# Production Hardening & Architecture Security Report

**Engineers**: Principal Backend Engineer & DevSecOps Lead  
**Target System**: `AI Patient Onboarding FastAPI Microservice v1.0.0`  
**Deployment Target**: Dockerized Container Deployment / Cloud Infrastructure

---

## 1. System Architecture & Component Overview

```
[ Client / Web / Mobile ]
           │ (HTTPS / TLS 1.3)
           ▼
[ Reverse Proxy / Load Balancer ] (Nginx / Cloud Load Balancer)
           │ (Forwarded headers sanitized)
           ▼
[ FastAPI Application Service ] (Uvicorn / Docker Container)
   ├── Security Headers Middleware (X-Content-Type-Options, X-Frame-Options, Referrer-Policy)
   ├── Request Correlation Middleware (X-Request-ID)
   ├── Rate Limiting Middleware (Token Bucket Rate Limiter)
   ├── Service / Patient Authentication (Bearer / X-API-Key)
   └── IDOR Session Authorization (session.patient_id == auth.patient_id)
           │
     ┌─────┴──────────────────────────────┐
     ▼                                    ▼
[ SQLite Storage ]             [ External AI Services ]
 (onboarding_sessions,          ├── Google Gemini AI (gemini-3.6-flash)
  onboarding_state,             ├── Sarvam AI (Indic ASR & TTS)
  onboarding_messages)          └── OpenAI GPT-4o-mini (Fallback)
```

---

## 2. Implemented Production Hardening Safeguards

### A. Environment & Debug Controls
- **Debug Protection**: `DEBUG=false` enforced in production configuration.
- **Global Error Handling**: Uncaught exceptions are intercepted by a global FastAPI handler in `app/main.py`, returning a sanitized `{ "success": false, "error": { "code": "INTERNAL_SERVER_ERROR", "message": "An internal error occurred" } }` payload without revealing Python stack traces or file paths.

### B. Request Correlation & Traceability
- **Request ID Tracking**: Attached `X-Request-ID` middleware in `app/main.py`. Every HTTP request receives a unique tracking correlation ID in logs and headers.

### C. CORS & Security Response Headers
- **Explicit Domain Binding**: Replaced wildcard CORS (`*`) with explicit trusted domains (`https://onboarding.skyheal.ai`, `http://localhost:5173`).
- **HTTP Security Headers**: Attached `X-Content-Type-Options: nosniff`, `X-Frame-Options: DENY`, and `Referrer-Policy: strict-origin-when-cross-origin`.

### D. Upload Security & Payload Size Limits
- **Payload & Upload Caps**: Enforced 10MB file upload caps (`MAX_UPLOAD_SIZE=10485760`) in `app/api/documents.py`.
- **MIME Type Validation**: Restricted document uploads to valid clinical formats (`image/jpeg`, `image/png`, `image/webp`, `application/pdf`). Executables (`.exe`, `.sh`, `.bat`) are rejected immediately with `400 Bad Request`.

### E. Containerization & Deployment Configuration
- **Dockerfile Security**: Configured minimal `python:3.11-slim` base image running under a dedicated non-root user (`appuser`, UID 999). Docker health checks verify container readiness via `/health`.

---

## 3. Deployment Checklist

- [x] Environment template `.env.example` created.
- [x] Global exception handler attached to prevent error disclosure.
- [x] `X-Request-ID` request correlation middleware active.
- [x] CORS origins restricted to authorized domains.
- [x] Document upload MIME validation and 10MB size limits enforced.
- [x] Non-root Dockerfile & `.dockerignore` created.
- [x] Automated production security tests (`tests/production/test_production_security.py`) verified (5/5 Passed).