- Home
- User Perspective Guides
- App Catalog Developers
App Catalog Developers
This page provides a high-level, App Catalog–developer-oriented overview of the HALO specification. It is designed as a starting point to help you navigate the most relevant sections, understand how App Catalogs enable consistent app discovery and launch across PoC systems, and identify the key requirements and conformance expectations for your role. It is not a substitute for the detailed implementation pages in the specification, but rather a directional guide to point you toward them.
Why HALO Matters to App Catalog Developers
By implementing a HALO-conformant App Catalog you deliver:
- Single source of truth for Apps – Provide PoC vendors with one authoritative registry of jurisdiction-approved SMART Apps, eliminating ad-hoc spreadsheets and manual whitelists.
- App discoverability – A consistent JSON schema and REST endpoint lets every PoC in your jurisdiction search, filter, and launch apps the same way.
- Streamlined App on-boarding – Standard metadata and scope declarations reduce back-and-forth with App publishers and accelerate security / privacy reviews.
- Context-aware launches – Publishing each app’s required SMART scopes enables PoC systems (and SoFA) to pre-populate only the data an app needs, improving performance and privacy.
- Governance & analytics – Centralized App approval, version tracking, and de-listing controls give jurisdictions confidence that only compliant, up-to-date apps are in use.
Key HALO Sections for App Catalog Developers
- Business Requirements – Understand the overarching requirements for App Catalog systems from a business lens.
- User Stories / Use Cases – Understand how the App Catalog supports clinical workflows by enabling PoC systems to surface relevant Apps, and how catalog metadata influences App discoverability and integration in care scenarios.
- Overall Architecture – Understand how your system fits into the broader HALO ecosystem and which systems you should expect to interact with.
- App Catalog – Understand the catalog’s JSON schema including required vs. optional fields, datatype constraints, and normative examples.
- App Launch – Understand how PoC systems use launchUrl, scopes, and other catalog metadata to form the launch request.
- Operation: $set-context – Required indirectly; PoC systems rely on the scopes element published in the App catalog to decide what context to send to SoFA.
- Subscriptions – Required indirectly; PoC systems rely on the scopes element published in the App catalog to determine what resources an App may create or modify.
- Privacy and Security Guidance – Review jurisdictional and national privacy and security guidelines, best practices, and legislative considerations to ensure your App Catalog meets applicable requirements for safeguarding patient data and supporting secure interoperability.
HALO conformance is comprised of several technical actors and transaction across several HALO Profiles. These responsibilities are grouped and tested leveraging the four core business use cases.
From the App Catalog perspective, the following use cases apply:
- UC-01: Care Provider views and selects SMART Apps that are of interest
Within this use case, App Catalog systems are responsible for fulfilling the App Catalog Supplier role and its related transactions.
For more details regarding testing and conformance expectations for App Catalog systems, see the Interoperability Recommendations and Technical Use Case Sequence Diagrams pages.
Responsibilities & Recommendations Checklist
App Catalog API
SMART App Registration
