Application Initialization

The FastAPI backend uses an explicit Lifespan context manager inside backend/app.py to ensure critical bootstrapping dependencies are satisfied before accepting web traffic.

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Startup Sequence

sequenceDiagram
    autonumber
    actor System
    participant App as FastAPI Runtime
    participant Dep as `check_dependencies.py`
    participant Adm as `setup_admin_user.py`
    participant Log as Simple Logger

    System->>App: Launch Uvicorn Server
    App->>App: Trigger `lifespan` startup hook

    %% Check 1
    App->>Log: Info ("Running dependency checks...")
    App->>Dep: Execute `main()` verification checks
    Dep-->>App: Exit status code (0 = success)

    %% Check 2
    App->>Log: Info ("Setting up admin user...")
    App->>Adm: Ensure default admin authentication records exist
    Adm-->>App: Exit status code (0 = success)

    App->>Log: Info ("Startup tasks completed successfully.")
    App-->>System: Server ready to receive incoming traffic

Pre-Flight Failure Handling

If either dependency evaluation or user provisioning exits with a non-zero exit code, the lifespan hook executes sys.exit(1). This fail-fast approach prevents deploying a compromised service to production.

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Global Middleware and Routing Registration

Following standard initialization procedures, global routing contexts are attached to the API instance:

app = FastAPI(title="Dashboard Generation API", version="0.1.0", lifespan=lifespan)

# Attached Global Middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Core Router Inclusions (Order Independent but Logically Segregated)
app.include_router(auth)
app.include_router(database_router)
app.include_router(dashboard_router)

Baseline Health Check Endpoints

The base API instance attaches direct root verifiers to validate load-balancer connections: - GET /: Outputs global application identifier payloads. - GET /health: Yields basic status indicators ({"status": "healthy"}).