VigilCare Clinical API

A production-quality clinical backend built with ASP.NET Core 8, PostgreSQL, Apache Kafka, RabbitMQ, Elasticsearch, Redis, and MinIO. The domain models the observe-alert-acknowledge lifecycle at the center of any clinical monitoring system: patient encounters, continuous vital sign and lab result ingest, real-time sepsis and NEWS2 scoring, and clinician notification with automatic escalation.

Implementation status: Twenty-nine planned phases are complete through Phase 31 (plus Phases 20–22) — from schema and CRUD through Kafka, Elasticsearch CQRS, sepsis detection, RabbitMQ paging with DLQ escalation, reconciliation jobs, Prometheus/Grafana observability, the MinIO Parquet data lake, clinical data model expansion, warning alerts and orders, the NEWS2 composite scoring engine, trend detection with alert suppression, qSOFA bedside screening, medication administration with alert correlation annotations, the console replay simulator, the Vue 3 ward dashboard, clinician feedback mode, Glasgow Coma Scale (GCS) scoring, SOFA organ-dysfunction scoring with baseline tracking and delta sepsis alerts, the Sepsis-3 clinical refactor (SIRS removed, qSOFA repositioned as screening, SOFA delta ≥ 2 triggers bundles), frontend GCS entry and SOFA display, expanded simulator scenarios with clinical validation, the Site & Gateway Registry with dual authentication, shared clinical sync contracts, and fleet health Prometheus gauges, the Ward Gateway Service (local-first clinical path with offline buffering and central sync), the FHIR R4 Inbound Facade for EHR integration, Role-Based Access Control (RBAC) with clinical audit logging, the Dashboard Gap Analysis Fixes (SOFA/GCS/qSOFA history charts, patient banner, encounter timeline, medication markers on vital charts), and the Enhanced Dashboard (department overview, sepsis bundle board, critical alert notifications, shift handoff reports, vitals entry form, sortable/filterable ward table). Post-phase hardening includes health check endpoints, Kafka poison pill protection, outbox dead-letter with retry tracking, data lake partial-commit safety, MRN sequence-based generation, FHIR bundle transaction rollback, FHIR R4 read/search endpoints (Patient and Encounter), alert threshold deletion with audit trail, FHIR API key rotation (constant-time multi-key validation), authorization failure logging with Prometheus metrics, JWT signing key validation at startup, and concurrency hardening (transactional sepsis bundle creation, unique active encounter constraint). See Implemented Phases for the full breakdown. Guides: dashboard-guide.md (technical), clinical-testing-guide.md (doctors & nurses).

Domain Model — How It Maps to a Real Clinical System

In a hospital, a patient presents for care and an encounter is opened. Bedside monitors and lab systems post observations continuously against that encounter — either directly via the REST API, through the FHIR R4 facade that maps HL7 FHIR resources from integration engines (Mirth Connect, Rhapsody), or via ward gateway edge nodes that buffer observations locally during connectivity loss and sync to the central API when the link recovers. The FHIR facade also exposes read and search interactions so EHR systems can query patient and encounter data back in standard FHIR R4 format. A rules engine evaluates each observation against configured thresholds and flags abnormal values as clinical alerts. Composite scoring engines (NEWS2, GCS, SOFA, qSOFA) aggregate multiple vitals and labs into acuity scores. The sepsis pathway follows Sepsis-3 consensus: qSOFA ≥ 2 creates a bedside screening alert recommending SOFA labs; when SOFA delta ≥ 2 from baseline confirms organ dysfunction, a SOFA_SEPSIS alert triggers the treatment bundle. Clinicians authenticate via JWT, and role-based access control (RBAC) gates every endpoint by clinical role (Nurse, Physician, Admin, Integration). Clinicians acknowledge and resolve alerts. If a critical alert goes unacknowledged for five minutes, the system escalates to the on-call backup. All clinical write actions — patient registration, alert acknowledgment, threshold changes, encounter transitions — are recorded in an append-only audit log with user identity, IP address, correlation ID, and before/after state. All events flow through Kafka so the Elasticsearch dashboard, scoring engines, and data lake writer consume the same stream independently.

Patient ─────────────────────────── one patient = one MRN, many lifetime encounters
 └── Encounter                       one clinical episode (inpatient, outpatient, ED)
      ├── Observation                 one measurement: vital sign, lab value, SpO₂
      │    └── OutboxEvent            written in the same transaction → relayed to Kafka
      └── ClinicalAlert              generated on threshold breach, qSOFA screen, SOFA delta, or NEWS2 composite score
           ├── OutboxEvent            → Kafka → RabbitMQ → clinician page → escalation
           └── SepsisBundle           auto-created on SOFA_SEPSIS alert → four treatment orders → compliance tracking

Patient

A Patient is registered with demographic information and assigned a Medical Record Number (MRN) — a stable identifier that never changes across encounters. Optional clinical fields include blood type (A+, O-, etc.), known allergies, and emergency contact name/phone. Patient search supports both MRN exact match and name partial match (ILIKE).

Encounter

An Encounter is a single clinical episode. Status follows a controlled machine: scheduled → active → discharged (or cancelled from any pre-discharged state). Optional roomBed and admissionReason fields support ward assignment and clinical context; dischargeDiagnosis is set on discharge. Observations, alerts, and orders belong to an encounter, not directly to a patient — this bounds queries naturally and mirrors real clinical data ownership. Discharge triggers a RabbitMQ job to generate a discharge summary.

AlertThreshold

Alert thresholds define the numeric boundaries that trigger a clinical alert for a given observation code. Each threshold has four optional bounds: criticalLow, warningLow, warningHigh, criticalHigh. Thresholds are pre-loaded into Redis on startup and invalidated on write — they are read on every observation ingest and must not add database latency to the hot path.

Observation

An Observation is a single recorded measurement: a vital sign, lab value, or pulse oximetry reading. Observations are append-only — never updated or deleted. Each observation is evaluated against the Redis-cached threshold immediately on ingest. A CRITICAL breach synchronously creates a ClinicalAlert within the same transaction before the API returns. A WARNING breach is deferred to the Kafka consumer. This split is a deliberate patient safety decision.

An idempotencyKey (partial unique index) prevents duplicate observations when medical devices retry on network failure.

ClinicalAlert

A ClinicalAlert is generated when an observation breaches a threshold, when the qSOFA engine detects two or more organ-dysfunction criteria (screening), when SOFA delta ≥ 2 from baseline confirms sepsis, or when the NEWS2 engine computes a medium/high-risk composite score (or a single-parameter score of 3). Lifecycle: open → acknowledged → resolved (or escalated after a five-minute NACK cycle through the RabbitMQ dead-letter queue). Alerts carry an audit trail: who acknowledged, when, and with what note. Only SOFA_SEPSIS alerts trigger automatic sepsis bundle creation.

SepsisBundle

A SepsisBundle is created automatically when the SOFA scoring engine detects a delta ≥ 2 from baseline (SOFA_SEPSIS alert). Each bundle contains four mandatory treatment elements (blood cultures, serum lactate, broad-spectrum antibiotics, IV fluid resuscitation) mapped to clinical orders that are created simultaneously. A one-hour compliance deadline is set from the recognition time. As linked orders are resulted, bundle elements transition to COMPLETED; when all four are done, the bundle is marked COMPLIANT (within deadline) or NON_COMPLIANT (past deadline). Only one in-progress bundle can exist per encounter at a time.

OutboxEvent

An OutboxEvent is written in the same transaction as any observation or alert, then relayed to Kafka by a background worker. This decouples Kafka availability from the ingest transaction — observations commit to PostgreSQL while Kafka is down, and the relay catches up on recovery.

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Features

• Patient Registration — register patients with MRN generation; optional blood type, allergies, and emergency contact; paginated list with name (ILIKE) and MRN (exact) search; patient detail with active encounter summary
• Encounter Management — open encounters against a patient with optional room/bed and admission reason; encounter status state machine (scheduled → active → discharged / cancelled) with 409 on illegal transitions; unique active encounter per type per patient enforced by partial unique index (concurrent duplicate attempts return 409); optional discharge diagnosis on discharge; encounter timeline as a merged chronological view across status changes, observation summaries, and alerts
• Alert Threshold Management — configure per-observation-code numeric bounds (criticalLow, warningLow, warningHigh, criticalHigh) for 12 observation codes; thresholds pre-loaded into Redis on startup; write-through cache invalidation on update and delete; DELETE /alert-thresholds/{id} removes a threshold with THRESHOLD_DELETED audit trail and Redis cache invalidation
• Observation Ingest — POST /encounters/:id/observations accepts single or small batch (up to 10); idempotency via Idempotency-Key header (partial unique index); plausibility validation per observation code; synchronous critical alert creation within the ingest transaction; warning-range breaches evaluated asynchronously by WarningAlertService (Kafka consumer group warning-evaluator); outbox event written in the same commit; cursor-paginated history on (encounter_id, observation_code, recorded_at DESC)
• Warning Threshold Alerts — WarningEvaluator reads thresholds from Redis; creates WARNING-severity alerts for values above warningHigh or below warningLow that are not also critical breaches; idempotent INSERT WHERE NOT EXISTS per encounter and alert type while status is OPEN or ACKNOWLEDGED; warning alerts are indexed in Elasticsearch but not published to the RabbitMQ paging queue
• Clinical Order Management — POST /encounters/:id/orders create; GET /encounters/:id/orders list with optional status filter; GET /orders/:id detail; PATCH /orders/:id/status status transitions; PATCH /orders/:id/result record result and transition to Resulted; status machine enforces Pending → InProgress → Resulted and terminal Cancelled
• Clinical Alert Lifecycle — paginated alert list per encounter and globally; acknowledge with clinician ID and optional note; resolve (must be acknowledged first); global list filterable by status, severity, and department
• Outbox Relay — IHostedService polling every 500ms; reads unprocessed outbox rows with FOR UPDATE SKIP LOCKED (safe for concurrent instances), publishes to Kafka via idempotent producer (EnableIdempotence = true), marks processed; per-event retry tracking (RetryCount, LastError); events exceeding OutboxMaxRetries (default 10) are marked permanently failed (FailedAt) and excluded from future polls; partitioned by encounterId for per-encounter ordering
• Kafka Pipeline — core topics (observation.recorded, alert.generated, encounter.status.changed, gcs.scored, sepsis bundle topics) with six partitions each; configurable ReplicationFactor (default 3); KRaft mode, no Zookeeper; KAFKA_AUTO_CREATE_TOPICS_ENABLE=false — topics are provisioned explicitly by KafkaTopicProvisioner (including gcs.scored for SOFA CNS re-scoring and sofa.scored for downstream consumers); all consumers protected by PoisonPillGuard (permanent errors skipped, transient errors retried up to MaxPoisonRetries)
• Elasticsearch CQRS Projection — EsIndexerService consumer group upserts patient_encounters documents, appends to the observations index, increments openAlertCount on alert events, stamps news2Score / news2RiskLevel when a NEWS2 alert is generated, and projects sepsisBundleStatus / sepsisBundleElementsCompleted / sepsisBundleDeadlineAt from SOFA-triggered sepsis bundle events; patient/encounter search; per-encounter observation trend (hourly avg/min/max); alert volume summary by department and severity; population query (numeric range aggregation across all patients)
• Sepsis Screening Engine — SepsisEngineService Kafka consumer evaluates qSOFA criteria per encounter using Redis keys with a 30-minute TTL sliding window; qSOFA evaluates respiratory rate ≥ 22, systolic BP ≤ 100, and altered mentation (GCS < 15 or AVPU ≥ 1); on ≥ 2 active criteria and no open screening alert, inserts a QSOFA_SCREEN (WARNING-level) alert idempotently (INSERT WHERE NOT EXISTS); every evaluation is persisted to qsofa_evaluations with criteria values and screen-alert-fired flag; GET /encounters/:id/qsofa/history provides cursor-paginated evaluation history; qSOFA screening recommends ordering SOFA labs — definitive sepsis detection and bundle triggering are handled by SofaScoringService via SOFA delta ≥ 2
• Sepsis Bundle Compliance — SepsisBundleService creates a four-element treatment bundle (blood cultures, serum lactate, broad-spectrum antibiotics, IV fluid resuscitation) when a SOFA_SEPSIS alert fires (delta ≥ 2 from baseline); each element maps to an auto-created clinical order (orderedBy: sepsis-bundle-engine); one-hour compliance deadline from recognition; OrderService.RecordResult calls back to OnOrderResultedAsync to mark elements complete; final element completion sets bundle to COMPLIANT or NON_COMPLIANT; SepsisBundleMonitorService scans every 5 minutes for overdue in-progress bundles past their deadline and marks them NON_COMPLIANT; idempotent — only one in-progress bundle per encounter; GET /encounters/:id/sepsis-bundle/current and GET /sepsis-bundles/:id expose bundle state; Kafka topics sepsis.bundle.created / sepsis.bundle.updated; Prometheus qsofa_detections_total and sepsis_bundle_compliance_total
• NEWS2 Composite Scoring Engine — News2ScoringService Kafka consumer (news2-scoring) evaluates seven vital parameters per encounter (RESP_RATE, SPO2, SYSTOLIC_BP, HEART_RATE, AVPU, TEMP_C, SUPPLEMENTAL_O2) using Redis keys with a 4-hour TTL; when all seven are present, computes the official NEWS2 aggregate score, persists to news2_scores, and creates NEWS2_WARNING (score 5–6 or single param = 3) or NEWS2_EMERGENCY (score ≥ 7) alerts idempotently; consciousness resolves GCS-first with AVPU fallback; GET /encounters/:id/news2/current and /history expose score history; Prometheus news2_scores_total and news2_scoring_duration_seconds
• Glasgow Coma Scale (GCS) Scoring — GcsScoringService Kafka consumer (gcs-scoring) tracks three components (GCS_EYE, GCS_VERBAL, GCS_MOTOR) in Redis; when all three are present, computes total score and classification (MILD / MODERATE / SEVERE), persists to gcs_scores, creates GCS_CRITICAL (total ≤ 8) or GCS_WARNING (9–12) alerts idempotently, and publishes gcs.scored via outbox for downstream SOFA CNS re-scoring; feeds NEWS2 consciousness and qSOFA altered mentation; GET /encounters/:id/gcs exposes the latest score; GET /encounters/:id/gcs/history provides cursor-paginated score history with component breakdown; Prometheus gcs_scores_total
• SOFA Organ-Dysfunction Scoring — SofaScoringService Kafka consumer (sofa-scoring) subscribes to observation.recorded and gcs.scored; scores six organ systems (respiratory, coagulation, liver, cardiovascular, CNS, renal) from Redis lab cache with carry-forward staleness, MAP derivation, SpO₂/FiO₂ fallback, and vasopressor detection from MedicationAdministration; persists to sofa_scores with baseline tracking (≥ 4 populated organ systems) and delta-from-baseline; delta ≥ 2 creates SOFA_SEPSIS (CRITICAL), delta = 1 creates SOFA_WARNING; skips stale Kafka events when the encounter row no longer exists; GET /encounters/:id/sofa and /sofa/history expose scores; Prometheus sofa_scores_total and sofa_scoring_duration_seconds
• Trend Detection Engine — TrendAnalyzerService Kafka consumer (trend-analyzer) tracks rate-of-change for five vital parameters (HEART_RATE, RESP_RATE, SYSTOLIC_BP, TEMP_C, SPO2) using Redis sliding-window history; when velocity exceeds configured thresholds (e.g. 72→95 bpm in 30 min), creates a RAPID_DETERIORATION alert even if the current value is below warning thresholds; Prometheus trend_alerts_total and trend_analysis_duration_seconds
• Alert Suppression Windows — acknowledging a suppressible alert (WARNING_*, NEWS2_WARNING) sets a Redis key suppress:{encounterId}:{alertType} with a configurable TTL (default 30 min from AlertSuppression config; optional per-code override via alert_thresholds.suppression_window_minutes); WarningEvaluator and News2Detector check suppression before creating new warning alerts; critical alerts (CRITICAL_*, NEWS2_EMERGENCY, SEPSIS_WARNING, RAPID_DETERIORATION) are never suppressed; observations and NEWS2 scores continue to persist during suppression; Prometheus alert_suppressions_total
• Medication Administration — POST /encounters/:id/medications records drug administrations (name, dose, route, timestamp, administered-by); GET /encounters/:id/medications lists with optional since filter; GET /medications/:id detail; active-encounter guard; FluentValidation on request DTOs
• Medication Correlation Annotations — MedicationCorrelationHelper appends medication context to warning and NEWS2 alert details when a mapped drug was administered within the correlation window (default 90 min); drug-to-vital mappings in MedicationCorrelation config (appsettings.json); annotates rather than suppresses — alerts still fire; sepsis, trend, and critical sync-path alerts are never annotated; design rationale in docs/decisions/medication-correlation-design.md
• Ward Dashboard APIs — GET /encounters returns paginated WardEncounterSummary rows (patient name/MRN, room/bed, department, status, latest NEWS2 score, live qSOFA criteria count from Redis, sepsis bundle status, open alert count, SOFA score/delta, GCS score/classification, attending physician, admitted-at, last observation time); filterable by status and department; GET /encounters/:id/qsofa/current exposes Redis-backed qSOFA state; GET /sepsis-bundles lists bundles hospital-wide with optional status filter (returns SepsisBundleSummary with patient demographics, elements, and deadlines); CORS policy Dashboard allows configured origins (default http://localhost:5173)
• Ward Dashboard Frontend — Vue 3 SPA (vigilcare-dashboard/) with virtual ward table (multi-column sortable, patient search, quick-filters for critical/alerts/sepsis), patient detail (vitals, scores, alerts, orders, sepsis bundle, GCS entry form, SOFA score panel, patient banner with demographics/allergies/emergency contact, encounter timeline, vitals entry form for manual observation recording), alert center (global acknowledge/resolve with role-aware modal and acknowledgment note preview), department overview (unit-level snapshot cards with acuity bars, patient/alert/bundle counts per department), sepsis bundle board (real-time countdown timers, on-track/at-risk/overdue urgency sorting), critical alert banner with browser notifications and audible tone, shift handoff report generator (SBAR format with ward summary, exportable via print/PDF), vital sign trend charts with medication administration markers and local replay scrubbing, NEWS2 history chart, SOFA history chart with organ-system breakdown, GCS history chart with component tracking, qSOFA evaluation history, alert reasoning with optional medication context, and clinician feedback on every alert; polls API every 5–10 s; guides in docs/dashboard-guide.md and docs/clinical-testing-guide.md
• FHIR R4 Inbound Facade — POST /fhir/R4/{Patient,Encounter,Observation,MedicationAdministration} accepts FHIR R4 JSON resources (application/fhir+json); POST /fhir/R4 processes transaction Bundles (Patient → Encounter → Observation in dependency order); GET /fhir/R4/metadata returns a CapabilityStatement; LOINC-to-internal code mapping (19 observation codes + SNOMED CT fallbacks); Fahrenheit-to-Celsius unit conversion; ExternalResourceIdentifier table links hospital MRNs and visit numbers to internal UUIDs for idempotent upserts; FhirApiKeyOrJwtMiddleware authenticates via JWT bearer or X-Api-Key header (supports multiple keys via Fhir:ApiKeys array for zero-downtime rotation; constant-time comparison via CryptographicOperations.FixedTimeEquals); FhirExceptionFilter returns FHIR OperationOutcome on errors; configurable identifier systems, department codes, and encounter class mappings via Fhir config section; Prometheus fhir_ingest_total and fhir_mapping_errors_total; integration guide for Mirth Connect HL7v2→FHIR channels in docs/integration/mirth-fhir-channels.md
• FHIR R4 Read/Search — GET /fhir/R4/Patient/{id} reads a Patient by internal ID; GET /fhir/R4/Patient searches by identifier (system|value) or lists all patients; GET /fhir/R4/Encounter/{id} reads an Encounter by internal ID; GET /fhir/R4/Encounter searches by patient (UUID) and/or status (in-progress, finished, cancelled); all return FHIR R4 JSON (application/fhir+json); search endpoints return Bundle.type=searchset; requires fhir:read permission (Admin and Integration roles); internal resources mapped back to FHIR via PatientFhirMapper.ToFhirResponse / EncounterFhirMapper.ToFhirResponse with hospital identifier resolution; Prometheus fhir_read_total counter with resource_type, interaction, outcome labels
• Role-Based Access Control (RBAC) — JWT bearer authentication (POST /auth/login); four clinical roles (Nurse, Physician, Admin, Integration) with 17 granular permissions (patients:read, alerts:acknowledge, thresholds:write, fhir:ingest, fhir:read, audit:read, etc.); AuthorizePermission attribute on every controller action; PermissionAuthorizationHandler resolves role → permission at runtime from ClinicalRolePermissionMap and logs authorization failures with structured details (user, role, permission, endpoint) plus authorization_failures_total Prometheus counter; CurrentUserService exposes authenticated identity (user ID, display name, role, IP address) to services; nurses and physicians get clinical read/write permissions; admins additionally get thresholds:write, fhir:read, audit:read, and users:admin; integration accounts get FHIR ingest and read access; FHIR endpoints accept both JWT and X-Api-Key authentication via FhirApiKeyOrJwtMiddleware; alert acknowledgedBy is set from the authenticated user identity, not the request body; startup validates JWT signing key is at least 256 bits (HMAC-SHA256 minimum); four seeded demo users (nurse.demo, physician.demo, admin.demo, integration.mirth); frontend login page with localStorage token persistence and automatic Authorization: Bearer header injection
• Clinical Audit Logging — append-only clinical_audit_logs table records clinical write actions with user identity, entity type/ID, before/after state (JSONB), reason, IP address, and correlation ID; ten audit actions (THRESHOLD_CREATED, THRESHOLD_UPDATED, THRESHOLD_DELETED, ALERT_ACKNOWLEDGED, ALERT_RESOLVED, ENCOUNTER_STATUS_CHANGED, PATIENT_REGISTERED, SUPPRESSION_WINDOW_SET, USER_LOGIN, AUTHORIZATION_DENIED); AuditService writes log entries inline with domain operations; GET /audit-logs admin-only query endpoint with filters by entity type, entity ID, user ID, action, and time range; indexed on entity type, entity ID, user ID, and timestamp
• Site & Gateway Registry — ClinicalSite and WardGateway domain entities model ward edge nodes that buffer clinical data during connectivity loss; POST /sites creates clinical sites; POST /sites/{siteId}/gateways registers gateways under a site; PATCH /gateways/{gatewayId}/heartbeat (gateway API key auth) updates status (ONLINE, DEGRADED, OFFLINE) and reported buffer depth; GET /sites/{siteId}/gateways lists gateways with optional ?department= filter; dual authentication — JWT + RBAC (users:admin) for admin CRUD, GatewayApiKeyAuthenticationHandler (X-Api-Key + X-Gateway-Id) for gateway heartbeat and future sync upload; constant-time key comparison via CryptographicOperations.FixedTimeEquals; VigilCare.ClinicalContracts shared class library with sync DTOs (ClinicalSyncBatchRequest, SyncedObservation, SyncedAlertEvent, GatewayHeartbeatRequest) consumed by both central API and ward gateway projects; Prometheus ward_gateways_offline_gauge and ward_gateway_buffer_depth via WardGatewayMetricsCollector (60s periodic); GatewayRegistrySeeder provides demo site and gateway for Docker Compose and tests; FluentValidation on all request DTOs; GatewayRegistryTests and ClinicalContractsTests integration tests
• Ward Gateway Service — VigilCare.WardGateway (http://localhost:5081) is a standalone ASP.NET Core 8 deployable with its own PostgreSQL, Redis, and RabbitMQ; ingests observations locally via POST /encounters/:id/observations with plausibility validation, Redis-cached threshold evaluation, and synchronous critical alert creation; LocalWarningEvaluator creates warning-range alerts; BufferedSyncWriter writes all clinical events to buffered_sync_items for central upload; EncounterReplicaSyncService pulls patient/encounter data from central API; ThresholdCacheLoader fetches thresholds from central into local Redis; CentralReachabilityService tracks central API connectivity; GatewayHeartbeatService reports status and buffer depth; SyncUploaderService batches and uploads buffered items when online; local RabbitMQ paging and escalation queues; GET /encounters ward list and GET /encounters/:id detail; GET /health/live and GET /health/ready (Redis, RabbitMQ, encounter replica readiness); Docker Compose ward-gateway profile
• Health Check Endpoints — GET /health/live (liveness — always returns 200 if the process is running) and GET /health/ready (readiness — checks PostgreSQL, Redis, Kafka, RabbitMQ, and Elasticsearch connectivity); both return structured JSON with per-check status and duration; anonymous access; suitable for Kubernetes probes and load balancer health checks
• Kafka Poison Pill Protection — PoisonPillGuard prevents a single un-processable message from blocking a consumer partition forever; permanent errors (malformed JSON, bad format) are skipped immediately; transient errors are retried up to MaxPoisonRetries (default 5) before the offset is committed and the message is abandoned; all eight Kafka consumers use the guard; skipped messages are logged at CRITICAL with full payload and tracked by Prometheus kafka_poison_pills_skipped_total (labeled by consumer group and topic)
• Outbox Dead-Letter with Retry Tracking — OutboxRelayService tracks RetryCount, LastError, and FailedAt per event; events that fail OutboxMaxRetries (default 10) Kafka produce attempts are marked permanently failed (FailedAt set) and excluded from future relay polls; uses FOR UPDATE SKIP LOCKED for safe concurrent relay instances; idempotent Kafka producer (EnableIdempotence = true) prevents duplicate messages from network-level retries
• Data Lake Partial-Commit Safety — DataLakeWriterService commits Kafka offsets only for topic-partitions where all MinIO uploads succeeded; failed partition buffers are retained in memory and retried on the next flush cycle; prevents data loss from partial upload failures
• ThresholdCacheLoader Resilience — retries Redis connection up to 3 times with exponential backoff (2s, 4s, 8s); if Redis remains unavailable, the application starts without the cache and observation ingest falls back to PostgreSQL queries for threshold lookups
• MRN Sequence Generation — MRN numbers are generated via a PostgreSQL sequence (mrn_seq) instead of MAX+1 queries; eliminates race conditions under concurrent patient registration; configurable prefix and digit count via PatientOptions
• FHIR Bundle Transaction Rollback — FhirBundleProcessor wraps all bundle entry processing in a database transaction; on any entry failure, the transaction is rolled back and the response includes the OperationOutcome for the failed entry; prevents partial state from orphaned Patient/Encounter records
• Clinician Feedback Mode — six quick ratings per alert (useful, too early, too late, false positive, missing context, would act); optional notes; Feedback Summary with aggregate stats and JSON/CSV export; client-side persistence for product research
• Console Replay Simulator — standalone VigilCare.Simulator .NET console app replays JSON scenario files against the live API with configurable speed (--speed 0 instant, 60 = 60× faster); commands: replay, replay-all, validate, dry-run; optional --poll shows alerts, NEWS2, GCS, SOFA, and sepsis bundle state during replay; --gateway targets the ward gateway (http://localhost:5081) with --encounter-id, --skip-setup, and --gateway-token; alert_ack events poll for open alerts on central before acknowledging (handles async alert pipeline at --speed 0); twelve sample scenarios in VigilCare.Simulator/Scenarios/List/ (including ward outage reconnect, GCS neurological decline, SOFA sepsis progression, and SpO₂/FiO₂ fallback); user guide in docs/simulator-guide.md
• RabbitMQ Notification Workers — NotificationPublisherService reads alert.generated from Kafka and publishes paging jobs to alerts.paging.queue; PagingWorkerService sends the page and waits for acknowledgment; if no ack arrives before timeout it NACKs to alerts.paging.dlq with x-message-ttl = 300000ms; if the host is stopping, in-flight paging messages are NACKed with requeue=true so they are retried after restart and do not false-escalate; EscalationWorkerService pages the on-call backup and sets alert status to escalated; DischargeSummaryWorkerService reads encounter.status.changed, generates a discharge summary, and stores it in MinIO under /discharge-summaries/{encounterId}/summary.pdf
• Data Lake Writer — DataLakeWriterService (consumer group data-lake-writer) buffers observation.recorded, alert.generated, and encounter.status.changed events, flushes date-partitioned Parquet files to MinIO (/observations/, /alerts/, /encounters/), and commits Kafka offsets only for topic-partitions where all uploads succeeded; failed partition buffers are retained in memory and retried on the next flush cycle (prevents data loss from partial upload failures); shutdown flush uses an uncanceled token so MinIO writes complete on Ctrl+C; kafka_partition and kafka_offset columns provide audit lineage
• Reconciliation Jobs — three scheduled checks: (1) unacknowledged CRITICAL alerts older than 30 minutes, (2) pending orders without results after 4 hours, (3) active inpatients with no observation in 2 hours; each finding creates a reconciliation_alerts row and publishes to RabbitMQ
• Standard Envelope — all responses use a consistent { success, statusCode, data, error } wrapper; validation errors use the same shape; ApiBehaviorOptions overridden so model validation also produces the standard envelope with field-level details
• Input Validation — FluentValidation validators on all request DTOs (patient registration, encounter open, observation ingest, alert acknowledge, alert thresholds, orders); invalid requests return 400 before reaching the service layer
• Observability — Serilog structured logging enriched with correlationId, encounterId, patientId on alert paths; Seq sink (http://localhost:5345); Prometheus (http://localhost:9101) scrapes GET /metrics; application metric families via ClinicalMetrics (including GCS and SOFA scoring) and three background collectors (AlertsUnacknowledgedCollector, OutboxPendingCollector, KafkaConsumerLagCollector); Grafana clinical dashboard (http://localhost:3101, admin/admin) with alerts_unacknowledged_gauge as the primary safety panel; per-request correlation IDs in request logs and X-Correlation-Id response headers
• Swagger UI — OpenAPI spec via Swashbuckle (Development only)

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Architecture

HTTP request
  → FhirApiKeyOrJwtMiddleware (X-Api-Key or JWT bearer for /fhir/* routes)
  → CorrelationIdMiddleware
  → ExceptionHandlerMiddleware
  → JWT Authentication + RBAC (PermissionAuthorizationHandler) / GatewayApiKeyAuthenticationHandler (X-Api-Key for gateway routes)
  → Controllers (REST API + FHIR R4 ingest + Site/Gateway registry)
  → Services
      ├── CurrentUserService (authenticated user identity from JWT claims)
      ├── AuditService (append-only clinical_audit_logs on write actions)
      ├── PostgreSQL (EF Core — writes, keyed reads)
      ├── Redis (threshold cache, qSOFA state, NEWS2 parameter state, GCS state, SOFA lab cache, trend history, alert suppression keys)
      └── OutboxEvent (same transaction as domain write)

IHostedServices (background):
  ThresholdCacheLoader   → pre-loads Redis on startup
  KafkaTopicProvisioner  → creates topics with correct partition count
  RabbitMqTopologyProvisioner → declares exchange, queues, DLQ bindings
  ElasticIndexProvisioner → creates index mappings
  OutboxRelayService     → PostgreSQL outbox → Kafka (every 500ms)
  EsIndexerService       → Kafka → Elasticsearch (consumer group: es-indexer)
  SepsisEngineService    → Kafka → Redis qSOFA state → PostgreSQL QSOFA_SCREEN alert (consumer group: sepsis-engine)
  WarningAlertService    → Kafka → WarningEvaluator (+ MedicationCorrelationHelper) → PostgreSQL WARNING alert (consumer group: warning-evaluator)
  News2ScoringService    → Kafka → News2Detector (+ MedicationCorrelationHelper) → Redis NEWS2 state → PostgreSQL score + alert (consumer group: news2-scoring)
  GcsScoringService      → Kafka → GcsDetector → Redis GCS components → PostgreSQL gcs_scores + gcs.scored outbox (consumer group: gcs-scoring)
  SofaScoringService     → Kafka (observation.recorded + gcs.scored) → SofaDetector → Redis SOFA lab cache → PostgreSQL sofa_scores + delta alerts → SepsisAlertHandler → SepsisBundleService on SOFA_SEPSIS (consumer group: sofa-scoring)
  TrendAnalyzerService   → Kafka → TrendDetector → Redis trend history → PostgreSQL RAPID_DETERIORATION alert (consumer group: trend-analyzer)
  AlertSuppressionService → Redis suppress:{enc}:{type} keys set on acknowledge; read by WarningEvaluator, News2Detector, QsofaDetector
  NotificationPublisherService → Kafka → RabbitMQ paging.queue (consumer group: notification-publisher)
  PagingWorkerService    → RabbitMQ paging.queue → log page → NACK on timeout (or requeue on shutdown)
  EscalationWorkerService → RabbitMQ escalation.queue → update alert status
  DischargeSummaryWorkerService → RabbitMQ discharge.queue → MinIO PDF
  DataLakeWriterService  → Kafka (data-lake-writer) → Parquet files in MinIO
  ReconciliationScheduler → three scheduled safety checks → reconciliation_alerts + RabbitMQ
  SepsisBundleMonitorService → polls overdue bundles every 5 min → marks NON_COMPLIANT
  PoisonPillGuard (per consumer) → skips permanently malformed messages after MaxPoisonRetries
  AlertsUnacknowledgedCollector → polls PostgreSQL every 30s → alerts_unacknowledged_gauge
  OutboxPendingCollector     → polls outbox every 30s → outbox_pending_events
  KafkaConsumerLagCollector  → polls four consumer groups every 30s → kafka_consumer_lag
  WardGatewayMetricsCollector → polls gateway status/buffer depth every 60s → ward_gateways_offline_gauge, ward_gateway_buffer_depth
  ClinicalMetrics (singleton) → inline counters/histogram from ingest, qSOFA, NEWS2, GCS, SOFA, trend, suppression, bundle compliance, escalation paths

Ward Gateway (VigilCare.WardGateway — separate deployable on port 5081):
  HTTP request → ExceptionHandlerMiddleware → Controllers (Observations, Alerts, Encounters, CentralRequired)
  Services:
    LocalObservationService → PostgreSQL (ward) + Redis (ward) threshold cache → critical alert + outbox
    LocalWarningEvaluator   → Redis threshold lookup → WARNING alert creation
    LocalAlertService       → Acknowledge/resolve local alerts
    BufferedSyncWriter      → Writes sync items to buffered_sync_items table
    EncounterReadService    → Ward encounter list and detail views
  BackgroundServices:
    EncounterReplicaSyncService → pulls patient/encounter data from central API
    ThresholdCacheLoader        → fetches thresholds from central → local Redis
    CentralReachabilityService  → polls central /health/ready every 30s
    GatewayHeartbeatService     → reports status + buffer depth to central registry
    SyncUploaderService         → batches buffered_sync_items → central API upload
    LocalPagingWorkerService    → local RabbitMQ paging queue → clinician page
    LocalEscalationWorkerService → local RabbitMQ escalation queue → on-call backup

Why Kafka and RabbitMQ coexist: Kafka is an append-only log — the same observation event reaches the Elasticsearch indexer, the sepsis engine, and the data lake independently without coordination. Each consumer holds its own offset and can replay from the beginning. RabbitMQ handles the action side: one message, one worker, one page. A duplicate page at 3am is a patient safety concern, not a minor inconvenience — RabbitMQ's acknowledgment-then-delete model is correct here. The DLQ TTL-based escalation has no equivalent in Kafka.

---

Tech Stack

Layer	Technology
Server	ASP.NET Core 8 (.NET 8.0)
Database	PostgreSQL 16 with EF Core 8 (code-first migrations)
Cache / scoring state	Redis 7
Message log	Apache Kafka 3.7 (KRaft, 6 partitions per topic)
Task queue	RabbitMQ 3.13 (direct exchange, DLQ escalation)
Search / analytics	Elasticsearch 8.13 (CQRS read projection)
Data lake	MinIO (Parquet, S3-compatible)
Logging	Serilog + Seq sink
Metrics	prometheus-net.AspNetCore (GET /metrics)
Dashboards	Prometheus 2.52 + Grafana 10.4
Data lake format	Parquet.Net 4.x
Authentication	JWT Bearer (Microsoft.AspNetCore.Authentication.JwtBearer)
Password hashing	BCrypt.Net-Next
FHIR	Hl7.Fhir.R4 (Firely SDK — parsing, serialization, model)
Docs	Swagger / OpenAPI (Swashbuckle)
Validation	FluentValidation.AspNetCore
Testing	xUnit + Testcontainers + WebApplicationFactory
Ward dashboard	Vue 3 + Vite + Pinia + Tailwind CSS v4 + Chart.js (vigilcare-dashboard/)

---

Project Structure

VigilCareClinicalAPI/
├── Program.cs                                  # Service registration, middleware, seed on startup
├── appsettings.json                            # Connection strings, Kafka, Elasticsearch, RabbitMQ, MinIO, Serilog, ReconciliationJobs
├── Controllers/
│   ├── AuthController.cs                       # JWT login + authenticated user profile (GET /auth/me)
│   ├── AuditLogsController.cs                  # Clinical audit log query (Admin only)
│   ├── PatientsController.cs                   # Patient CRUD, search by name/MRN
│   ├── EncountersController.cs                 # Encounter list (ward summary), get, status PATCH, timeline
│   ├── MedicationsController.cs                # Medication administration create, list, get
│   ├── QsofaController.cs                      # Current qSOFA criteria count (Redis-backed) + cursor-paginated evaluation history
│   ├── ObservationsController.cs               # Ingest POST, cursor-paginated GET
│   ├── AlertThresholdsController.cs            # Threshold CRUD + cache invalidation
│   ├── AlertsController.cs                     # Alert list (global + per-encounter), acknowledge, resolve
│   ├── OrdersController.cs                     # Order create, list, get, status transition, record result
│   ├── News2Controller.cs                      # Current NEWS2 score and cursor-paginated history
│   ├── GcsController.cs                        # Latest GCS score and cursor-paginated history per encounter
│   ├── SofaController.cs                       # Current SOFA score and cursor-paginated history
│   ├── SepsisBundlesController.cs              # Current bundle per encounter, bundle detail by ID
│   ├── SitesController.cs                      # Clinical site CRUD (create, list, get)
│   ├── GatewaysController.cs                   # Gateway register, list, get, heartbeat (dual auth: JWT + API key)
│   ├── FhirIngestController.cs                 # FHIR R4 ingest: Patient, Encounter, Observation, MedicationAdministration, Bundle
│   ├── FhirReadController.cs                   # FHIR R4 read/search: GET Patient/{id}, GET Patient, GET Encounter/{id}, GET Encounter
│   ├── FhirMetadataController.cs               # FHIR R4 CapabilityStatement (GET /fhir/R4/metadata)
│   └── AnalyticsController.cs                  # Elasticsearch-backed patient search, trend, alert summary, population
├── Domains/
│   ├── Entities/
│   │   ├── Patient.cs
│   │   ├── Encounter.cs                        # Status machine; SetStatus() enforces transition matrix
│   │   ├── AlertThreshold.cs
│   │   ├── Observation.cs                      # Append-only; IdempotencyKey; partial unique index
│   │   ├── ClinicalAlert.cs                    # open → acknowledged → resolved / escalated
│   │   ├── Order.cs
│   │   ├── News2Score.cs                       # Composite score with seven component scores + risk level
│   │   ├── GcsScore.cs                         # Eye/verbal/motor components, total, classification
│   │   ├── SofaScore.cs                        # Six organ-system scores, baseline flag, delta, staleness JSON
│   │   ├── QsofaEvaluation.cs                  # Per-evaluation qSOFA record: criteria count, values, screen alert fired
│   │   ├── OutboxEvent.cs                      # topic + payload JSONB + processed_at
│   │   ├── ReconciliationAlert.cs
│   │   ├── SepsisBundle.cs                     # Four-element treatment bundle with 1-hour compliance deadline
│   │   ├── SepsisBundleElement.cs              # Individual bundle element linked to a clinical order
│   │   ├── MedicationAdministration.cs         # Drug administration record per encounter
│   │   ├── ExternalResourceIdentifier.cs       # Links external system identifiers (MRN, visit#) to internal UUIDs
│   │   ├── ClinicalSite.cs                     # Hospital site with site code, name, address
│   │   ├── WardGateway.cs                      # Ward edge node with status, buffer depth, heartbeat, sync timestamps
│   │   ├── ClinicalUser.cs                     # Username, BCrypt password hash, display name, role, active flag
│   │   └── ClinicalAuditLog.cs                 # Append-only audit trail: action, entity, user, before/after JSONB, IP, correlation ID
│   └── Enums/
│       ├── EncounterStatus.cs                  # Scheduled, Active, Discharged, Cancelled
│       ├── ClinicalRole.cs                     # Nurse, Physician, Admin, Integration
│       ├── AuditAction.cs                      # ThresholdCreated/Updated/Deleted, AlertAcknowledged/Resolved, EncounterStatusChanged, PatientRegistered, SuppressionWindowSet, UserLogin, AuthorizationDenied
│       ├── EncounterType.cs                    # Inpatient, Outpatient, Emergency
│       ├── AlertSeverity.cs                    # Warning, Critical
│       ├── AlertStatus.cs                      # Open, Acknowledged, Resolved, Escalated
│       ├── AlertType.cs                        # Threshold breach, QSOFA_SCREEN, SOFA_SEPSIS, warning*, NEWS2_*, GCS_*, …
│       ├── GatewayStatus.cs                    # Online, Degraded, Offline with ToDbString/FromDbString
│       ├── BloodType.cs                        # A+, O-, AB-, … with ToDbString/FromDbString
│       ├── ObservationSource.cs                # Device, Manual, Lab
│       ├── SepsisBundleComplianceStatus.cs     # InProgress, Compliant, NonCompliant
│       ├── SepsisBundleElementStatus.cs        # Pending, Completed
│       ├── SepsisBundleElementType.cs          # BloodCultures, SerumLactate, BroadSpectrumAntibiotics, IvFluidResuscitation
│       ├── ExternalResourceType.cs              # Patient, Encounter — for external identifier linking
│       └── OrderType.cs / ReconciliationCheckType.cs / Department.cs / OrderStatus.cs
│   └── Json/
│       ├── ObservationSourceJsonConverter.cs
│       ├── DepartmentJsonConverter.cs
│       └── BloodTypeJsonConverter.cs           # Clinical notation (A+, AB-) in JSON API
├── Fhir/
│   ├── Codes/
│   │   ├── LoincCodeMapper.cs                  # LOINC → internal observation code (19 codes + SNOMED CT fallbacks)
│   │   ├── LoincMapping.cs                     # Code mapping record (InternalCode, ExpectedUnit, AllowFahrenheit)
│   │   └── FhirUnitConverter.cs                # Fahrenheit→Celsius conversion for temperature observations
│   ├── Mapping/
│   │   ├── PatientFhirMapper.cs                # FHIR Patient ↔ internal Patient upsert
│   │   ├── EncounterFhirMapper.cs              # FHIR Encounter ↔ internal Encounter upsert (ACT class, department, status)
│   │   ├── ObservationFhirMapper.cs            # FHIR Observation → IngestObservationRequest (single + component)
│   │   ├── MedicationAdministrationFhirMapper.cs # FHIR MedicationAdministration → CreateMedicationAdministrationRequest
│   │   ├── FhirReferenceResolver.cs            # Resolves FHIR references (identifier or UUID) to internal IDs
│   │   └── FhirMappingHelpers.cs               # DateTimeOffset extraction, reference parsing utilities
│   ├── FhirBundleProcessor.cs                  # Transaction Bundle processing in dependency order (Patient→Encounter→Obs)
│   ├── FhirExceptionFilter.cs                  # Converts exceptions to FHIR OperationOutcome responses
│   ├── FhirMappingException.cs                 # Typed exception for FHIR mapping failures
│   └── FhirOperationOutcomeBuilder.cs          # Builds FHIR OperationOutcome from exceptions and error codes
├── Authorization/
│   ├── AuthorizePermissionAttribute.cs         # [AuthorizePermission("patients:read")] attribute
│   ├── ClinicalPermissions.cs                  # 17 permission constants (patients:read, thresholds:write, fhir:read, audit:read, …)
│   ├── ClinicalRolePermissionMap.cs            # Role → permission set (Nurse, Physician, Admin, Integration)
│   ├── PermissionAuthorizationHandler.cs       # ASP.NET Core authorization handler resolving role claims
│   ├── PermissionPolicyProvider.cs             # Dynamic policy provider for perm:* policies
│   └── PermissionRequirement.cs                # IAuthorizationRequirement for a single permission string
├── Authentication/
│   └── GatewayApiKeyAuthenticationHandler.cs   # X-Api-Key + X-Gateway-Id auth for gateway heartbeat/sync routes
├── Services/
│   ├── Interfaces/                             # IPatientService, IEncounterService, IAuditService, IAuthService, ICurrentUserService, ISiteService, IGatewayRegistryService, …
│   ├── AuthService.cs                          # Login (BCrypt verify), JWT generation, login audit log
│   ├── AuditService.cs                         # Append-only clinical audit log writer (user, entity, before/after, IP, correlation ID)
│   ├── CurrentUserService.cs                   # Extracts authenticated user identity from JWT claims (HttpContext)
│   ├── PatientService.cs
│   ├── EncounterService.cs                     # Status state machine + ConflictException on invalid transitions
│   ├── AlertThresholdService.cs                # CRUD + Redis write-through invalidation
│   ├── ObservationService.cs                   # Ingest transaction: idempotency → plausibility → threshold → alert → outbox; emits Prometheus counters
│   ├── ObservationQueryService.cs              # Cursor-paginated history
│   ├── AlertService.cs                         # Acknowledge (sets suppression), resolve, list
│   ├── AlertSuppressionService.cs              # Redis suppress:{enc}:{type} TTL keys
│   ├── OrderService.cs                         # Order lifecycle; status machine; calls SepsisBundleService.OnOrderResultedAsync on result
│   ├── News2Service.cs                         # Current score + cursor-paginated history from PostgreSQL
│   ├── GcsService.cs                           # Latest GCS score from PostgreSQL
│   ├── SofaService.cs                          # Current, baseline, and history SOFA scores
│   ├── SepsisBundleService.cs                  # Bundle creation, element completion, compliance evaluation
│   ├── MedicationService.cs                    # Medication CRUD; GetRecentForEncounterAsync for correlation
│   ├── QsofaService.cs                         # Redis-backed qSOFA criteria count for API/dashboard
│   ├── ExternalIdentifierService.cs            # Links/resolves external system identifiers to internal UUIDs
│   ├── SiteService.cs                          # Clinical site CRUD
│   ├── GatewayRegistryService.cs               # Gateway register, list, heartbeat, mark offline
│   ├── WarningEvaluator.cs                     # Warning-range evaluation; suppression + medication annotation; idempotent INSERT
│   ├── AnalyticsService.cs                     # Elasticsearch query wrappers
│   └── PlausibilityValidator.cs                # Per-code numeric range guard
├── Trend/
│   ├── TrendCalculator.cs                      # Pure static rate-of-change logic
│   └── TrendDetector.cs                        # Redis history + RAPID_DETERIORATION alert creation
├── Medication/
│   └── MedicationCorrelationHelper.cs          # Appends drug context to warning/NEWS2 alert details
├── Validators/                                 # FluentValidation — RegisterPatient, OpenEncounter, IngestObservation, CreateMedicationAdministration, CreateSiteRequest, RegisterGatewayRequest, GatewayHeartbeatRequest, …
├── Observability/
│   └── Metrics/
│       └── ClinicalMetrics.cs                  # Prometheus metric families (counters, histograms, gauges); includes FHIR read and authorization failure metrics
├── BackgroundServices/
│   ├── ThresholdCacheLoader.cs                 # Pre-loads all thresholds into Redis on startup
│   ├── KafkaTopicProvisioner.cs                # Creates topics with NumPartitions from config
│   ├── OutboxRelayService.cs                   # Polls outbox every 500ms; publishes to Kafka; marks processed
│   ├── Metrics/
│   │   ├── AlertsUnacknowledgedCollector.cs    # Polls open CRITICAL alerts > 5 min → alerts_unacknowledged_gauge
│   │   ├── OutboxPendingCollector.cs           # Polls unprocessed outbox rows → outbox_pending_events
│   │   ├── KafkaConsumerLagCollector.cs        # Lag for es-indexer, sepsis-engine, notification-publisher, data-lake-writer
│   │   └── WardGatewayMetricsCollector.cs      # Polls gateway status/buffer depth every 60s → offline gauge, buffer depth
│   ├── ElasticsSearch/
│   │   ├── ElasticIndexProvisioner.cs          # Creates patient_encounters, observations, clinical_alerts indices
│   │   └── EsIndexerService.cs                 # consumer group: es-indexer; upserts Elasticsearch documents
│   ├── SepsisEngineService.cs                  # consumer group: sepsis-engine; qSOFA screening via Redis TTL keys
│   ├── WarningAlertService.cs                  # consumer group: warning-evaluator; observation.recorded → WARNING alerts
│   ├── News2ScoringService.cs                  # consumer group: news2-scoring; observation.recorded → NEWS2 score + alert
│   ├── GcsScoringService.cs                    # consumer group: gcs-scoring; observation.recorded → GCS score + alert
│   ├── SofaScoringService.cs                   # consumer group: sofa-scoring; observation.recorded + gcs.scored → SOFA score + delta alerts
│   ├── TrendAnalyzerService.cs                 # consumer group: trend-analyzer; observation.recorded → RAPID_DETERIORATION alert
│   ├── SepsisBundleMonitorService.cs           # Polls every 5 min; marks overdue in-progress bundles NON_COMPLIANT
│   ├── Notifications/
│   │   ├── NotificationPublisherService.cs     # consumer group: notification-publisher; alert.generated → RabbitMQ paging.queue
│   │   ├── PagingWorkerService.cs              # RabbitMQ consumer; logs page; NACK on ack timeout → DLQ, requeue on graceful shutdown
│   │   ├── EscalationWorkerService.cs          # RabbitMQ escalation.queue; logs escalation; sets alert.status = escalated
│   │   └── DischargeSummaryWorkerService.cs    # RabbitMQ discharge.queue; generates summary PDF; uploads to MinIO
│   └── Reconciliation/
│       ├── ReconciliationScheduler.cs          # Runs three safety checks on a configurable interval
│       ├── UnacknowledgedAlertsCheck.cs        # CRITICAL alerts unacknowledged > 30 min
│       ├── PendingOrdersCheck.cs               # Pending orders without results > 4 hours
│       ├── DisconnectedMonitorsCheck.cs      # Active inpatients with no observation > 2 hours
│       └── ReconciliationPublisher.cs          # Publishes findings to notifications.reconciliation.queue
├── Infrastructure/
│   ├── PoisonPillGuard.cs                      # Kafka consumer protection — skips permanent errors, retries transient up to MaxPoisonRetries
│   ├── ElasticsearchHealthCheck.cs             # Readiness check for Elasticsearch connectivity
│   ├── HealthCheckResponseWriter.cs            # Structured JSON response for /health/* endpoints
│   ├── KafkaHealthCheck.cs                     # Readiness check for Kafka broker connectivity
│   ├── RabbitMqHealthCheck.cs                  # Readiness check for RabbitMQ connectivity
│   └── RedisHealthCheck.cs                     # Readiness check for Redis connectivity
├── Configuration/
│   ├── KafkaOptions.cs / KafkaTopicOptions.cs  # Includes ReplicationFactor, OutboxMaxRetries, MaxPoisonRetries
│   ├── RabbitMqOptions.cs / MinioOptions.cs
│   ├── ReconciliationJobOptions.cs
│   ├── MedicationCorrelationOptions.cs         # Drug-vital mappings + correlation window
│   ├── PatientOptions.cs                       # MRN prefix + digit count for sequence-based generation
│   ├── FhirOptions.cs                          # API key (single + rotation array), identifier systems, department/class maps, defaults
│   ├── JwtOptions.cs                           # Issuer, audience, signing key, expiration (default 8 hours)
│   └── DashboardOptions.cs                     # CORS origins for ward dashboard frontend
├── Sepsis/
│   ├── AlertCreationGuard.cs                   # Prevents creation of deprecated alert types (SEPSIS_WARNING)
│   ├── QsofaCalculator.cs                      # Pure static qSOFA scoring (3 criteria, no I/O)
│   ├── QsofaDetector.cs                        # Redis qSOFA state, QSOFA_SCREEN alert creation, evaluation persistence to qsofa_evaluations
│   └── SepsisAlertHandler.cs                   # Bridges SOFA_SEPSIS alert → SepsisBundleService
├── News2/
│   ├── News2Calculator.cs                      # Pure static NEWS2 scoring tables (no I/O)
│   └── News2Detector.cs                        # Redis parameter state, score persistence, alert creation
├── Gcs/
│   ├── GcsCalculator.cs                        # GCS total, classification, NEWS2/qSOFA/SOFA mappings
│   └── GcsDetector.cs                          # Redis component state, score persistence, gcs.scored outbox
├── Sofa/
│   ├── SofaCalculator.cs                       # Six organ-system SOFA scoring (0–4 each)
│   ├── SofaDetector.cs                         # Lab cache compose, baseline/delta, alert creation
│   ├── SofaLabCache.cs                         # Redis carry-forward with staleness classification
│   └── SofaVasopressorResolver.cs              # Vasopressor dose from MedicationAdministration + Redis cache
├── Services/MapCalculator.cs                   # MAP from systolic + diastolic BP
├── Elasticsearch/Documents/
│   ├── PatientEncounterDocument.cs
│   ├── ObservationDocument.cs
│   └── ClinicalAlertDocument.cs
├── Notifications/
│   └── RabbitMqTopologyProvisioner.cs          # Declares exchange, queues, DLQ bindings on startup
├── Storage/
│   └── MinioClientFactory.cs
├── DataLake/
│   ├── DataLakeOptions.cs                      # Flush thresholds and bucket settings
│   ├── DataLakeWriterService.cs                # consumer group: data-lake-writer; Kafka → Parquet → MinIO; graceful shutdown flush
│   └── ParquetFileBuilder.cs                   # Topic row models → Parquet byte arrays
├── Models/Records/
│   ├── Observation/ObservationRow.cs           # Parquet row contract for observation events
│   ├── Alert/AlertRow.cs                       # Parquet row contract for alert events
│   ├── Encounter/EncounterStatusRow.cs         # Parquet row contract for encounter status events
│   ├── Encounter/WardEncounterSummary.cs       # Denormalized row for ward encounter list
│   ├── Medication/CreateMedicationAdministrationRequest.cs
│   ├── Qsofa/QsofaCurrentResponse.cs
│   └── Sepsis/QsofaResult.cs, QsofaOutcome.cs  # qSOFA detector result and screening outcome enum
├── Data/
│   ├── AppDbContext.cs                         # EF Core context — entity configs, indexes, constraints
│   ├── Configurations/                         # IEntityTypeConfiguration per entity; ClinicalUserConfiguration, ClinicalAuditLogConfiguration, ClinicalSiteConfiguration, WardGatewayConfiguration, QsofaEvaluationConfiguration; ElasticsearchOptions, ElasticIndexOptions
│   └── Seed/
│       ├── DataSeeder.cs                       # Seeds patients, encounters, thresholds, observations
│       ├── GatewayRegistrySeeder.cs            # Seeds demo site (SITE-DEMO) and gateway (GW-ICU-3B) with fixed GUIDs
│       └── UserSeeder.cs                       # Seeds four demo users (nurse, physician, admin, integration)
├── Common/
│   ├── ApiResponse.cs                          # { success, statusCode, data, error } envelope
│   ├── PagedResult.cs / CursorPage.cs
│   └── Exceptions/
│       ├── NotFoundException.cs
│       ├── ConflictException.cs                # Thrown by encounter status machine
│       ├── DomainException.cs
│       └── ValidationException.cs
├── Middlewares/
│   ├── FhirApiKeyOrJwtMiddleware.cs            # Dual auth for /fhir/* routes: JWT bearer or X-Api-Key (multi-key rotation, constant-time compare) → Integration identity
│   ├── CorrelationIdMiddleware.cs
│   └── ExceptionHandlerMiddleware.cs
└── Migrations/

infra/
├── prometheus/
│   └── prometheus.yml                          # Scrape config for vigilcare_api /metrics
└── grafana/
    ├── provisioning/                           # Datasource + dashboard provider config
    └── dashboards/                             # vigilcare.json clinical dashboard

tests/
└── VigilCareClinicalAPI.Tests/
    ├── ObservationIngestTests.cs               # Ingest happy path, critical alert creation, discharged encounter rejection, idempotency
    ├── AlertLifecycleTests.cs                  # Acknowledge, resolve, escalation guard
    ├── NotificationPipelineTests.cs            # RabbitMQ topology, DLQ routing
    ├── ReconciliationTests.cs                  # Three reconciliation checks, deduplication, RabbitMQ publish
    ├── ObservabilityPhase8Tests.cs             # /metrics families and correlation header behavior
    ├── DataLakePhase9Tests.cs                  # Kafka → MinIO Parquet flow and schema checks
    ├── ClinicalDemographicsAndObservationTests.cs  # Patient/encounter enrichment, expanded observation alerts
    ├── WarningAlertTests.cs                    # WarningEvaluator — warning created, normal/critical skipped, idempotent
    ├── OrderLifecycleTests.cs                  # Orders API — create, list, record result, illegal transition 409
    ├── ValidationTests.cs                      # FluentValidation — empty fields, threshold ordering, order description
    ├── News2CalculatorTests.cs                 # Boundary tests for all seven NEWS2 scoring tables
    ├── News2DetectorTests.cs                   # NEWS2 detector — score tiers, alerts, idempotency, incomplete set
    ├── TrendCalculatorTests.cs                 # Pure unit tests — rate-of-change, threshold direction, describe
    ├── TrendDetectorTests.cs                   # Trend detector — rapid climb, stable, idempotent, non-trend code
    ├── AlertSuppressionTests.cs                # Suppression on acknowledge, read-side skip, TTL expiry
    ├── QsofaCalculatorTests.cs                 # Boundary tests for three qSOFA criteria
    ├── QsofaDetectorTests.cs                   # qSOFA detector — two-criteria QSOFA_SCREEN alert, normalization, idempotency
    ├── SepsisBundleTests.cs                    # Bundle creation from SOFA_SEPSIS, element completion, compliance outcomes
    ├── SepsisRefactorTests.cs                  # Sepsis-3 refactor — SIRS removal, qSOFA screen workflow, SOFA bundle trigger
    ├── AlertCreationGuardTests.cs              # Guard prevents deprecated SEPSIS_WARNING creation
    ├── ClinicalRefactorEndToEndTests.cs        # End-to-end scenario replay: qSOFA screen → SOFA labs → bundle
    ├── MedicationServiceTests.cs               # Medication CRUD, discharged encounter rejection, pagination
    ├── MedicationCorrelationTests.cs           # End-to-end warning/NEWS2 annotation with medication context
    ├── MedicationValidationTests.cs            # FluentValidation 400 on invalid medication requests
    ├── EncountersListTests.cs                  # Ward encounter list filters and summary fields
    ├── QsofaCurrentTests.cs                    # qSOFA current API — Redis state, criteria breakdown
    ├── GcsScoringTests.cs                      # GCS component scoring, alerts, NEWS2/qSOFA integration paths
    ├── SofaScoringTests.cs                     # SOFA organ scores, baseline, delta alerts, carry-forward, vasopressors
    ├── BackgroundServiceTests.cs                # Outbox relay, Kafka consumer, sepsis bundle monitor, reconciliation
    ├── ConcurrencyTests.cs                      # Parallel patient MRN, sepsis bundle, observation idempotency, encounter open
    ├── GapAnalysisFixTests.cs                  # Phase 22 — GCS history, qSOFA evaluation persistence/history, encounter timeline
    ├── GatewayRegistryTests.cs                 # Gateway register, heartbeat, API key auth, department filter
    ├── Helpers/GatewayAuthHelper.cs             # WithGatewayApiKey extension method for test clients
    ├── Auth/
    │   └── RbacTests.cs                        # RBAC — unauthenticated 401, nurse 403 on threshold write, admin audit log creation
    └── Fhir/
        └── FhirIngestTests.cs                  # FHIR R4 patient upsert idempotency, observation LOINC mapping, unknown code 422, transaction bundle

VigilCare.ClinicalContracts/                      # Phase 20 — shared sync DTOs (no ASP.NET dependency)
├── VigilCare.ClinicalContracts.csproj            # net8.0 class library, no NuGet packages
└── Sync/
    ├── ClinicalSyncBatchRequest.cs               # Batch upload envelope (batchReference, gatewayId, siteId, items)
    ├── SyncedObservation.cs                      # Per-observation sync item with idempotency key
    ├── SyncedAlertEvent.cs                       # Client-generated alert event
    ├── SyncedAlertAcknowledgment.cs              # Alert acknowledgment from ward
    ├── SyncedAlertResolution.cs                  # Alert resolution from ward
    └── GatewayHeartbeatRequest.cs                # Status + buffer depth + timestamp

VigilCare.ClinicalContracts.Tests/                # Contracts round-trip serialization tests
└── ClinicalContractsTests.cs

VigilCare.WardGateway/                            # Phase 21 — local-first ward edge API (separate DB/Redis/RabbitMQ)
├── Dockerfile
├── Program.cs
├── Common/                                        # ApiResponse envelope, CursorPage, PagedResult, domain exceptions
├── Data/
│   ├── GatewayDbContext.cs
│   └── Configurations/                           # snake_case mappings mirroring central API patterns
├── Domain/
│   ├── Entities/                                 # ReplicaPatient, ReplicaEncounter, LocalObservation, LocalClinicalAlert, BufferedSyncItem, SyncOutboxEntry, GatewaySyncState, ReplicaAlertThreshold
│   └── Enums/                                    # AlertType, AlertSeverity, AlertStatus, EncounterStatus, EncounterType, BufferedSyncItemType, SyncOutboxStatus, ObservationSource, Department
├── Models/Records/ThresholdCacheEntry.cs
├── Models/Records/Observation/IngestObservationRequest.cs
├── Models/Records/Alert/AcknowledgeAlertRequest.cs
├── Models/Records/Encounter/                      # EncounterDetail, WardEncounterSummary
├── Models/Records/LocalIngestResult.cs
├── Models/Central/CentralSyncDtos.cs              # DTOs for central API sync responses
├── Models/Central/CentralApiJson.cs
├── Validators/IngestObservationRequestValidator.cs
├── Validators/AcknowledgeAlertRequestValidator.cs
├── Services/
│   ├── PlausibilityValidator.cs
│   ├── LocalObservationService.cs
│   ├── LocalWarningEvaluator.cs
│   ├── LocalAlertService.cs
│   ├── LocalPagingPublisher.cs
│   ├── ObservationQueryService.cs
│   ├── EncounterReadService.cs
│   └── BufferedSyncWriter.cs
├── Controllers/
│   ├── ObservationsController.cs
│   ├── AlertsController.cs
│   ├── EncountersController.cs
│   └── CentralRequiredController.cs
├── Notifications/RabbitMqTopologyProvisioner.cs
├── Middlewares/ExceptionHandlerMiddleware.cs
├── BackgroundService/
│   ├── EncounterReplicaSyncService.cs             # Syncs patient/encounter data from central API on startup
│   ├── ThresholdCacheLoader.cs                    # Pre-loads alert thresholds from central API into Redis
│   ├── CentralReachabilityService.cs              # Periodic central API health check (sets online/offline state)
│   ├── GatewayHeartbeatService.cs                 # Reports gateway status and buffer depth to central API
│   ├── SyncUploaderService.cs                     # Uploads buffered observations/alerts to central API when online
│   ├── LocalPagingWorkerService.cs
│   └── LocalEscalationWorkerService.cs
├── Configurations/                               # GatewayOptions, CentralApiOptions, RabbitMqOptions, SuppressionOptions
├── Infrastructure/                               # Health checks (Redis, RabbitMQ, encounter replica ready)
└── Migrations/                                   # InitialGatewaySchema

VigilCare.WardGateway.Tests/                       # Phase 21 — ward gateway integration tests
├── VigilCare.WardGateway.Tests.csproj
├── Fixtures/
│   ├── GatewayApiFixture.cs                       # WebApplicationFactory with Testcontainers (PostgreSQL, Redis, RabbitMQ)
│   └── GatewayIntegrationCollection.cs
├── Helpers/
│   ├── GatewayDbResetHelper.cs                    # Database reset between tests
│   └── GatewayTestSeeder.cs                       # Seeds test patients, encounters, thresholds
├── WardGatewayLocalPathTests.cs                   # Local observation ingest, warning alerts, buffered sync items
└── WardGatewayPartitionTests.cs                   # Network partition simulation — offline buffering and sync upload

VigilCare.Simulator/                              # Phase 16 — console replay simulator (HTTP-only, no direct DB/Kafka)
├── Program.cs                                    # CLI: replay, replay-all, validate, dry-run
├── Commands/                                     # System.CommandLine command handlers
├── Client/VigilCareApiClient.cs                  # Typed HTTP client for all API endpoints (incl. GCS, SOFA)
├── Engine/ReplayEngine.cs                        # Scenario replay with speed multiplier + event logging
├── Output/SimulatorConsole.cs                    # Colored output with GCS/SOFA score display
├── Polling/ApiPoller.cs                          # Optional post-event alert/score/bundle/GCS/SOFA polling
├── Scenarios/                                    # schema.json, ScenarioLoader, ScenarioValidator
└── Scenarios/List/                             # Eleven sample scenarios (sepsis, GCS, SOFA, NEWS2, stable, …)

vigilcare-dashboard/                              # Phases 17–19, 22, 27–28, 31 — Vue 3 ward dashboard SPA
├── src/
│   ├── api/                                      # HTTP client (auto Bearer header), encounters, clinical (GCS, SOFA, qSOFA history), alerts, analytics, sepsis, normalize
│   ├── components/
│   │   ├── alerts/                               # AlertCard, AcknowledgeModal (role-aware), CriticalAlertBanner (browser notifications + audible tone)
│   │   ├── charts/                               # SofaHistory, GcsHistory, QsofaHistory, VitalChart with medication markers
│   │   ├── departments/                          # DepartmentCard, AcuityBar (unit-level snapshot)
│   │   ├── feedback/                             # FeedbackButtons, FeedbackSummary
│   │   ├── layout/                               # AppShell, AppHeader, AppSidebar
│   │   ├── patient/                              # GcsEntryForm, SofaScorePanel, PatientBanner, EncounterTimeline, VitalsEntryForm, VitalsPanel, AlertsList
│   │   ├── replay/                               # ReplayControls
│   │   ├── sepsis/                               # SepsisBundleTable, SepsisBundleRow, SepsisBundleCard (countdown timer)
│   │   ├── ward/                                 # WardTable (sortable headers), PatientRow, PatientCard, WardToolbar, SortableHeader, HandoffReport (SBAR + print)
│   │   └── ui/                                   # Button, Card, Badge, Skeleton, EmptyState
│   ├── composables/                              # useChartData, useReplayControls, usePolling, useFeedback, useGcs, useSofa, chartFormat, patientFormat, timelineFormat, chartMedications, wardSort, wardFilter, departmentFormat, sepsisFormat, alertAcknowledge, criticalAlertDetect, useAlertNotification, useCriticalAlertPolling, handoffReport, vitalsForm
│   ├── plugins/                                  # medicationMarkerPlugin (Chart.js plugin for medication administration markers on vital charts)
│   ├── stores/                                   # Pinia — ward (sort + filter + search), alerts (banner + polling), settings (sort prefs + sound mute), feedback, scoring, auth, departments, sepsis
│   ├── views/                                    # LoginView, WardDashboard, PatientDetail, AlertCenter, FeedbackSummary, DepartmentOverviewView, SepsisBoardView
│   └── __tests__/                                # Vitest — tests (store, feedback, replay, charts, alerts, ward, GCS, SOFA, qSOFA, PatientBanner, EncounterTimeline, patientFormat, timelineFormat, chartMedications, wardSort, wardFilter, departmentFormat, sepsisFormat, alertAcknowledge, criticalAlertDetect, HandoffReport, handoffReport, VitalsEntryForm, vitalsForm, useAlertStore, useWardStore, DepartmentOverviewView, SepsisBoardView, AcknowledgeModal, CriticalAlertBanner)
├── vite.config.js
└── README.md                                     # Dev quick start → docs/dashboard-guide.md

scripts/
├── run-api-redis-tests.sh                      # Phase 1 — patient/encounter/threshold + Redis cache
├── run-kafka-outbox-tests.sh                   # Phase 3 — outbox relay and Kafka topics
├── run-elasticsearch-analytics-tests.sh        # Phase 4 — Elasticsearch CQRS projection
├── run-sepsis-sirs-tests.sh                    # Phase 5 — legacy SIRS tests (now qSOFA-only)
├── run-notification-pipeline-tests.sh            # Phase 6 — RabbitMQ paging, DLQ, discharge summary
├── run-reconciliation-tests.sh                 # Phase 7 — reconciliation scheduler checks
├── run-phase8-verification.sh                  # Phase 8 — Prometheus metrics, alerts_unacknowledged_gauge, correlation headers
├── run-phase9-verification.sh                  # Phase 9 — data lake tests, Kafka offsets, MinIO Parquet, DuckDB schema
├── run-phase10-verification.sh                 # Phase 10 — 12 Redis thresholds, clinical enrichment, ES pipeline, integration tests
├── run-phase11-verification.sh                 # Phase 11 — warning alerts, orders API, validation, integration tests
├── run-phase12-verification.sh                 # Phase 12 — NEWS2 end-to-end pipeline, API, ES, Prometheus, integration tests
├── run-phase13-verification.sh                 # Phase 13 — trend detection, alert suppression, consumer lag, integration tests
├── run-phase14-verification.sh                 # Phase 14 — qSOFA, sepsis bundle compliance, integration tests
├── run-phase15-verification.sh                 # Phase 15 — medication administration + correlation annotations
├── run-phase25-verification.sh                 # Phase 25 — GCS scoring integration tests + manual API checks
├── run-phase26-verification.sh                 # Phase 26 — SOFA scoring integration tests + baseline/delta API checks
├── run-phase27-verification.sh                 # Phase 27 — Sepsis-3 refactor: SIRS removal, QSOFA_SCREEN, SOFA bundle trigger
├── run-phase28-verification.sh                 # Phase 28 — Frontend GCS entry + SOFA display + sepsis UI refactor
├── run-phase20-verification.sh                 # Phase 20 — Gateway registry tests + site/gateway/heartbeat curl checks
├── run-phase21-verification.sh                 # Phase 21 — Ward gateway local-first path, partition tests, sync upload
├── run-phase22-verification.sh                 # Phase 22 — Dashboard gap analysis fixes (SOFA/GCS/qSOFA history, patient banner, timeline, medication markers)
├── run-phase24-verification.sh                 # Phase 24 — Ward outage reconnect scenario (central + gateway replay, ack sync)
├── run-phase29-verification.sh                 # Phase 29 — Simulator scenario expansion + clinical validation
├── run-phase30-verification.sh                 # Phase 30 — FHIR R4 ingest integration tests + manual bundle/metadata checks
└── run-phase31-verification.sh                 # Phase 31 — RBAC integration tests + JWT login + audit log query

docs/
├── plans/                                      # Phase implementation and verification guides
├── clinical-testing-guide.md                   # Doctor/nurse guide — alert review & feedback sessions
├── dashboard-guide.md                          # VigilCare Dashboard user guide (ward, patient detail, charts)
├── dashboard-gap-analysis.md                   # Comprehensive gap analysis — P0–P5 clinical usefulness assessment
├── patient-encounter-api-lifecycle.md          # Full API walkthrough: registration → active stay → discharge
├── simulator-guide.md                          # VigilCare.Simulator user guide
├── integration/
│   └── mirth-fhir-channels.md                  # Mirth Connect HL7v2→FHIR channel mapping (ADT A01/A03/A08, ORU R01)
├── decisions/
│   ├── data-lake-design.md                     # Parquet vs JSON, partitioning, replay rationale
│   ├── sepsis-engine-design.md                 # Sepsis-3 qSOFA screening and idempotent alert design
│   ├── medication-correlation-design.md        # Drug-vital mapping and annotation rationale
│   └── clinical-refactor-sofa-gcs.md           # Interview Q&A: why SIRS→SOFA, carry-forward, GCS dependency chain
├── docker-compose-usage-and-troubleshooting.md
└── vigilcare-clinical-api-prd.md               # Product requirements and phase roadmap

---

Architecture Decisions

Synchronous vs Asynchronous Alert Detection — The Split

Critical threshold breaches are detected synchronously within the ingest transaction. A critical potassium of 2.1 mEq/L is immediately life-threatening. If the API returns 201 Created before generating the alert and the Kafka consumer lags by 30 seconds, a patient could deteriorate during that window. The synchronous check costs one additional Redis read per observation on the hot path — acceptable for correctness.

A warning heart rate of 95 bpm warrants attention but is not an emergency. The additional latency of Kafka consumer processing is clinically acceptable for a warning.

This is the architectural decision that separates thinking about healthcare systems from thinking about financial systems. The tradeoff is latency for correctness, and the correctness definition is clinical, not technical.

Encounter as the Aggregate Root (Not Patient)

Observations, alerts, and orders belong to an encounter, not directly to a patient. A patient's blood pressure taken during a 2022 admission belongs to that admission. This bounds queries naturally: "show me all observations for this encounter" is a bounded query. "Show me all observations ever recorded for this patient" is a cross-encounter aggregation that belongs in the data lake.

Redis for Seven Distinct Purposes

Redis serves seven independent roles with different semantics:

1. Threshold cache: write-through invalidation on every threshold update. Staleness here has clinical consequences — a stale threshold could suppress a critical alert. TTL expiry is not sufficient; invalidation must be immediate on write.

2. qSOFA sliding window: SET qsofa:{encounterId}:{code} EX 1800. The 30-minute TTL is a clinical parameter — a respiratory rate that was abnormal 31 minutes ago stops contributing to the qSOFA count without any cleanup job. When a value normalizes, the key is explicitly deleted rather than waiting for TTL — a systolic BP that recovers from 90 to 120 should immediately reduce the qSOFA count.

3. NEWS2 parameter state: SET news2:{encounterId}:{code} with a 4-hour TTL. Each of the seven NEWS2 parameters is scored individually and stored in Redis; MGET across all seven keys determines completeness. An incomplete set (fewer than seven present keys) does not produce a score — expired parameters must be re-recorded before the aggregate is computed.

4. GCS component state: SET gcs:{encounterId}:{component} tracking Eye, Verbal, and Motor components. All three must be present before a total score is computed. Completion triggers gcs.scored for SOFA CNS re-scoring.

5. SOFA lab cache: SET sofa:{encounterId}:{code} with carry-forward semantics (configurable 24-hour TTL). Labs are classified as CURRENT (< 12h), STALE (12–24h), or EXPIRED (> 24h). Stale values are still used for scoring but flagged in staleness metadata. This enables SOFA scoring on wards where labs are drawn every 6–12 hours, not continuously.

6. Trend history: sliding-window observation history for rate-of-change detection. Five vital parameters tracked for velocity thresholds.

7. Alert suppression windows: SET suppress:{encounterId}:{alertType} with a configurable TTL (default 30 min). Set on acknowledge of suppressible alerts; checked by WarningEvaluator and News2Detector before creating new warning alerts. Critical alerts are never suppressed.

Outbox Pattern

Observation and alert writes use the transactional outbox: the outbox_events row is inserted in the same transaction as the domain record. The relay publishes to Kafka asynchronously using an idempotent producer (EnableIdempotence = true) — the broker deduplicates in-flight retries using producer ID and sequence number. This prevents message loss when Kafka is temporarily unavailable and prevents phantom messages when the transaction rolls back. Events that repeatedly fail Kafka delivery (network partition, broker-level rejection) are retried up to OutboxMaxRetries (default 10) before being marked permanently failed — acting as a dead-letter mechanism that prevents a single poisoned event from blocking the entire relay. The relay uses FOR UPDATE SKIP LOCKED so multiple instances can run concurrently without contention.

Kafka Partition Key: encounterId

All events for the same encounter land on the same partition. The sepsis engine requires this: if observations from the same patient arrive on different partitions, they may be consumed out of order and simultaneous qSOFA criteria could be missed. Six partitions balance parallelism against per-encounter ordering guarantees.

Elasticsearch as a CQRS Read Projection

PostgreSQL is always the write side and the source of truth. Elasticsearch is a denormalized, queryable projection optimized for the queries clinicians actually run. The population endpoint — "how many active patients have a heart rate above 100 in the last hour" — is a numeric range aggregation across potentially millions of observation rows. Running this against PostgreSQL on the operational database would compete with ingest writes. Elasticsearch's aggregation engine is purpose-built for this pattern.

The replay: stop EsIndexerService → delete both indices → reset consumer group offset to 0 → restart → wait for rebuild → verify document count matches PostgreSQL row count. This is the proof that Elasticsearch is a projection and not a source of truth, and the clearest demonstration of why Kafka retains events after consumption.

DLQ as a Clinical Escalation Protocol

The five-minute escalation is not a retry — it is a clinical workflow. When an alert is created, the paging worker sends a page to the attending physician. If no acknowledgment arrives within five minutes, the message NACKs to alerts.paging.dlq with x-message-ttl = 300000ms. After TTL expires, the DLQ re-routes to alerts.escalation.queue and the on-call backup is paged. During graceful shutdown, cancellation of the in-flight wait loop is treated as non-failure and the message is NACKed with requeue=true, preventing false escalation during deploy/restart windows. This pattern has no equivalent in Kafka — Kafka has no concept of per-message TTL or conditional re-routing based on consumer acknowledgment.

Why Not a Time-Series Database for Observations?

A medium hospital with 200 concurrent inpatients at five observations per patient per minute produces approximately 17 observations per second at steady state. PostgreSQL with the composite index (encounter_id, observation_code, recorded_at DESC) handles this volume with headroom. TimescaleDB would be the correct next step at 10,000+ observations/second — it is PostgreSQL with automatic time partitioning, meaning the query layer would not change. The Parquet data lake handles the analytics workload that would otherwise stress the operational database over a 10-year horizon.

Two-Tier Sepsis Detection (Sepsis-3: qSOFA Screen → SOFA Confirmation)

The sepsis pathway follows the Sepsis-3 consensus (2016), replacing the older SIRS-based approach:

1. Screening (qSOFA): SepsisEngineService evaluates three bedside criteria (respiratory rate ≥ 22, systolic BP ≤ 100, altered mentation via GCS < 15). When ≥ 2 are active, a QSOFA_SCREEN (WARNING-level) alert is created, recommending SOFA lab orders.

2. Confirmation (SOFA): SofaScoringService scores six organ systems from labs and vitals. When SOFA delta ≥ 2 from baseline, a SOFA_SEPSIS (CRITICAL) alert fires and triggers the sepsis bundle via SepsisAlertHandler.

This two-tier design prevents false-positive bundle activations — SIRS criteria (temperature, heart rate, respiratory rate, WBC) were too non-specific, triggering bundles for post-surgical inflammation, anxiety, and viral infections. SOFA measures actual organ dysfunction, making the bundle trigger clinically meaningful. The legacy SEPSIS_WARNING and QSOFA_WARNING alert types are retained (marked [Obsolete]) for historical queries but can no longer be created.

---

Getting Started

Prerequisites

• .NET 8 SDK
• Docker and Docker Compose

Start Infrastructure

Central stack only (default — no Compose profile):

docker compose up -d

Ward gateway stack (separate PostgreSQL, Redis, RabbitMQ, and gateway API on port 5081):

docker compose --profile ward-gateway up -d

Everything (central + ward):

docker compose --profile full up -d

Ward services use Compose profiles and do not start with a plain docker compose up. See docs/docker-compose-usage-and-troubleshooting.md §10.

All services join the vigilcare_net bridge network so containers can reach each other by service name (e.g. Grafana → http://prometheus:9090). Connection strings in appsettings.json use host ports when running dotnet run on your machine.

Service	Host Port	Notes
PostgreSQL 16	5436	Database: vigilcare, user: postgres, password: password
Redis 7	6382	No auth
Seq	5345	UI at http://localhost:5345 — login: admin / admin
Kafka 3.7	9092	KRaft mode, no Zookeeper
Elasticsearch 8.13	9200	Security disabled for development
RabbitMQ 3.13	5674 (AMQP), 15674 (UI)	login: guest / guest
MinIO	9005 (S3 API), 9006 (console)	login: minioadmin / minioadmin
Prometheus 2.52	9101	UI at http://localhost:9101 — scrapes GET /metrics on the API
Grafana 10.4	3101	UI at http://localhost:3101 — login: admin / admin

Ward gateway stack (--profile ward-gateway or full):

Service	Host Port	Notes
Ward PostgreSQL 16	5437	Database: vigilcare_ward, user: postgres, password: password
Ward Redis 7	6383	No auth
Ward RabbitMQ 3.13	5675 (AMQP), 15675 (UI)	login: guest / guest
Ward Gateway API	5081	VigilCare.WardGateway — local-first clinical path (Phase 21)

Seq first-run: SEQ_FIRSTRUN_ADMINPASSWORD=admin is set in docker-compose.yml. This password is only applied on the very first container start (when the /data volume is empty). After initialization, the password is stored in the volume and this env var is ignored.

Docker notes for Linux

Prometheus scrapes the API using host.docker.internal:5270. On Linux, two things are required:

1. In docker-compose.yml under prometheus:

   extra_hosts:
     - "host.docker.internal:host-gateway"
   

2. Run the API bound to all interfaces (not only loopback), so containers can reach it:
   • Use http://0.0.0.0:5270 (or ASPNETCORE_URLS=http://0.0.0.0:5270)

Without this, Prometheus may show target errors like:

• lookup host.docker.internal ... no such host (DNS mapping missing), or
• dial tcp 172.17.0.1:5270: connect: connection refused (API bound only to 127.0.0.1)

For full Docker troubleshooting and recovery steps, see:

• docs/docker-compose-usage-and-troubleshooting.md

Install and Run

cd VigilCareClinicalAPI
dotnet restore
dotnet run

On startup the application:

1. Runs EF Core migrations
2. Seeds two patients (with blood type, allergies, emergency contact), one active inpatient encounter each (with room/bed and admission reason), twelve alert thresholds, sample observations, and four clinical users (nurse, physician, admin, integration)
3. Pre-loads all thresholds into Redis
4. Provisions Kafka topics and Elasticsearch indices
5. Declares the RabbitMQ exchange and queue topology
6. Starts all background consumers (outbox relay, ES indexer, sepsis engine with qSOFA screening, warning evaluator, NEWS2 scoring, GCS scoring, SOFA scoring, trend analyzer, notification workers, data lake writer, reconciliation scheduler, sepsis bundle monitor)
7. Starts Prometheus metric collectors (unacknowledged alerts, outbox pending, Kafka consumer lag, ward gateway fleet health)

Swagger UI is available at http://localhost:5270/swagger in Development (API binds to 0.0.0.0:5270 per launchSettings.json).

Health checks (anonymous, no JWT required):

• GET /health/live — liveness probe (always 200 if process is running)
• GET /health/ready — readiness probe (checks PostgreSQL, Redis, Kafka, RabbitMQ, Elasticsearch)

Run the Simulator

With the API running, replay a scenario from the repository root:

dotnet run --project VigilCare.Simulator -- replay \
  VigilCare.Simulator/Scenarios/List/uti-sepsis-elderly-01.json \
  --speed 60 --poll

Other commands: validate <file>, dry-run <file>, replay-all <directory>. See docs/simulator-guide.md for the full user guide.

Ward outage reconnect (Phase 24): scenario ward-outage-reconnect-01.json exercises critical hyperkalemia alerting and nurse acknowledgment during a central outage, then sync back to central when connectivity returns. Manual procedure in docs/simulator-guide.md §10; automated end-to-end check:

./scripts/run-phase24-verification.sh

Requires Docker Compose (central API, ward gateway stack) and a running central API on http://localhost:5270. Use SKIP_DOCKER=1 when the stack is already up. Notes from verification runs: docs/resilience/phase-24-verification-notes.md.

Run the Dashboard

With the API running, start the Vue frontend:

cd vigilcare-dashboard
npm install
npm run dev

Open http://localhost:5173 — log in with a demo account (e.g. nurse.demo / DemoNurse1!). Virtual Ward lists active patients sorted by NEWS2 score. Click a row for patient detail (vitals, alerts, charts, replay scrubbing, alert reasoning). Use Alert Center for hospital-wide triage. After reviewing alerts, rate them with the six feedback buttons and export results from Feedback Summary (/feedback).

Replay a simulator scenario in another terminal to watch charts and alerts populate in real time. Run dashboard tests with cd vigilcare-dashboard && npm test. See docs/dashboard-guide.md for technical documentation and docs/clinical-testing-guide.md for structured clinician evaluation sessions.

Run Tests

dotnet test

Integration tests use WebApplicationFactory with a Testing environment and Testcontainers where needed (PostgreSQL, Redis, Kafka, RabbitMQ, Elasticsearch, MinIO). No manual infrastructure setup is required for dotnet test.

Test class	Phase	Coverage
ObservationIngestTests	2	Ingest happy path, critical alert creation, discharged encounter rejection, idempotency
AlertLifecycleTests	2	Acknowledge, resolve, escalation guard
SepsisRefactorTests	27	Sepsis-3 refactor — SIRS removed, qSOFA creates QSOFA_SCREEN, SOFA delta triggers bundle
AlertCreationGuardTests	27	Guard prevents creation of deprecated SEPSIS_WARNING alerts
ClinicalRefactorEndToEndTests	29	End-to-end scenario replay: qSOFA screen → SOFA labs → SOFA_SEPSIS → bundle
NotificationPipelineTests	6	RabbitMQ topology, DLQ routing, paging
ReconciliationTests	7	Three reconciliation checks, deduplication, RabbitMQ publish
ObservabilityPhase8Tests	8	All ten /metrics families, correlation headers, ingest counter increment
DataLakePhase9Tests	9	Kafka → MinIO Parquet flow and schema checks
ClinicalDemographicsAndObservationTests	10	Patient clinical fields, encounter enrichment, expanded observation codes, critical glucose alert
WarningAlertTests	11	WarningEvaluator — warning HR alert, normal/critical skipped, duplicate idempotent
OrderLifecycleTests	11	Orders API create, list, record result, cancel-resulted 409
ValidationTests	11	FluentValidation 400 on empty first name, invalid threshold order, empty order description
News2CalculatorTests	12	Boundary tests for all seven NEWS2 scoring tables and risk-level determination
News2DetectorTests	12	NEWS2 detector — score tiers, alert creation, incomplete parameters, idempotency
TrendCalculatorTests	13	Pure unit tests — delta/time rate, SPO2/BP decline direction, describe formatting
TrendDetectorTests	13	Trend detector — rapid HR climb alert, stable high HR, idempotency, non-trend code
AlertSuppressionTests	13	Acknowledge sets Redis key, suppressed warning skipped, critical/NEWS2 emergency never suppressed, TTL expiry
QsofaCalculatorTests	14	Boundary tests for three qSOFA criteria (RESP_RATE, SYSTOLIC_BP, AVPU)
QsofaDetectorTests	14	qSOFA detector — two-criteria QSOFA_SCREEN alert, normalization key delete, idempotent duplicate, non-qSOFA code ignored
SepsisBundleTests	14	Bundle creation from SOFA_SEPSIS, four auto-orders, element completion, compliant/non-compliant outcomes, monitor marks overdue bundles, idempotency
MedicationServiceTests	15	Medication create/list on active encounter, discharged encounter 409, pagination, since filter
MedicationCorrelationTests	15	Warning and NEWS2 alert details annotated when correlated drug administered
MedicationValidationTests	15	FluentValidation 400 on empty drug name, zero dose, future administeredAt
EncountersListTests	—	Ward encounter list — status/department filters, summary fields
QsofaCurrentTests	—	GET /qsofa/current — criteria count and breakdown from Redis
GcsScoringTests	25	GCS component scoring, classification, alerts, CNS integration with SOFA
SofaScoringTests	26	SOFA organ scores, baseline eligibility, delta alerts, carry-forward, vasopressors
GatewayRegistryTests	20	Gateway register, heartbeat status/buffer, API key auth 401, degraded status, department filter
ClinicalContractsTests	20	ClinicalSyncBatchRequest JSON round-trip serialization
FhirIngestTests	30	FHIR R4 patient upsert idempotency, LOINC observation mapping, unknown code 422, transaction bundle
RbacTests	31	Unauthenticated 401, nurse 403 on threshold write, admin threshold update with audit log creation, alert acknowledge uses authenticated user
BackgroundServiceTests	—	Outbox relay, Kafka consumer, sepsis bundle monitor, reconciliation
ConcurrencyTests	—	Parallel patient registration unique MRNs, parallel sepsis alerts single bundle, parallel observation idempotency, parallel encounter open duplicate rejection
GapAnalysisFixTests	22	GCS history API, qSOFA evaluation persistence and history API, encounter timeline with patient data
WardGatewayLocalPathTests	21	Local observation ingest, critical/warning alert creation, buffered sync item generation
WardGatewayPartitionTests	21	Network partition simulation — offline buffering, sync upload to central API, encounter replica sync

Verification Scripts

With the API running (dotnet run) and Docker Compose up:

./scripts/run-phase22-verification.sh  # Dashboard gap analysis fixes — SOFA/GCS/qSOFA history, patient banner, timeline
./scripts/run-phase21-verification.sh  # Ward gateway local-first path, partition tests, sync upload verification
./scripts/run-phase24-verification.sh  # Ward outage reconnect — gateway replay, local ack, central sync after restart
./scripts/run-phase20-verification.sh  # Gateway registry tests, site/gateway/heartbeat API verification
./scripts/run-phase8-verification.sh   # Prometheus target UP, ten metrics, alerts_unacknowledged_gauge live update
./scripts/run-phase9-verification.sh   # DataLakePhase9Tests, Kafka consumer group, MinIO Parquet, DuckDB schema
./scripts/run-phase10-verification.sh  # 12 Redis thresholds, clinical enrichment, ES pipeline, Phase 10 integration tests
./scripts/run-phase11-verification.sh  # Warning alert pipeline, orders API, FluentValidation, Phase 11 integration tests
./scripts/run-phase12-verification.sh  # NEWS2 end-to-end pipeline, API, Elasticsearch, Prometheus, Phase 12 integration tests
./scripts/run-phase13-verification.sh  # Trend detection, alert suppression, consumer lag, Phase 13 integration tests
./scripts/run-phase14-verification.sh  # qSOFA, sepsis bundle compliance, Phase 14 integration tests
./scripts/run-phase15-verification.sh  # Medication administration + correlation annotation pipeline
./scripts/run-phase27-verification.sh  # Sepsis-3 refactor: SIRS removal, QSOFA_SCREEN, SOFA bundle trigger
./scripts/run-phase30-verification.sh  # FHIR R4 ingest integration tests + manual bundle/metadata checks
./scripts/run-phase31-verification.sh  # RBAC integration tests + JWT login + audit log query

Phase 25 — GCS scoring (requires running API + Docker Compose; set an active encounter UUID):

export ENCOUNTER_ID=$(docker compose exec -T postgres psql -U postgres -d vigilcare -t -A \
  -c "SELECT id FROM encounters WHERE status = 'ACTIVE' LIMIT 1;")
./scripts/run-phase25-verification.sh

Phase 26 — SOFA scoring (same prerequisites; script polls for async Kafka scoring):

export ENCOUNTER_ID=$(docker compose exec -T postgres psql -U postgres -d vigilcare -t -A \
  -c "SELECT id FROM encounters WHERE status = 'ACTIVE' LIMIT 1;")
./scripts/run-phase26-verification.sh

Phase 13 unit/integration tests only:

dotnet test --filter "FullyQualifiedName~Trend|FullyQualifiedName~Suppression"

Phase 15 unit/integration tests only:

dotnet test --filter "FullyQualifiedName~Medication"

Phase 21 ward gateway tests only:

dotnet test --filter "FullyQualifiedName~WardGateway"

Phase 20 gateway tests only:

dotnet test --filter "FullyQualifiedName~GatewayRegistry|FullyQualifiedName~ClinicalContracts"

Phase 31 RBAC tests only:

dotnet test --filter "FullyQualifiedName~Rbac"

Phase 22 dashboard gap analysis tests only:

dotnet test --filter "FullyQualifiedName~GapAnalysisFix"

Per-phase test runners (subset of dotnet test):

./scripts/run-api-redis-tests.sh
./scripts/run-kafka-outbox-tests.sh
./scripts/run-elasticsearch-analytics-tests.sh
./scripts/run-sepsis-sirs-tests.sh
./scripts/run-notification-pipeline-tests.sh
./scripts/run-reconciliation-tests.sh

Phase 9 optional tools (install without sudo):

# MinIO client — object listing and download
mkdir -p ~/.local/bin
curl -fsSL https://dl.min.io/client/mc/release/linux-amd64/mc -o ~/.local/bin/mc
chmod +x ~/.local/bin/mc

# DuckDB — query Parquet files locally
curl https://install.duckdb.org | sh
export PATH="$HOME/.duckdb/cli/latest:$HOME/.local/bin:$PATH"

See docs/plans/phase-8-plan.md through docs/plans/phase-12-plan.md for manual Grafana, Seq, Kafka replay, and DuckDB query examples.

---

Prometheus Metrics

GET /metrics exposes application metric families registered in ClinicalMetrics. Three background collectors poll PostgreSQL and Kafka every 30 seconds; counters and histograms are updated inline during request handling and background processing.

Metric	Type	Labels	Source
observations_ingested_total	Counter	observation_code, source	ObservationService on each committed observation
observation_ingest_duration_seconds	Histogram	—	ObservationService — full ingest transaction to COMMIT
clinical_alerts_total	Counter	alert_type, severity	ObservationService, QsofaDetector, News2Detector, TrendDetector, SofaDetector, WarningEvaluator
qsofa_detections_total	Counter	—	QsofaDetector — only on successful idempotent QSOFA_SCREEN insert
sepsis_bundle_compliance_total	Counter	status	SepsisBundleService — on bundle completion (COMPLIANT, NON_COMPLIANT)
news2_scores_total	Counter	risk_level	News2Detector — on each persisted score (LOW, MEDIUM, HIGH, …)
news2_scoring_duration_seconds	Histogram	—	News2Detector — Redis update through score persistence
gcs_scores_total	Counter	classification	GcsDetector — on each persisted score (MILD, MODERATE, SEVERE)
sofa_scores_total	Counter	has_delta_alert	SofaDetector — on each persisted score (true / false)
sofa_scoring_duration_seconds	Histogram	—	SofaDetector — full SOFA compose + persist
trend_alerts_total	Counter	observation_code	TrendDetector — on each RAPID_DETERIORATION alert created
trend_analysis_duration_seconds	Histogram	—	TrendDetector — per-observation trend evaluation
alert_suppressions_total	Counter	alert_type	AlertSuppressionService — on each suppression window set after acknowledge
escalations_total	Counter	—	EscalationWorkerService on DLQ escalation
alerts_unacknowledged_gauge	Gauge	—	AlertsUnacknowledgedCollector — open CRITICAL alerts older than 5 minutes
outbox_pending_events	Gauge	—	OutboxPendingCollector — unprocessed outbox rows
kafka_consumer_lag	Gauge	consumer_group	KafkaConsumerLagCollector — es-indexer, sepsis-engine, notification-publisher, data-lake-writer
fhir_ingest_total	Counter	resource_type, outcome	FhirIngestController — per resource type (Patient, Encounter, Observation, MedicationAdministration, Bundle) with success / error outcome
fhir_read_total	Counter	resource_type, interaction, outcome	FhirReadController — per resource type (Patient, Encounter) with interaction (read, search) and success outcome
authorization_failures_total	Counter	permission, role	PermissionAuthorizationHandler — authorization denials by required permission and user role
fhir_mapping_errors_total	Counter	resource_type	FhirExceptionFilter — mapping/validation failures by resource type
ward_gateways_offline_gauge	Gauge	site_code	WardGatewayMetricsCollector — count of gateways with status OFFLINE or DEGRADED per site
ward_gateway_buffer_depth	Gauge	gateway_code, department	WardGatewayMetricsCollector — reported unsynced event count per gateway
kafka_poison_pills_skipped_total	Counter	consumer_group, topic	PoisonPillGuard — messages skipped as permanently un-processable (malformed JSON, format errors, or transient failures exceeding MaxPoisonRetries)

Prometheus scrapes the API via infra/prometheus/prometheus.yml (job: vigilcare_api → host.docker.internal:5270). Grafana loads the clinical dashboard from infra/grafana/dashboards/vigilcare.json.

---

API Reference

All endpoints are prefixed /api/v1. Responses follow the standard envelope:

{ "success": true, "statusCode": 200, "data": {}, "error": null }

Error response:

{
  "success": false,
  "statusCode": 422,
  "data": null,
  "error": {
    "message": "Observation value exceeds plausible range for this code.",
    "code": "OBSERVATION_OUT_OF_PLAUSIBLE_RANGE"
  }
}

Patients

Method	Path	Description
POST	/patients	Register a patient; generates MRN
GET	/patients	Paginated list; optional q search by name (ILIKE) or MRN (exact)
GET	/patients/{id}	Patient detail with active encounter summary

POST body:

Field	Type	Required	Description
firstName	string	yes
lastName	string	yes
dateOfBirth	date	yes
gender	string	yes
bloodType	string	no	Clinical notation: A+, O-, AB-, etc.
allergies	string	no	Free-text allergy list
emergencyContactName	string	no
emergencyContactPhone	string	no

Encounters

Method	Path	Description
GET	/encounters	Paginated ward list with clinical summaries; optional status, department filters
POST	/patients/{id}/encounters	Open an encounter
GET	/encounters/{id}	Encounter detail with recent observations and open alerts
PATCH	/encounters/{id}/status	Advance encounter status
GET	/encounters/{id}/timeline	Merged chronological view: status changes, observations, alerts
GET	/encounters/{id}/qsofa/current	Current qSOFA active criteria count (0–3) from Redis
GET	/encounters/{id}/qsofa/history	Cursor-paginated qSOFA evaluation history

GET /encounters query params: status (DB literal, e.g. ACTIVE), department (DB literal, e.g. ICU), page, pageSize

Ward summary fields: encounterId, patientId, mrn, firstName, lastName, roomBed, department, status, news2Score, news2RiskLevel, qsofaScore, sepsisActive, sepsisBundleStatus, openAlertCount, sofaScore, sofaDelta, gcsScore, gcsClassification, lastObservationAt, attendingPhysician, admittedAt

Encounter status machine:

scheduled → active → discharged
          → cancelled

PATCH /encounters/{id}/status returns 409 on illegal transitions.

POST body:

Field	Type	Required	Description
encounterType	string	yes	INPATIENT, OUTPATIENT, EMERGENCY
department	string	yes
attendingPhysician	string	yes
roomBed	string	no	Ward and bed assignment (e.g. ICU-1A)
admissionReason	string	no	Clinical reason for admission

PATCH /encounters/{id}/status body — optional dischargeDiagnosis when transitioning to DISCHARGED.

Alert Thresholds

Method	Path	Description
POST	/alert-thresholds	Create a threshold
GET	/alert-thresholds	List all thresholds (paginated)
GET	/alert-thresholds/{id}	Get a threshold by ID
PUT	/alert-thresholds/{id}	Update a threshold; invalidates Redis cache
DELETE	/alert-thresholds/{id}	Delete a threshold; invalidates Redis cache; audit logged

Body:

Field	Type	Required	Description
observationCode	string	yes	e.g. HEART_RATE, SYSTOLIC_BP, AVPU, GLUCOSE_MG_DL
displayName	string	yes	Human-readable label
unit	string	yes	e.g. bpm, °C, mEq/L
criticalLow	decimal	no
warningLow	decimal	no
warningHigh	decimal	no
criticalHigh	decimal	no

Seeded thresholds (12 codes):

Code	Display	Unit	Critical Low	Warning Low	Warning High	Critical High
HEART_RATE	Heart Rate	bpm	30	50	100	150
TEMP_C	Temperature	°C	35.0	36.0	38.3	40.0
POTASSIUM_MEQ_L	Serum Potassium	mEq/L	2.5	3.5	5.0	6.5
SPO2	Oxygen Saturation	%	88	92	—	—
RESP_RATE	Respiratory Rate	breaths/min	—	12	20	30
WBC_K_UL	White Blood Cell Count	k/µL	2.0	4.0	12.0	20.0
SYSTOLIC_BP	Systolic Blood Pressure	mmHg	70	90	160	180
DIASTOLIC_BP	Diastolic Blood Pressure	mmHg	40	60	90	110
LACTATE_MMOL_L	Serum Lactate	mmol/L	—	—	2.0	4.0
AVPU	AVPU Consciousness	score	—	—	—	2
SUPPLEMENTAL_O2	Supplemental Oxygen	flag	—	—	—	—
GLUCOSE_MG_DL	Blood Glucose	mg/dL	40	70	180	400

Observations

Method	Path	Description
POST	/encounters/{id}/observations	Ingest one or more observations (max 10 per call)
GET	/encounters/{id}/observations	Cursor-paginated observation history

POST body:

Field	Type	Required	Description
observations	array	yes	One to ten observation objects

Observation object:

Field	Type	Required	Description
observationCode	string	yes	Must match a configured alert threshold
value	decimal	yes	Numeric measurement
unit	string	yes	Unit of measure
source	string	no	DEVICE (default), MANUAL, LAB
recordedAt	DateTimeOffset	yes	When the measurement was taken

Idempotency: Pass an Idempotency-Key header. Same key → original 201 response, no duplicate row.

Ingest transaction sequence:

1. Validate encounter is active
2. Check idempotency key
3. Validate observation value within plausible range
4. Insert observation row
5. Load alert threshold from Redis cache (→ PostgreSQL on miss)
6. If value breaches CRITICAL threshold: insert clinical_alert + outbox_event (topic: alert.generated)
7. Insert outbox_event (topic: observation.recorded)
8. COMMIT

Status codes:

Code	Meaning
201	Observation(s) recorded
200	Idempotency-Key matched existing observation
404	Encounter not found
409	Encounter is not active (discharged or cancelled)
422	Value outside plausible range or body invalid

GET query params:

Param	Description
code	Filter by observation code
from	Inclusive start (DateTimeOffset)
to	Inclusive end (DateTimeOffset)
limit	Page size (default 20)
cursor	Opaque cursor from previous response for next page

Uses cursor pagination on (recorded_at DESC, id DESC) — offset pagination would shift results as new observations arrive in a continuously growing table.

Clinical Alerts

Method	Path	Description
GET	/encounters/{id}/alerts	Paginated alert list for an encounter
GET	/alerts	Global alert list; optional status, severity, department filter
GET	/alerts/{id}	Alert detail
POST	/alerts/{id}/acknowledge	Acknowledge with clinician ID and optional note
POST	/alerts/{id}/resolve	Resolve (must be acknowledged first)

Alert lifecycle:

open → acknowledged → resolved
     → escalated (RabbitMQ DLQ after 5 min unacknowledged)

POST /alerts/{id}/acknowledge body:

Field	Type	Required	Description
clinicianId	string	yes	Clinician identifier
note	string	no	Optional acknowledgment note

Orders

Method	Path	Description
POST	/encounters/{id}/orders	Create a clinical order for an active encounter
GET	/encounters/{id}/orders	List orders for an encounter; optional status, page, pageSize
GET	/orders/{id}	Order detail with encounter
PATCH	/orders/{id}/status	Transition order status
PATCH	/orders/{id}/result	Record a result; transitions to Resulted

Order status machine:

pending → in_progress → resulted
        → cancelled

PATCH /orders/{id}/status and PATCH /orders/{id}/result return 409 on illegal transitions (e.g. cancelling a resulted order).

POST body:

Field	Type	Required	Description
orderType	string	yes	Lab, Imaging, Medication, Procedure
description	string	yes	Order description
orderedBy	string	yes	Ordering clinician

PATCH /orders/{id}/result body:

Field	Type	Required	Description
resultSummary	string	no	Free-text result summary

Analytics (Elasticsearch)

Method	Path	Description
GET	/analytics/patients	Patient/encounter search across MRN, name, department
GET	/analytics/observations/trend	Time-series aggregation (hourly avg/min/max) for a specific observation code per encounter
GET	/analytics/alerts/summary	Alert volume by department and severity over a time window
GET	/analytics/population	Count of patients with a value above or below a threshold in a time window

GET /analytics/patients query params: q (free text), department, status

GET /analytics/observations/trend query params: encounterId (required), code (required), from, to

GET /analytics/alerts/summary query params: severity, from, to, department

GET /analytics/population query params: code (required), threshold (required), from, to

The population query uses Elasticsearch's numeric range aggregation engine — no full-text search. Running this against PostgreSQL on the operational database would compete with ingest writes under load.

NEWS2 (National Early Warning Score 2)

Method	Path	Description
GET	/encounters/{id}/news2/current	Latest NEWS2 score for an encounter (404 if none computed)
GET	/encounters/{id}/news2/history	Cursor-paginated score history

GET /news2/current response includes totalScore, riskLevel (LOW, LOW_MEDIUM, MEDIUM, HIGH), all seven component scores (respRateScore, spo2Score, …), hasSingleParamThree, and calculatedAt.

GET /news2/history query params: limit (default 20), cursor (opaque token from previous response).

Scores are computed asynchronously by News2ScoringService after observations are ingested — allow a few seconds for the Kafka consumer to process all seven parameters before querying.

GCS (Glasgow Coma Scale)

Method	Path	Description
GET	/encounters/{id}/gcs	Latest GCS score for an encounter (null data if none computed)
GET	/encounters/{id}/gcs/history	Cursor-paginated GCS score history

GET /gcs response includes eyeScore, verbalScore, motorScore, totalScore (3–15), classification (MILD, MODERATE, SEVERE), and calculatedAt.

GET /gcs/history query params: limit (default 20), cursor (opaque token from previous response).

All three components (GCS_EYE, GCS_VERBAL, GCS_MOTOR) must be recorded before a score is computed. Scores are asynchronous via GcsScoringService. A completed GCS score publishes gcs.scored to Kafka (via outbox) for SOFA CNS re-scoring.

SOFA (Sequential Organ Failure Assessment)

Method	Path	Description
GET	/encounters/{id}/sofa	Latest SOFA score for an encounter (404 if none computed)
GET	/encounters/{id}/sofa/history	Cursor-paginated score history

Response includes totalScore, six component scores (respiratoryScore … renalScore), isBaseline, deltaFromBaseline, optional staleness metadata, and calculatedAt.

SOFA scores are computed asynchronously by SofaScoringService from SOFA-related observation codes (PAO2_MMHG, FIO2_PCT, PLATELET_K_UL, BILIRUBIN_MG_DL, CREATININE_MG_DL, URINE_OUTPUT_ML_H, vitals, SPO2, vasopressors) and from gcs.scored events (CNS organ system). Baseline is established when ≥ 4 of 6 organ systems have available data. Delta ≥ 2 from baseline creates a SOFA_SEPSIS alert; delta = 1 creates SOFA_WARNING. Poll /sofa/history to confirm baseline — the latest score may have isBaseline: false after subsequent observations.

Sepsis Bundles

Method	Path	Description
GET	/sepsis-bundles	Paginated list of bundles hospital-wide; optional status filter (IN_PROGRESS, COMPLIANT, NON_COMPLIANT); returns SepsisBundleSummary with patient demographics, elements, and deadlines
GET	/encounters/{id}/sepsis-bundle/current	Current (most recent) sepsis bundle for an encounter (404 if none)
GET	/sepsis-bundles/{id}	Bundle detail with all elements and linked orders

GET /sepsis-bundle/current response includes encounterId, triggeringAlertId, triggeringAlertType (SOFA_SEPSIS), recognizedAt, deadlineAt, complianceStatus (IN_PROGRESS, COMPLIANT, NON_COMPLIANT), completedAt, and elements[] — each with elementType, status, orderId, and completedAt.

Bundles are created automatically by SepsisAlertHandler when a SOFA_SEPSIS alert fires (delta ≥ 2 from baseline). Four clinical orders (blood cultures, serum lactate, broad-spectrum antibiotics, IV fluid resuscitation) are auto-created with orderedBy: sepsis-bundle-engine. As orders are resulted via PATCH /orders/{id}/result, the corresponding bundle element is marked complete. When all four elements are done, the bundle transitions to COMPLIANT (within the 1-hour deadline) or NON_COMPLIANT.

Medications

Method	Path	Description
POST	/encounters/{id}/medications	Record a medication administration for an active encounter
GET	/encounters/{id}/medications	List administrations; optional since ISO 8601 filter; paginated
GET	/medications/{id}	Medication administration detail

POST body:

Field	Type	Required	Description
drugName	string	yes	Drug name (case-insensitive for correlation lookups)
dose	decimal	yes	Must be > 0
doseUnit	string	yes	e.g. mg, g, mcg
route	string	yes	e.g. PO, IV
administeredAt	DateTimeOffset	no	Defaults to server time if omitted
administeredBy	string	yes	Clinician or nurse identifier

When a correlated drug was given within the MedicationCorrelation.CorrelationWindowMinutes window (default 90), subsequent warning and NEWS2 alerts for affected vitals include an annotation in details — e.g. — note: metoprolol 25mg (PO) administered 45 min ago. See docs/decisions/medication-correlation-design.md.

Sites

Method	Path	Auth	Description
POST	/sites	JWT + users:admin	Create a clinical site
GET	/sites	JWT + users:admin	List all sites
GET	/sites/{siteId}	JWT + users:admin	Site detail

POST body:

Field	Type	Required	Description
siteCode	string	yes	Uppercase alphanumeric with hyphens (max 32)
name	string	yes	Hospital/site name (max 200)
address	string	no	Site address (max 500)

Gateways

Method	Path	Auth	Description
POST	/sites/{siteId}/gateways	JWT + users:admin	Register a gateway under a site
GET	/sites/{siteId}/gateways	JWT + users:admin	List gateways; optional ?department= filter
GET	/gateways/{gatewayId}	JWT + users:admin	Gateway detail
PATCH	/gateways/{gatewayId}/heartbeat	Gateway API key	Update status and buffer depth

POST /sites/{siteId}/gateways body:

Field	Type	Required	Description
gatewayCode	string	yes	Unique per site (max 64)
department	string	yes	Department assignment (max 100)

PATCH /gateways/{gatewayId}/heartbeat body:

Field	Type	Required	Description
status	string	yes	ONLINE, DEGRADED, or OFFLINE
bufferDepth	int	yes	Unsynced event count (≥ 0)
reportedAtUtc	DateTimeOffset	yes	Gateway-reported timestamp

Gateway API key auth: Set X-Api-Key header (configured in ApiKey:Gateway) and X-Gateway-Id header. The handler validates the key with constant-time comparison and confirms the gateway ID in the URL matches the header.

Authentication

Method	Path	Description
POST	/auth/login	Authenticate with username/password; returns JWT bearer token
GET	/auth/me	Returns the authenticated user's profile (user ID, username, display name, role)

POST /auth/login body:

Field	Type	Required	Description
username	string	yes	Username
password	string	yes	Password

Response:

Field	Type	Description
accessToken	string	JWT bearer token
expiresAt	DateTimeOffset	Token expiration (default 8 hours)
userId	Guid	User ID
username	string	Username
displayName	string	Display name
role	string	NURSE, PHYSICIAN, ADMIN, INTEGRATION

Seeded demo users:

Username	Password	Role
nurse.demo	DemoNurse1!	Nurse
physician.demo	DemoPhysician1!	Physician
admin.demo	DemoAdmin1!	Admin
integration.mirth	MirthIntegration1!	Integration

RBAC permission matrix:

Permission	Nurse	Physician	Admin	Integration
patients:read	yes	yes	yes	—
patients:write	yes	yes	yes	yes
encounters:read	yes	yes	yes	—
encounters:write	yes	yes	yes	yes
observations:ingest	yes	yes	yes	yes
alerts:read	yes	yes	yes	—
alerts:acknowledge	yes	yes	yes	—
alerts:resolve	yes	yes	yes	—
thresholds:read	yes	yes	yes	—
thresholds:write	—	—	yes	—
analytics:read	yes	yes	yes	—
orders:write	yes	yes	yes	—
medications:write	yes	yes	yes	yes
fhir:ingest	—	—	yes	yes
fhir:read	—	—	yes	yes
audit:read	—	—	yes	—
users:admin	—	—	yes	—

All endpoints except POST /auth/login and GET /fhir/R4/metadata require authentication. Unauthenticated requests receive 401. Authenticated requests without the required permission receive 403.

Audit Logs

Method	Path	Description
GET	/audit-logs	Query clinical audit logs (Admin only — requires audit:read permission)

GET /audit-logs query params: entityType, entityId, userId, action, from, to, page, pageSize

Audit actions: THRESHOLD_CREATED, THRESHOLD_UPDATED, THRESHOLD_DELETED, ALERT_ACKNOWLEDGED, ALERT_RESOLVED, ENCOUNTER_STATUS_CHANGED, PATIENT_REGISTERED, SUPPRESSION_WINDOW_SET, USER_LOGIN, AUTHORIZATION_DENIED

Each audit log entry includes action, entityType, entityId, userId, userDisplayName, previousValueJson (JSONB), newValueJson (JSONB), reason, ipAddress, correlationId, and createdAt.

FHIR R4 Ingest

All FHIR endpoints are under /fhir/R4, accept application/fhir+json, and return FHIR R4 JSON responses. Authentication is via JWT bearer token or X-Api-Key header (configured in Fhir:ApiKey or the Fhir:ApiKeys array for zero-downtime key rotation; disabled when blank). API key validation uses CryptographicOperations.FixedTimeEquals to prevent timing attacks. When a valid JWT is present, the API key check is skipped — this allows both integration engines (API key) and authenticated admin users (JWT) to access FHIR resources. Write endpoints (POST) require fhir:ingest permission; read endpoints (GET) require fhir:read permission. Errors return a FHIR OperationOutcome with appropriate issue codes.

Method	Path	Description
GET	/fhir/R4/metadata	CapabilityStatement — supported resource types and interactions
POST	/fhir/R4/Patient	Upsert a Patient by hospital identifier (MRN); idempotent
GET	/fhir/R4/Patient/{id}	Read a Patient by internal ID; returns FHIR R4 Patient resource
GET	/fhir/R4/Patient	Search Patients by identifier (system|value) or list all; returns Bundle (searchset)
POST	/fhir/R4/Encounter	Upsert an Encounter by visit identifier; resolves patient by identifier
GET	/fhir/R4/Encounter/{id}	Read an Encounter by internal ID; returns FHIR R4 Encounter resource
GET	/fhir/R4/Encounter	Search Encounters by patient (UUID), status (in-progress/finished/cancelled); returns Bundle (searchset)
POST	/fhir/R4/Observation	Ingest an Observation; maps LOINC/SNOMED codes to internal codes; supports component observations
POST	/fhir/R4/MedicationAdministration	Record a medication administration; resolves encounter by identifier
POST	/fhir/R4	Process a transaction Bundle (Patient → Encounter → Observation/MedicationAdministration in dependency order)

CapabilityStatement: GET /fhir/R4/metadata advertises create, read, and searchType interactions for Patient and Encounter; create only for Observation and MedicationAdministration; and Bundle transaction support.

Identifier resolution: FHIR resources reference each other by hospital identifiers (e.g. MRN in Patient.identifier, visit number in Encounter.identifier). The ExternalResourceIdentifier table maps these to internal UUIDs. On first ingest, a new internal record is created and the identifier is linked. Subsequent requests with the same identifier update the existing record (idempotent upsert).

LOINC code mapping: 19 LOINC codes and 3 SNOMED CT fallback codes map to internal observation codes (see LoincCodeMapper). Unsupported codes return 422 with an OperationOutcome. Temperature observations in Fahrenheit ([degF]) are automatically converted to Celsius.

Transaction Bundles: POST /fhir/R4 accepts Bundle.type=transaction. Entries are processed in dependency order (Patient first, then Encounter, then Observation/MedicationAdministration). On first failure, processing stops (transaction semantics) and the response includes the OperationOutcome.

Read interactions: GET /fhir/R4/Patient/{id} and GET /fhir/R4/Encounter/{id} return the internal resource mapped back to a FHIR R4 resource with hospital identifiers resolved from ExternalResourceIdentifier. Returns 404 with an OperationOutcome if the resource is not found.

Search interactions: GET /fhir/R4/Patient?identifier=system|value searches by external identifier; omitting identifier lists all patients (up to _count, default 20). GET /fhir/R4/Encounter?patient={uuid}&status=in-progress filters encounters by patient and/or FHIR status (in-progress, finished, cancelled). Both return a Bundle with type=searchset.

Integration with Mirth Connect: HL7v2 ADT messages (A01 admit, A03 discharge, A08 update) and ORU R01 lab results can be mapped to FHIR Bundles via Mirth channels. See docs/integration/mirth-fhir-channels.md.

---

Data Models

Patient

id                    Guid    PK
mrn                   string  required, unique — auto-generated on registration (e.g. MRN-000001)
firstName             string  required (max 100)
lastName              string  required (max 100)
dateOfBirth           Date    required
gender                string  required (max 10)
bloodType             string? A+ | A- | B+ | B- | AB+ | AB- | O+ | O-
allergies             string? free text
emergencyContactName  string? (max 200)
emergencyContactPhone string? (max 30)
status                string  active | inactive  (default: active)
createdAt             DateTimeOffset

Encounter

id                  Guid    PK
patientId           Guid    FK → Patient
encounterType       string  INPATIENT | OUTPATIENT | EMERGENCY
status              string  scheduled | active | discharged | cancelled  (default: scheduled)
department          string  required (max 100)
attendingPhysician  string  required (max 200)
roomBed             string? ward/bed assignment (max 50)
admissionReason     string? clinical reason for admission
dischargeDiagnosis  string? set on discharge
admittedAt          DateTimeOffset
dischargedAt        DateTimeOffset?
createdAt           DateTimeOffset

Indexes: (patient_id, admitted_at DESC), partial (status, admitted_at DESC) WHERE status = 'active', partial unique (patient_id, encounter_type) WHERE status = 'ACTIVE' (prevents duplicate active encounters of the same type per patient)

AlertThreshold

id               Guid    PK
observationCode  string  required, unique (max 50)
displayName      string  required (max 200)
unit             string  required (max 20)
criticalLow      decimal(10,3)?
warningLow       decimal(10,3)?
warningHigh      decimal(10,3)?
criticalHigh     decimal(10,3)?
createdAt        DateTimeOffset

Observation

id               Guid    PK
encounterId      UUID    FK → Encounter
observationCode  string  required (max 50)
value            decimal(10,3) required
unit             string  required (max 20)
source           string  DEVICE | MANUAL | LAB  (default: DEVICE)
idempotencyKey   string? optional, partial unique index
recordedAt       DateTimeOffset required
createdAt        DateTimeOffset

Indexes: partial unique (idempotency_key) WHERE idempotency_key IS NOT NULL, (encounter_id, observation_code, recorded_at DESC)

ClinicalAlert

id              Guid    PK
encounterId     Guid    FK → Encounter
patientId       Guid    FK → Patient
observationId   Guid?   FK → Observation (null for NEWS2, GCS, SOFA composite alerts)
alertType       string  e.g. CRITICAL_HEART_RATE, QSOFA_SCREEN, SOFA_SEPSIS, NEWS2_WARNING, NEWS2_EMERGENCY, GCS_CRITICAL
severity        string  WARNING | CRITICAL
details         text    required
observationCode string? observation code that triggered this alert (e.g. HEART_RATE) — enables direct lookups without LIKE pattern matching
status          string  open | acknowledged | resolved | escalated  (default: open)
acknowledgedAt  DateTimeOffset?
acknowledgedBy  string?
resolvedAt      DateTimeOffset?
triggeredAt     DateTimeOffset

Indexes: (encounter_id, triggered_at DESC), (patient_id, triggered_at DESC), partial (severity, triggered_at DESC) WHERE status = 'open', (encounter_id, observation_code, status)

News2Score

id                    Guid    PK
encounterId           Guid    FK → Encounter
patientId             Guid    FK → Patient
totalScore            int     aggregate 0–20+
riskLevel             string  LOW | LOW_MEDIUM | MEDIUM | HIGH
respRateScore         int     component 0–3
spo2Score             int
systolicBpScore       int
heartRateScore        int
consciousnessScore    int
temperatureScore      int
supplementalO2Score   int
hasSingleParamThree   bool    true when any single parameter scored 3
calculatedAt          DateTimeOffset

Indexes: (encounter_id, calculated_at DESC), (patient_id, calculated_at DESC)

GcsScore

id              Guid    PK
encounterId     Guid    FK → Encounter
patientId       Guid    FK → Patient
eyeScore        int     1–4
verbalScore     int     1–5
motorScore      int     1–6
totalScore      int     3–15
classification  string  MILD | MODERATE | SEVERE
calculatedAt    DateTimeOffset

Indexes: (encounter_id, calculated_at DESC)

SofaScore

id                  Guid    PK
encounterId         Guid    FK → Encounter
patientId           Guid    FK → Patient
totalScore          int     sum of six components (0–24)
respiratoryScore    int     0–4
coagulationScore    int     0–4
liverScore          int     0–4
cardiovascularScore int     0–4
cnsScore            int     0–4
renalScore          int     0–4
isBaseline          bool    true for admission baseline row
deltaFromBaseline   int?    current total minus baseline total
stalenessFlags      jsonb?  stale/missing components, SpO2 fallback flag
calculatedAt        DateTimeOffset

Indexes: (encounter_id, calculated_at DESC), partial (encounter_id) WHERE is_baseline = true

QsofaEvaluation

id                Guid    PK
encounterId       Guid    FK → Encounter
patientId         Guid    FK → Patient (via Encounter)
activeCriteria    int     0–3 (check constraint)
respRate          decimal? respiratory rate value at evaluation time
systolicBp        decimal? systolic BP value at evaluation time
avpu              decimal? AVPU/GCS value at evaluation time
screenAlertFired  bool    true if this evaluation triggered a QSOFA_SCREEN alert
evaluatedAt       DateTimeOffset
createdAt         DateTimeOffset

Indexes: (encounter_id, evaluated_at)

Order

id            Guid    PK
encounterId   Guid    FK → Encounter
orderType     string  LAB | MEDICATION | IMAGING
description   string  required (max 500)
orderedBy     string  required (max 200)
status        string  pending | in_progress | resulted | cancelled  (default: pending)
orderedAt     DateTimeOffset
resultedAt    DateTimeOffset?
resultSummary string? Free-text result summary (set on record result)

Indexes: (encounter_id, ordered_at DESC), partial (status, ordered_at) WHERE status IN ('pending', 'in_progress')

SepsisBundle

id                    Guid    PK
encounterId           Guid    FK → Encounter
triggeringAlertId     Guid    FK → ClinicalAlert
triggeringAlertType   string  required (max 50) — SOFA_SEPSIS
recognizedAt          DateTimeOffset
deadlineAt            DateTimeOffset — recognizedAt + 1 hour
complianceStatus      string  IN_PROGRESS | COMPLIANT | NON_COMPLIANT  (default: IN_PROGRESS)
completedAt           DateTimeOffset?

Indexes: (encounter_id, recognized_at DESC), (compliance_status), (triggering_alert_id), partial unique (encounter_id) WHERE compliance_status = 'IN_PROGRESS' (prevents TOCTOU race on concurrent bundle creation)

Check constraint: compliance_status IN ('IN_PROGRESS', 'COMPLIANT', 'NON_COMPLIANT')

SepsisBundleElement

id            Guid    PK
bundleId      Guid    FK → SepsisBundle (CASCADE)
elementType   string  required (max 40) — BLOOD_CULTURES | SERUM_LACTATE | BROAD_SPECTRUM_ANTIBIOTICS | IV_FLUID_RESUSCITATION
status        string  PENDING | COMPLETED  (default: PENDING)
orderId       Guid?   FK → Order (SET NULL)
completedAt   DateTimeOffset?

Indexes: unique (bundle_id, element_type), (order_id)

Check constraints: element_type IN (...), status IN ('PENDING', 'COMPLETED')

MedicationAdministration

id              Guid    PK
encounterId     Guid    FK → Encounter (Restrict on delete)
drugName        string  required (max 200)
dose            decimal(10,4) required
doseUnit        string  required (max 20)
route           string  required (max 20)
administeredAt  DateTimeOffset required
administeredBy  string  required (max 200)

Indexes: (encounter_id, administered_at), (encounter_id, drug_name)

OutboxEvent

id           Guid    PK
topic        string  required (max 200)
partitionKey string? — encounterId for per-encounter ordering
payload      JSONB   required
createdAt    DateTimeOffset
processedAt  DateTimeOffset?
retryCount   int     default 0 — Kafka produce attempt counter
lastError    string? — last Kafka produce failure reason
failedAt     DateTimeOffset? — set when retryCount exceeds OutboxMaxRetries (permanently failed)

Partial index: (created_at) WHERE processed_at IS NULL AND failed_at IS NULL

ExternalResourceIdentifier

id              Guid    PK
resourceType    string  PATIENT | ENCOUNTER
internalId      Guid    FK → Patient or Encounter (logical, not enforced)
system          string  required — identifier system URI (e.g. http://hospital.example/mrn)
value           string  required — identifier value (e.g. MRN-001)
createdAt       DateTimeOffset

Unique index: (resource_type, system, value) — one mapping per external identifier

ClinicalUser

id              Guid    PK
username        string  required, unique (max 100)
passwordHash    string  required (BCrypt)
displayName     string  required (max 200)
role            string  NURSE | PHYSICIAN | ADMIN | INTEGRATION
isActive        bool    default true
createdAt       DateTimeOffset
lastLoginAt     DateTimeOffset?

ClinicalAuditLog

id                Guid    PK
action            string  required (max 50) — THRESHOLD_CREATED | THRESHOLD_UPDATED | THRESHOLD_DELETED | ALERT_ACKNOWLEDGED | ALERT_RESOLVED | ENCOUNTER_STATUS_CHANGED | PATIENT_REGISTERED | SUPPRESSION_WINDOW_SET | USER_LOGIN | AUTHORIZATION_DENIED
entityType        string  required (max 100) — e.g. AlertThreshold, ClinicalAlert, Encounter, Patient, ClinicalUser
entityId          Guid    required
userId            Guid?   FK → ClinicalUser (null for system-initiated actions)
userDisplayName   string? (max 200)
previousValueJson jsonb?  state before the action
newValueJson      jsonb?  state after the action
reason            string? optional clinician-provided reason
ipAddress         string? (max 45) — IPv4 or IPv6
correlationId     string? (max 100) — links to request correlation header
createdAt         DateTimeOffset

Append-only — no UPDATE or DELETE from application code.

Indexes: (entity_type), (entity_id), (user_id), (created_at)

ClinicalSite

id          Guid    PK
siteCode    string  required, unique (max 32) — uppercase alphanumeric with hyphens
name        string  required (max 200)
address     string? free text
active      bool    default true
createdAt   DateTimeOffset

Indexes: unique (site_code)

WardGateway

id                    Guid    PK
siteId                Guid    FK → ClinicalSite (RESTRICT)
gatewayCode           string  required (max 64)
department            string  required (max 100)
status                string  ONLINE | DEGRADED | OFFLINE  (default: OFFLINE)
reportedBufferDepth   int     default 0
lastHeartbeatAt       DateTimeOffset?
lastSyncAt            DateTimeOffset?
createdAt             DateTimeOffset

Indexes: unique (site_id, gateway_code), (site_id, department), partial (status) WHERE status != 'ONLINE'

Check constraint: status IN ('ONLINE', 'DEGRADED', 'OFFLINE')

ReconciliationAlert

id            Guid    PK
checkType     string  UNACKNOWLEDGED_CRITICAL_ALERT | PENDING_ORDER_NO_RESULT | ACTIVE_INPATIENT_NO_OBSERVATION
encounterId   Guid?   FK → Encounter
patientId     Guid?   FK → Patient
details       text    required
resolvedAt    DateTimeOffset?
createdAt     DateTimeOffset

---

Elasticsearch Index Shapes

patient_encounters

{
  "encounterId": "uuid",
  "patientId": "uuid",
  "mrn": "MRN-000001",
  "patientName": "Jane Smith",
  "department": "ICU",
  "status": "active",
  "attendingPhysician": "Dr. Osei",
  "roomBed": "ICU-4B",
  "admissionReason": "Chest pain, rule out MI",
  "admittedAt": "2025-01-01T08:00:00Z",
  "openAlertCount": 2,
  "news2Score": 6,
  "news2RiskLevel": "MEDIUM",
  "sepsisBundleStatus": "IN_PROGRESS",
  "sepsisBundleElementsCompleted": 2,
  "sepsisBundleDeadlineAt": "2025-01-01T09:00:00Z",
  "lastObservationAt": "2025-01-01T09:45:00Z"
}

news2Score and news2RiskLevel are optional — populated by EsIndexerService when a NEWS2_WARNING or NEWS2_EMERGENCY alert is indexed (payload fields news2Score / news2RiskLevel from News2Detector). LOW-risk scores with no alert are not projected to Elasticsearch.

sepsisBundleStatus, sepsisBundleElementsCompleted, and sepsisBundleDeadlineAt are optional — populated by EsIndexerService from sepsis.bundle.created and sepsis.bundle.updated Kafka events. Enables department dashboards to filter/sort encounters by sepsis bundle compliance in real time.

observations

{
  "observationId": "uuid",
  "encounterId": "uuid",
  "patientId": "uuid",
  "mrn": "MRN-000001",
  "observationCode": "HEART_RATE",
  "value": 118.0,
  "unit": "bpm",
  "source": "DEVICE",
  "recordedAt": "2025-01-01T09:45:00Z"
}

clinical_alerts

{
  "alertId": "uuid",
  "encounterId": "uuid",
  "patientId": "uuid",
  "department": "ICU",
  "alertType": "THRESHOLD_BREACH",
  "severity": "CRITICAL",
  "status": "open",
  "triggeredAt": "2025-01-01T09:45:00Z"
}

---

RabbitMQ Exchange Topology

Exchange: clinical.notifications.exchange (direct)

Queue	Purpose	DLQ
alerts.paging.queue	Physician paging jobs; prefetch=3	→ alerts.paging.dlq on NACK
alerts.paging.dlq	Dead-letter queue; x-message-ttl = 300000ms	→ alerts.escalation.queue on TTL expiry
alerts.escalation.queue	On-call backup paging	—
notifications.discharge.queue	Discharge summary PDF generation + MinIO upload	—
notifications.reconciliation.queue	Reconciliation safety findings from scheduled checks	—
notifications.appointment.queue	Appointment reminder SMS	—

---

Kafka Topics

Topic	Partition key	Consumer groups
observation.recorded	encounterId	es-indexer, sepsis-engine (qSOFA), warning-evaluator, news2-scoring, gcs-scoring, sofa-scoring, trend-analyzer, data-lake-writer
alert.generated	encounterId	es-indexer, notification-publisher, data-lake-writer
encounter.status.changed	encounterId	es-indexer, data-lake-writer
gcs.scored	encounterId	sofa-scoring
sepsis.bundle.created	encounterId	es-indexer
sepsis.bundle.updated	encounterId	es-indexer

All topics use 6 partitions. KAFKA_AUTO_CREATE_TOPICS_ENABLE=false — topics (including gcs.scored) are provisioned explicitly by KafkaTopicProvisioner on API startup.

alert.generated payload (minimum fields for downstream consumers):

Field	Required by	Notes
alertId, encounterId, patientId	ES indexer, data lake, paging	UUIDs
alertType, severity, triggeredAt	All consumers	DB string literals for type/severity
details	Data lake Parquet	Human-readable breach summary; always set on new alerts
department	ES indexer	Optional; critical ingest alerts include it
news2Score, news2RiskLevel	ES indexer	Optional; set on NEWS2_WARNING / NEWS2_EMERGENCY alerts for encounter document projection
partitionKey	Outbox relay	Same as encounterId

---

---

qSOFA Screening (Sepsis-3 Bedside Tool)

The qSOFA (quick Sequential Organ Failure Assessment) engine evaluates three organ-dysfunction criteria per encounter within the SepsisEngineService Kafka consumer. Redis keys use a 30-minute TTL sliding window:

Criterion	Observation Code	Trigger
Tachypnea	RESP_RATE	≥ 22 breaths/min
Hypotension	SYSTOLIC_BP	≤ 100 mmHg
Altered mentation	GCS / AVPU	GCS < 15 or AVPU ≥ 1 (any non-Alert state)

Redis key pattern: qsofa:{encounterId}:{code} with 30-minute TTL. When a criterion normalizes, the key is deleted immediately. When ≥ 2 of 3 criteria are active simultaneously and no open QSOFA_SCREEN alert exists, the engine inserts a WARNING-level screening alert with details formatted as "qSOFA score 2/3: RESP_RATE=24, SYSTOLIC_BP=95 — recommend SOFA lab panel".

Clinical role: qSOFA is a bedside screening tool — it identifies patients who should have SOFA labs ordered. It does not trigger the sepsis bundle directly. Only SOFA_SEPSIS (delta ≥ 2 from baseline) triggers bundle creation. This matches the Sepsis-3 two-tier workflow: screen → confirm → treat.

API: GET /encounters/{id}/qsofa/current returns activeCriteria (0–3) and per-criterion values from Redis via QsofaService — used by ward dashboards and the simulator poll loop. GET /encounters/{id}/qsofa/history returns cursor-paginated evaluation history from the qsofa_evaluations table, including criteria values and whether a screen alert was fired — used by the QsofaHistory.vue dashboard chart.

---

Sepsis Bundle Compliance (SEP-1)

When a SOFA_SEPSIS alert fires (delta ≥ 2 from baseline), SepsisAlertHandler calls SepsisBundleService.TryCreateBundleAsync() to initiate a four-element treatment bundle with a one-hour compliance deadline:

Bundle Element	Order Type	Auto-Created Order Description
BLOOD_CULTURES	Lab	SEP-1: Blood cultures
SERUM_LACTATE	Lab	SEP-1: Serum lactate
BROAD_SPECTRUM_ANTIBIOTICS	Medication	SEP-1: Broad-spectrum antibiotics
IV_FLUID_RESUSCITATION	Procedure	SEP-1: IV fluid bolus

Lifecycle:

1. SOFA_SEPSIS alert fires → SepsisAlertHandler → SepsisBundleService.TryCreateBundleAsync()
2. Bundle created with complianceStatus = IN_PROGRESS, deadlineAt = recognizedAt + 1 hour
3. Four orders created (orderedBy: sepsis-bundle-engine), each linked to a bundle element
4. Outbox event → Kafka topic sepsis.bundle.created → ES indexer projects sepsisBundleStatus on encounter
5. Clinicians work through orders; PATCH /orders/{id}/result → OrderService → SepsisBundleService.OnOrderResultedAsync()
6. Each resulted order marks its bundle element COMPLETED; outbox event → sepsis.bundle.updated → ES update
7. When all four elements are complete: complianceStatus = COMPLIANT (within deadline) or NON_COMPLIANT (past deadline); Prometheus sepsis_bundle_compliance_total{status} incremented
8. If the deadline passes with incomplete elements, SepsisBundleMonitorService (polling every 5 min) marks the bundle NON_COMPLIANT — elements remain PENDING but the bundle status reflects the missed deadline

Idempotency: Only one in-progress bundle can exist per encounter, enforced by a partial unique index (encounter_id) WHERE compliance_status = 'IN_PROGRESS'. Bundle creation wraps order and bundle inserts in a single database transaction — if the unique constraint rejects a concurrent duplicate, the transaction rolls back all associated orders, preventing orphaned order records. A second alert for the same encounter returns early without side effects.

---

NEWS2 Scoring

The NEWS2 engine evaluates seven observation codes that overlap with the expanded vital-sign vocabulary from Phase 10:

Parameter	Observation Code	Score range
Respiratory rate	RESP_RATE	0–3
Oxygen saturation (Scale 1)	SPO2	0–3
Systolic blood pressure	SYSTOLIC_BP	0–3
Heart rate	HEART_RATE	0–3
Consciousness (AVPU)	AVPU	0 or 3
Temperature	TEMP_C	0–3
Supplemental oxygen	SUPPLEMENTAL_O2	0 or 2

Risk levels (aggregate score):

Total score	Risk level	Alert
0–4 (no single param = 3)	LOW	None
Any single param = 3 (total under 5)	LOW_MEDIUM	NEWS2_WARNING
5–6	MEDIUM	NEWS2_WARNING
≥ 7	HIGH	NEWS2_EMERGENCY (CRITICAL)

All seven parameters must be present in Redis (4-hour TTL per key) before a score is computed. Each new observation after completeness triggers a new news2_scores row; alert creation is idempotent per encounter and alert type while an alert remains open.

---

Elasticsearch Index Replay

If the Elasticsearch indices need to be rebuilt (e.g., after a mapping change or data loss):

# 1. Stop the indexer consumer group (set consumer group to a known-good offset, or reset to beginning)
# 2. Delete existing indices
curl -X DELETE http://localhost:9200/patient_encounters
curl -X DELETE http://localhost:9200/observations
curl -X DELETE http://localhost:9200/clinical_alerts

# 3. Reset the es-indexer consumer group offset to the beginning
docker exec -it <kafka-container> kafka-consumer-groups.sh \
  --bootstrap-server localhost:9092 \
  --group es-indexer \
  --topic observation.recorded \
  --reset-offsets --to-earliest --execute

# 4. Restart the application — EsIndexerService will replay all events from offset 0
dotnet run

The indices rebuild from the full Kafka history. Document count should match PostgreSQL row count when complete. This is only possible because Kafka retains events after consumption.

---

Data Lake Replay

The MinIO Parquet archive is a pure Kafka projection — rebuildable without touching PostgreSQL. See docs/plans/phase-9-plan.md for the full procedure. Summary:

# Reset data-lake-writer offsets to earliest
docker compose exec -T kafka /opt/kafka/bin/kafka-consumer-groups.sh \
  --bootstrap-server localhost:9092 \
  --group data-lake-writer \
  --reset-offsets --to-earliest --all-topics --execute

# Clear Parquet prefixes in MinIO (mc alias localvc http://localhost:9005 minioadmin minioadmin)
mc rm --recursive --force localvc/vigilcare/observations/
mc rm --recursive --force localvc/vigilcare/alerts/
mc rm --recursive --force localvc/vigilcare/encounters/

# Restart the API — DataLakeWriterService replays from offset 0
dotnet run

Verify with ./scripts/run-phase9-verification.sh.

---

Pagination

List endpoints use offset pagination:

Param	Default	Description
page	1	Page number (1-based)
pageSize	20	Items per page (max 100)

Response shape:

{
  "items": [],
  "page": 1,
  "pageSize": 20,
  "totalCount": 42,
  "totalPages": 3
}

Observation history uses cursor pagination on (recorded_at DESC, id DESC). Offset pagination would shift results as new observations arrive continuously. The cursor is opaque and returned in the response; pass it as ?cursor= on the next request.

---

Implemented Phases

Twenty-nine phases from the project roadmap are implemented and verified, including the Site & Gateway Registry (Phase 20), the Ward Gateway Service (Phase 21), the Dashboard Gap Analysis Fixes (Phase 22), the Sepsis-3 clinical refactor (Phases 27–29), the FHIR R4 Inbound Facade (Phase 30), RBAC with clinical audit logging (Phase 31), and the Enhanced Dashboard (department overview, sepsis bundle board, critical alert notifications, shift handoff reports, vitals entry, sortable/filterable ward table). Integration tests (dotnet test) and per-phase verification scripts cover Phases 8–15, 20–22, 25–31. Phases 17–19 add the Vue dashboard and clinician feedback (Vitest in vigilcare-dashboard/).

Phase	Feature	Status
1	Schema, EF Core migrations, patient/encounter CRUD, alert threshold CRUD, encounter status machine, Redis threshold pre-load, seed data	Done
2	Observation ingest — idempotency, plausibility validation, synchronous critical alert creation, outbox event, cursor-paginated history; alert lifecycle (acknowledge, resolve); integration tests	Done
3	Outbox relay (IHostedService, 500ms poll); Kafka topics with 6 partitions; encounterId partition key; relay survives Kafka restart	Done
4	Elasticsearch CQRS projection (EsIndexerService); patient search; observation trend; alert summary; population aggregation; replay procedure	Done
5	Sepsis engine (SepsisEngineService); Redis-based qSOFA screening (SIRS removed in Phase 27); idempotent alert creation; integration tests	Done
6	RabbitMQ exchange and queue topology; NotificationPublisherService; PagingWorkerService; DLQ escalation (EscalationWorkerService); discharge summary (DischargeSummaryWorkerService → MinIO); integration tests	Done
7	Reconciliation scheduler — unacknowledged critical alerts, stale pending orders, disconnected monitors; reconciliation_alerts table; RabbitMQ publish; integration tests	Done
8	Prometheus metrics (GET /metrics); ten metric families and three collectors; Grafana clinical dashboard; ObservabilityPhase8Tests; run-phase8-verification.sh	Done
9	Data lake writer — data-lake-writer consumer group; date-partitioned Parquet flush to MinIO; DataLakePhase9Tests; run-phase9-verification.sh; design doc in docs/decisions/data-lake-design.md	Done
10	Clinical data model expansion — BloodType, patient allergies/emergency contact, encounter room/bed/admission/discharge fields; five new observation codes (SYSTOLIC_BP, DIASTOLIC_BP, LACTATE_MMOL_L, AVPU, SUPPLEMENTAL_O2); GLUCOSE_MG_DL threshold fix; 12 seeded thresholds; ClinicalDemographicsAndObservationTests; run-phase10-verification.sh	Done
11	Warning alert consumer (WarningAlertService / warning-evaluator); 10 Warning* alert types; Orders API (OrdersController, OrderService); FluentValidation on all request DTOs; WarningAlertTests, OrderLifecycleTests, ValidationTests; run-phase11-verification.sh	Done
12	NEWS2 composite scoring (News2Calculator, News2Detector, News2ScoringService); news2_scores table; NEWS2_WARNING / NEWS2_EMERGENCY alert types; News2Controller (current + history); ES news2Score / news2RiskLevel projection; Prometheus NEWS2 metrics; News2CalculatorTests, News2DetectorTests; run-phase12-verification.sh	Done
13	Trend detection (TrendCalculator, TrendDetector, TrendAnalyzerService); RAPID_DETERIORATION alert type; alert suppression windows (AlertSuppressionService, Redis suppress:{enc}:{type}); TrendCalculatorTests, TrendDetectorTests, AlertSuppressionTests; run-phase13-verification.sh	Done
14	qSOFA scoring engine (QsofaCalculator, QsofaDetector); sepsis bundle compliance (SepsisBundle, SepsisBundleElement, SepsisBundleService); auto-created treatment orders with 1-hour deadline; SepsisAlertHandler bridge; SepsisBundleMonitorService (5-min overdue scan); SepsisBundlesController API; ES projection of bundle status; Kafka topics sepsis.bundle.created / sepsis.bundle.updated; Prometheus qsofa_detections_total and sepsis_bundle_compliance_total; QsofaCalculatorTests, QsofaDetectorTests, SepsisBundleTests (bundle trigger updated to SOFA_SEPSIS in Phase 27)	Done
15	Medication administration (MedicationAdministration, MedicationsController, MedicationService); drug-vital correlation config (MedicationCorrelationOptions); MedicationCorrelationHelper annotates WarningEvaluator and News2Detector alert details; medication_administrations table + migration; MedicationServiceTests, MedicationCorrelationTests, MedicationValidationTests; run-phase15-verification.sh; design doc in docs/decisions/medication-correlation-design.md	Done
16	Console replay simulator (VigilCare.Simulator); scenario JSON schema; CLI commands replay, replay-all, validate, dry-run; speed multiplier and optional API polling; eight sample scenarios; docs/simulator-guide.md	Done
20	Site & Gateway Registry + Clinical Sync Contracts — VigilCare.ClinicalContracts shared class library with sync DTOs (ClinicalSyncBatchRequest, SyncedObservation, SyncedAlertEvent, GatewayHeartbeatRequest); ClinicalSite and WardGateway domain entities with EF Core configurations and migrations; GatewayApiKeyAuthenticationHandler (constant-time X-Api-Key validation + X-Gateway-Id claim) registered alongside JWT bearer; SitesController (create, list, get) and GatewaysController (register, list, get, heartbeat) with dual auth — JWT + users:admin for admin CRUD, gateway API key for heartbeat; SiteService, GatewayRegistryService; FluentValidation on CreateSiteRequest, RegisterGatewayRequest, GatewayHeartbeatRequest; GatewayRegistrySeeder with fixed GUIDs for demo site and gateway; WardGatewayMetricsCollector (60s periodic) exports ward_gateways_offline_gauge and ward_gateway_buffer_depth; GatewayRegistryTests (register, heartbeat, API key 401, degraded status, department filter); ClinicalContractsTests (JSON round-trip); run-phase20-verification.sh	Done
21	Ward Gateway Service (Local-First Clinical Path) — VigilCare.WardGateway standalone ASP.NET Core 8 deployable with its own PostgreSQL (vigilcare_ward), Redis, and RabbitMQ; domain entities mirror central API (ReplicaPatient, ReplicaEncounter, LocalObservation, LocalClinicalAlert, ReplicaAlertThreshold); LocalObservationService ingests observations locally with plausibility validation and synchronous critical alert creation; LocalWarningEvaluator creates warning-range alerts from Redis-cached thresholds; BufferedSyncWriter writes observation and alert events to buffered_sync_items table for upload when online; EncounterReplicaSyncService pulls patient/encounter data from central API on startup; ThresholdCacheLoader fetches alert thresholds from central API into local Redis; CentralReachabilityService polls central API health every 30s; GatewayHeartbeatService reports gateway status and buffer depth to central registry; SyncUploaderService batches buffered sync items and uploads to central API using ClinicalSyncBatchRequest contracts when online; local RabbitMQ paging (LocalPagingWorkerService) and escalation (LocalEscalationWorkerService) for ward-level clinician notification; EncounterReadService provides ward encounter list and detail views; Docker Compose ward-gateway profile with separate PostgreSQL, Redis, and RabbitMQ; health checks (Redis, RabbitMQ, encounter replica readiness); WardGatewayLocalPathTests and WardGatewayPartitionTests integration tests with Testcontainers; run-phase21-verification.sh	Done
22	Dashboard Gap Analysis Fixes — SOFA history chart (SofaHistory.vue) with organ-system breakdown; GCS history chart (GcsHistory.vue) with component tracking; qSOFA evaluation history (QsofaHistory.vue) backed by new qsofa_evaluations table and GET /qsofa/history API; patient banner (PatientBanner.vue) with demographics, age, blood type, allergies, emergency contact; encounter timeline (EncounterTimeline.vue) with merged chronological status/observation/alert events; medication administration markers on vital trend charts (medicationMarkerPlugin.js); composables patientFormat.js, timelineFormat.js, chartMedications.js; GET /encounters/{id}/gcs/history cursor-paginated GCS history endpoint; QsofaDetector now persists every evaluation; GapAnalysisFixTests integration tests; Vitest tests for all new components; run-phase22-verification.sh; docs/dashboard-gap-analysis.md	Done
17	Ward dashboard shell — Vue 3 + Vite + Pinia + Tailwind; virtual ward table (NEWS2-sorted, department filter); patient detail (vitals, scores, alerts, orders, sepsis bundle); alert center (global acknowledge/resolve); API polling; CORS-backed GET /encounters ward list	Done
18	Clinical review mode — Chart.js vital sign trends (5 charts), NEWS2 history chart, local replay controls, alert reasoning panel, medication context on alerts; fetchNews2History / fetchMedications; Vitest composable and component tests; docs/dashboard-guide.md	Done
19	Clinician feedback mode — six rating buttons per alert, optional notes, Feedback Summary with aggregate stats, JSON/CSV export, localStorage persistence; docs/clinical-testing-guide.md for doctor/nurse evaluation sessions	Done
25	Glasgow Coma Scale — GcsCalculator, GcsDetector, GcsScoringService; gcs_scores table; GCS_CRITICAL / GCS_WARNING alerts; gcs.scored outbox topic; NEWS2 consciousness GCS-first; qSOFA altered mentation sync; GcsController; Prometheus gcs_scores_total; GcsScoringTests; run-phase25-verification.sh	Done
26	SOFA scoring — SofaCalculator, SofaDetector, SofaLabCache, SofaVasopressorResolver, SofaScoringService; sofa_scores table with baseline + delta; SOFA_SEPSIS / SOFA_WARNING alerts; six new observation codes; SofaController; Kafka topic gcs.scored provisioned for CNS re-score; stale-encounter guard for Kafka replay; Prometheus sofa_scores_total; SofaScoringTests; run-phase26-verification.sh	Done
27	Sepsis-3 clinical refactor — SIRS removed (SirsDetector, SirsEvaluator deleted); qSOFA repositioned as bedside screening (QSOFA_SCREEN replaces QSOFA_WARNING); sepsis bundle now triggered only by SOFA_SEPSIS (delta ≥ 2) via SepsisAlertHandler; AlertCreationGuard prevents deprecated SEPSIS_WARNING creation; legacy alert types retained [Obsolete] for historical queries; migration AddQsofaScreenAlertType; SepsisRefactorTests, AlertCreationGuardTests; run-phase27-verification.sh	Done
28	Frontend GCS + SOFA + sepsis UI refactor — GcsEntryForm.vue (bedside GCS component entry); SofaScorePanel.vue (organ-system breakdown with staleness indicators); useGcs / useSofa composables; scoring Pinia store; ScoresPanel updated with GCS/SOFA display; SepsisBundlePanel and AlertReasoning refactored for Sepsis-3 alert types; Vitest tests for GCS entry, SOFA panel, scores panel, alert labels; run-phase28-verification.sh	Done
29	Simulator scenario expansion + clinical validation — three new scenarios (neurological-decline-gcs-01, sepsis-sofa-progression-01, sofa-partial-spo2-fallback-01); existing scenarios enriched with GCS/SOFA observations; ScenarioReplayHelper for end-to-end test replay; ClinicalRefactorEndToEndTests validates qSOFA screen → SOFA labs → bundle workflow; simulator polls GCS/SOFA scores; run-phase29-verification.sh	Done
30	FHIR R4 Inbound Facade — FhirIngestController (POST /fhir/R4/{Patient,Encounter,Observation,MedicationAdministration}); FhirMetadataController (CapabilityStatement); FhirBundleProcessor (transaction Bundles in dependency order); LoincCodeMapper (19 LOINC + 3 SNOMED CT → internal codes); FhirUnitConverter (°F→°C); ExternalResourceIdentifier table + ExternalIdentifierService for hospital MRN/visit number ↔ internal UUID linking; FhirApiKeyMiddleware (X-Api-Key auth); FhirExceptionFilter (→ OperationOutcome); PatientFhirMapper, EncounterFhirMapper, ObservationFhirMapper, MedicationAdministrationFhirMapper, FhirReferenceResolver; idempotent patient/encounter upserts (RegisterOrUpdateByIdentifierAsync, OpenOrUpdateByIdentifierAsync); configurable identifier systems, department codes, encounter class maps (FhirOptions); Prometheus fhir_ingest_total, fhir_mapping_errors_total; Mirth Connect integration guide; FhirIngestTests; run-phase30-verification.sh	Done
31	RBAC + Clinical Audit Logging — JWT bearer authentication (AuthService, AuthController); four clinical roles (Nurse, Physician, Admin, Integration) with 17 granular permissions; AuthorizePermission attribute on all controller actions; PermissionAuthorizationHandler + PermissionPolicyProvider resolve perm:* policies; CurrentUserService extracts identity from JWT claims; ClinicalUser entity with BCrypt password hashing; ClinicalAuditLog append-only table with before/after JSONB, user identity, IP, and correlation ID; AuditService writes log entries on clinical write actions (10 audit actions); AuditLogsController admin-only query with filters; FhirApiKeyOrJwtMiddleware dual auth for FHIR routes (JWT or X-Api-Key with multi-key rotation); alert acknowledgedBy set from authenticated user, not request body; four seeded demo users; frontend LoginView + auth Pinia store with localStorage token persistence; Vue router auth guard; RbacTests; run-phase31-verification.sh	Done

Ward dashboard: backend APIs (GET /encounters ward list with extended summary fields including SOFA/GCS/attending/admitted-at, GET /qsofa/current, GET /qsofa/history, GET /gcs/history, GET /sepsis-bundles hospital-wide list, CORS) and frontend SPA — EncountersListTests, QsofaCurrentTests, GapAnalysisFixTests, vigilcare-dashboard Vitest suite (replay scrubbing, feedback store, FeedbackButtons, FeedbackSummary, alert components, charts, ward table, ward sort, ward filter, department format, sepsis format, alert acknowledge, critical alert detect, handoff report, vitals form, GCS entry/history, SOFA panel/history, qSOFA history, scores panel, alert labels, PatientBanner, EncounterTimeline, medication chart markers, AcknowledgeModal, CriticalAlertBanner, DepartmentOverviewView, SepsisBoardView, VitalsEntryForm, useAlertStore, useWardStore).

Enhanced Dashboard (post-Phase 22): Major dashboard feature expansion addressing clinical workflow gaps. Department Overview (/departments) — unit-level snapshot cards showing patient count, critical/alert/bundle totals per department with acuity distribution bars; click-through to ward filtered by department. Sepsis Bundle Board (/sepsis) — real-time bundle compliance tracking with countdown timers to 1-hour deadline, urgency-sorted (overdue → at-risk → on-track), live 1-second tick updates. Critical Alert Notifications — CriticalAlertBanner surfaces new critical alerts from polling cycle with audible 880Hz two-tone alert, browser title flash, and native Notification API integration; mute toggle persisted in settings. Shift Handoff Report — HandoffReport.vue generates SBAR-format (Situation, Background, Assessment, Recommendation) structured reports for all ward patients, enriched with latest vitals, open alerts, pending orders, and sepsis bundle status; ward summary with department stats; print/PDF export. Vitals Entry Form — VitalsEntryForm.vue on patient detail page enables manual observation recording (7 vital parameters with AVPU dropdown) with client-side plausibility validation matching server-side ranges. Ward Table Enhancements — multi-column sorting (room, patient, department, NEWS2, qSOFA, sepsis, alerts) with sortable column headers, debounced patient search (name/MRN), quick-filter toggles (critical, has alerts, active sepsis), clear-all filters. Acknowledge Modal — role-aware acknowledgment with clinician identity pre-populated from JWT, role-specific guidance text, and acknowledgment note preview. Backend additions: GET /sepsis-bundles paginated hospital-wide list with SepsisBundleSummary (patient demographics, elements, deadlines); WardEncounterSummary extended with sofaScore, sofaDelta, gcsScore, gcsClassification, lastObservationAt, attendingPhysician, admittedAt.

Site & Gateway Registry (Phase 20): Central API manages clinical sites and ward edge nodes (gateways). Gateways authenticate via API key for heartbeat and sync upload. Shared VigilCare.ClinicalContracts class library defines sync DTOs consumed by both central API and ward gateway projects. Prometheus fleet health gauges track offline gateways and buffer depth per site.

Ward Gateway (Phase 21): VigilCare.WardGateway is a separate ASP.NET deployable with its own PostgreSQL (vigilcare_ward), Redis, and RabbitMQ — a local-first clinical path for ward edge nodes. Docker Compose services use the ward-gateway profile — start with docker compose --profile ward-gateway up -d. Observations are ingested locally with threshold evaluation and critical alert creation, then buffered for upload to the central API when the network link is available. Background services replicate encounter/patient data and alert thresholds from central on startup, report heartbeat status, and batch-upload buffered sync items. Local RabbitMQ provides ward-level paging and escalation independent of central connectivity. Integration tests (WardGatewayLocalPathTests, WardGatewayPartitionTests) validate the local ingest path and network partition/recovery workflow with Testcontainers.

Dashboard gap analysis (Phase 22): Addresses P0–P1 clinical gaps identified in docs/dashboard-gap-analysis.md. SOFA, GCS, and qSOFA now have history charts matching the existing NEWS2 history pattern. Patient detail gains a demographic banner (age, blood type, allergies, emergency contact) and an encounter timeline merging status changes, observation summaries, and alerts into a single chronological view. Vital trend charts overlay medication administration markers so clinicians can correlate drug timing with vital changes. Backend additions: GET /gcs/history cursor-paginated endpoint, qsofa_evaluations table with GET /qsofa/history for evaluation persistence.

Scoring pipeline (Phases 25–26): GCS components → gcs_scores + gcs.scored → SOFA CNS organ system; SOFA lab/vital observations → sofa_scores with baseline tracking → delta sepsis alerts when organ dysfunction worsens.

Sepsis-3 refactor (Phases 27–29): SIRS removed; qSOFA repositioned as bedside screening (QSOFA_SCREEN); SOFA delta ≥ 2 triggers SOFA_SEPSIS → sepsis bundle. Frontend gains GCS entry form and SOFA score panel. Eleven simulator scenarios validate the full clinical pipeline end-to-end.

FHIR R4 integration (Phase 30): Inbound facade accepts FHIR R4 JSON from integration engines (Mirth Connect, Rhapsody). Supports per-resource endpoints and transaction Bundles for ADT admit workflows. LOINC/SNOMED code mapping, Fahrenheit conversion, and external identifier linking enable drop-in EHR integration without changing the internal clinical pipeline.

RBAC + audit logging (Phase 31): JWT authentication with role-based permission gating on every endpoint. Four clinical roles with granular permissions. Append-only audit logging records who did what, when, and why — with before/after state snapshots for compliance and incident review. Frontend login page with token-based session management.

Post-phase hardening (after Phase 31):

• FHIR R4 read/search — FhirReadController adds GET /fhir/R4/Patient/{id}, GET /fhir/R4/Patient (search by identifier), GET /fhir/R4/Encounter/{id}, GET /fhir/R4/Encounter (search by patient/status); new fhir:read permission for Admin and Integration roles; CapabilityStatement updated to advertise read and searchType interactions for Patient and Encounter
• Alert threshold deletion — DELETE /alert-thresholds/{id} with THRESHOLD_DELETED audit action and Redis cache invalidation
• FHIR API key rotation — Fhir:ApiKeys array alongside existing Fhir:ApiKey for zero-downtime key rotation; constant-time comparison via CryptographicOperations.FixedTimeEquals prevents timing attacks
• Authorization failure logging — PermissionAuthorizationHandler logs denied requests with structured details (username, user ID, role, required permission, endpoint); Prometheus authorization_failures_total counter with permission and role labels
• JWT signing key validation — startup guard rejects keys shorter than 256 bits (HMAC-SHA256 minimum); prevents silent misconfiguration that would weaken token verification
• Concurrency hardening — SepsisBundleService.TryCreateBundleAsync wraps order + bundle creation in a single database transaction so the unique constraint rollback also reverts orphaned orders; PatientService.OpenEncounterAsync enforced by new partial unique index ix_encounters_patient_active_type on (patient_id, encounter_type) WHERE status = 'ACTIVE' with constraint-violation catch returning 409 Conflict; ConcurrencyTests validates parallel patient registration, sepsis bundle creation, observation idempotency, and encounter open race conditions
• New Prometheus metrics — fhir_read_total (resource_type, interaction, outcome), authorization_failures_total (permission, role)
• New audit actions — THRESHOLD_DELETED, AUTHORIZATION_DENIED

Optional follow-up: execute and document the Kafka replay demonstration for the data lake (reset data-lake-writer offsets, clear MinIO prefixes, restart API, confirm Parquet rebuild). See docs/plans/phase-9-plan.md § Replay demonstration.