Check’ toggle
• Useful links (e.g., to the current and previous Connectathons, to the GitHub repos of this software, etc.)
• Connect/Disconnect button: connect to the server and client host (required for all other operations)

Client Tab: Patient + REST

• Walks through a single-patient encounter notification and REST notifications
• “On Rails” guided version, only options available are valid for the scenario

Client Tab: Group + REST

• Same as above, but uses the Group resource for filtering events instead of Patient directly

Client Tab: Playground

• Named appropriately :-)
• Allows for testing of things like Websockets, Email, etc.

Endpoint Hosting Server

• GitHub Repo
• Azure Hosted URL: client.subscriptions.argo.run (Web API)

The Endpoint Hosting Server is a host that interacts with a Client via Websockets to host public-accessible HTTP/S endpoints. It is only useful in the context of the Client, so may generally be ignored.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

There are many other ways to contribute:

• Submit bugs and help us verify fixes as they are checked in.
• Review the source code changes.
• Engage with users and developers on Official FHIR Zulip
• Contribute bug fixes.

See Contributing for more information.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

FHIR® is the registered trademark of HL7 and is used with the permission of HL7.