AriaAPI

Version: 1.0.10

A .NET 10 class library providing a C# SDK for interacting with the Varian Aria oncology information system via its FHIR R4 API.

Requirements

• Varian Aria oncology information system with FHIR R4 API access
• OAuth2 client credentials (configured via .NET User Secrets)
• .NET 10 SDK

Features

• FHIR R4 resource search for 37 resource types (Patient, Appointment, Procedure, Observation, Encounter, ImagingStudy, and more)
• FHIR resource creation (DocumentReference, Task)
• OAuth2 client-credentials token management with in-memory caching
• Fluent builder pattern for constructing FHIR search queries
• Fan-out search for multi-valued FHIR parameters (OR within, AND across, deduplicated by Resource.Id)
• Multi-resource search helpers — cross-resource queries (PatientCareTeam, PatientEncounters, PatientObservations, PatientDocuments, PatientAppointments)
• FHIR Operations — $everything (PatientOperations) and $expand (ValueSetOperations)
• Write support — CareTeamWrite, AppointmentWrite with update/upsert and patient-centric overloads
• Identity resolution for Patients and Practitioners
• PHI-safe logging — all logged identifiers are SHA-256 masked (HIPAA)
• DI extension — IServiceCollection.AddAriaFhirClient(config) wires the full client stack
• Direct SQL queries against the Aria database (excluded from default build)
• Document generation workflows for Special Treatment Procedures (excluded from default build)

Quick Start

1. Register services (DI)

using AriaAPI.Networking.Helpers;

// In your Startup / Program.cs
services.AddAriaFhirClient(configuration.GetSection("FhirOptions"));

2. Search for a patient

using AriaAPI.API.SingleResourceSearch;

// Search for patients by name or identifier
var patients = await PatientSearch.PatientsAsync(
    configurator,
    new PatientSearch.PatientSearchParams { NameOrIdentifier = "Smith" });

3. Multi-resource search

using AriaAPI.API.MultiResourceSearch;

// Get a patient and their appointments within a date window
var (patient, appointments) = await MultiResourceSearch.PatientAndAppointmentsByDateAsync(
    configurator,
    patientIdentifier: "MRN12345",
    start: DateTimeOffset.Now.AddDays(-30),
    end: DateTimeOffset.Now);

4. Write a resource

using AriaAPI.API.Write;

// Update an existing appointment
var updated = await AppointmentWrite.UpdateAsync(configurator, appointment, logger);

Tech Stack

• .NET 10 (class library)
• Hl7.Fhir.R4 v6.0.1
• Microsoft.Extensions.DependencyInjection, Http, Caching.Memory
• Microsoft.Data.SqlClient v6.1.4 (excluded from default build)
• DocumentFormat.OpenXml v3.3.0 (excluded from default build)

Project Structure

AriaAPI/
├── API/
│   ├── Create/               # Resource creation (DocumentReference, Task)
│   ├── IdentityResolvers/    # Patient/Practitioner identity resolution
│   ├── MultiResourceSearch/  # Cross-resource queries
│   ├── Operations/           # FHIR operations ($everything, $expand)
│   ├── SearchHelpers/        # Search parameter type definitions
│   ├── SingleResourceSearch/ # Individual FHIR resource search classes
│   └── Write/                # CareTeamWrite, AppointmentWrite
├── Core/                     # FhirService, FanOutSearchHelper, HTTP pipeline, token handling
├── Networking/
│   ├── Core/                 # AriaFhirClient, Builder, Factory patterns
│   └── Helpers/              # Builder extensions, FHIR includes/enums
├── Security/                 # OAuth2 TokenProvider with caching
├── Config/                   # JSON-driven handler dispatch (excluded from build)
├── Resources/                # FHIR resource models (excluded from build)
├── SQL/                      # Direct SQL query infrastructure (excluded from build)
└── Workflows/                # Special Treatment Procedure workflows (excluded from build)

Build

dotnet build AriaAPI.sln

Tests

The AriaAPI.Tests project contains 277 xUnit tests covering the fluent builder, fan-out search, FHIR extensions, search types, name formatting, PHI masking, and configuration validation. No live FHIR server is required.

dotnet test AriaAPI.Tests/AriaAPI.Tests.csproj

NuGet Packaging

dotnet pack AriaAPI/AriaAPI.csproj -o ./out

Produces AriaAPI.1.0.0-beta.1.nupkg. The library targets net10.0.

Configuration

This project uses User Secrets for credential management. Configure FHIR connection settings via the FhirOptions section:

{
  "FhirOptions": {
    "ActiveSystem": "Test",
    "Systems": {
      "Test": {
        "BaseUrl": "https://your-fhir-server/fhir",
        "Auth": {
          "Authority": "https://your-auth-server",
          "ClientId": "your-client-id",
          "ClientSecret": "your-client-secret",
          "Scope": "your-scope"
        }
      }
    }
  }
}

License

See LICENSE.txt.