System Architecture

System Components

┌──────────────────┐     ┌──────────────────┐     ┌──────────────────┐
│  Patient Mobile  │     │   Staff Web GUI   │     │   Patient Web    │
│  (Expo/RN)       │     │   (Next.js 15)    │     │   (Phase 2)      │
└────────┬─────────┘     └────────┬──────────┘     └──────────────────┘
         │                        │
         ▼                        ▼
┌─────────────────────────────────────────────────────────────────────┐
│                          API Services                               │
│  ┌──────────┐ ┌──────────┐ ┌────────┐ ┌───────────┐ ┌───────────┐ │
│  │ fhir-api │ │smart-auth│ │ hr-api │ │inventory  │ │ai-assistant│ │
│  │          │ │          │ │        │ │   -api    │ │           │ │
│  └──────────┘ └──────────┘ └────────┘ └───────────┘ └───────────┘ │
└─────────────────────────────┬───────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────────────┐
│           Managed PostgreSQL — tenant-isolated storage              │
│     Clinical · Identity · Workforce · Inventory · Messaging         │
└─────────────────────────────────────────────────────────────────────┘

API Services

Service	Purpose	Auth
`fhir-api`	All FHIR resource operations (51 resource types)	SMART on FHIR JWT
`smart-auth`	Authentication, token issuance, registration	Public + credentials
`hr-api`	HR workforce management (scheduling, timekeeping)	SMART on FHIR JWT
`inventory-api`	GS1 EPCIS 2.0 inventory management	SMART on FHIR JWT
`ai-assistant`	Clinical AI assistant with tool-calling	SMART on FHIR JWT

Multi-Tenant Architecture

Every data operation is scoped to an organization via org_id from the JWT token:

User Login → Org Selection → JWT with org_id → All queries scoped to org_id

Staff users can belong to multiple organizations with different roles per org
Patient users hold separate organization memberships, tracked independently of staff
National organizations have cross-organization visibility
Terminology (ICD-10, SNOMED CT) is shared across all organizations — a code is not anybody's private data

Isolation is enforced in the data layer rather than in application code, so it cannot be bypassed by a request: there is no parameter that widens, narrows or changes the tenant.

Technology Stack

Layer	Technology
Patient Mobile	React Native + Expo SDK 53
Staff Web	Next.js 15, React 19, Tailwind CSS, shadcn/ui
Backend	Managed PostgreSQL 15 + serverless functions (Deno/TypeScript)
Authentication	SMART on FHIR with ES256 JWT
Real-time	Supabase Realtime (messaging, queue updates)
AI	Anthropic Claude, OpenAI, Google Gemini (configurable)
Internationalization	next-intl (EN, SK, ID)
Charts	Recharts
Scheduling	FullCalendar

All resources follow the HL7 FHIR R4 specification, stored and returned as complete FHIR JSON. What the server supports is not described here by hand — it is published by the server itself as a CapabilityStatement at GET /metadata, and the OpenAPI Explorer is generated from it.

Resource IDs