---
type: architecture
title: Key Files Index
description: One-line responsibility for important source and contract-test files, including strict event-window validation.
tags: [architecture, key-files, event-window, validation]
timestamp: 2026-07-22T14:24:08Z
---

# Backend

| File | Responsibility |
|---|---|
| `backend/src/main.ts` | Bootstraps Nest, middleware, OpenAPI, static assets, and SPA fallback. |
| `backend/src/app.module.ts` | Wires feature modules and global providers. |
| `backend/src/database/database.module.ts` | Configures TypeORM with SQLite. |
| `backend/src/database/database-init.service.ts` | Initializes the database and runs migrations. |
| `backend/src/common/guards/jwt-auth.guard.ts` | Global JWT authorization guard. |
| `backend/src/common/middleware/csrf.middleware.ts` | Double-submit CSRF protection. |
| `backend/src/common/services/event-status.service.ts` | Computes the event-window state machine. |
| `backend/src/common/services/sse-hub.service.ts` | In-process pub/sub for server-sent event streams. |
| `backend/src/modules/system/system.controller.ts` | Registers bootstrap, event status, settings, and SSE endpoints. |
| `backend/src/modules/system/system.service.ts` | Builds the public bootstrap payload from admin existence, settings, the theme loader, and password-policy configuration. |
| `backend/src/modules/admin/admin-general.controller.ts` | Registers admin general-settings and available-theme endpoints. |
| `backend/src/modules/admin/general.service.ts` | Reads/writes global settings, filters available theme files, and publishes the `general` SSE notification after updates. |
| `backend/src/modules/auth/auth.controller.ts` | Registers authentication and account endpoints. |
| `backend/src/modules/auth/auth.service.ts` | Handles sessions, authentication, registration, and password changes. |
| `backend/src/modules/uploads/uploads.controller.ts` | Registers admin-only multipart uploads, including Sharp-backed site-logo format validation. |
| `backend/src/modules/admin/dto/general.dto.ts` | Zod contract for `PUT /api/v1/admin/general/settings`; both event timestamps are required ISO-8601 values and end must be strictly after start. |
| `tests/backend/admin-general-event-window.spec.ts` | Focused contract tests for valid, empty, malformed, equal, and reversed event-window timestamps. |
| `tests/backend/admin-general-service.spec.ts` | General-settings schema and service tests, including per-field empty datetime failures and settings-event emission. |

# Frontend

| File | Responsibility |
|---|---|
| `frontend/src/main.ts` | Bootstraps Angular and registers HTTP interceptors. |
| `frontend/src/app/app.routes.ts` | Defines public, shell, child, and admin routes. |
| `frontend/src/app/core/services/bootstrap.service.ts` | Caches and exposes bootstrap state, refreshes it after admin updates, and applies the resolved theme. |
| `frontend/src/app/core/services/bootstrap.types.ts` | Defines bootstrap/theme payload types and maps theme tokens to CSS custom properties. |
| `frontend/src/app/core/services/admin.service.ts` | Calls admin settings, theme-list, category, and upload APIs. |
| `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services. |
| `frontend/src/app/core/services/auth.service.ts` | Signal-backed access token and current-user state; owns the cross-tab invalidation `BroadcastChannel` + `storage`-event fallback. |
| `frontend/src/app/core/services/auth-session-events.pure.ts` | Pure cross-tab message encoding/validation and namespaced constants used by the auth broadcast channel. |
| `frontend/src/app/core/services/authenticated-event-source.service.ts` | Fetch-based authenticated SSE transport with frame parsing, abort support, and a separate `'unauthorized'` event for `401`/`403`. |
| `frontend/src/app/core/services/event-status.store.ts` | Event state signal store, one-second countdown timer, and the optional `onUnauthorized` callback wiring. |
| `frontend/src/app/core/services/event-status.pure.ts` | Event payload types, transport interface (including `'unauthorized'` listener), pure countdown helpers, and the `LED_COLOR_BY_STATE` map used by the shell LED. |
| `frontend/src/app/features/home/home.component.ts` | Authenticated shell container; starts user and event state services, subscribes to peer invalidation, and navigates to `/login` when the session is invalidated elsewhere. |
| `frontend/src/app/features/shell/header/shell-header.component.ts` | Shell title, status LED (size/shape only — color comes from the pure map via `[style.background-color]`), countdown, and user menu. |
| `frontend/src/app/features/shell/tabs/quick-tabs.component.ts` | Main shell navigation tabs. |
| `frontend/src/app/features/shell/change-password/change-password-modal.component.ts` | Change-password form modal. |
| `frontend/src/app/features/admin/general.component.ts` | `AdminGeneralComponent` reactive form for `/admin/general` — per-field inline error rendering (page-title + event-start + event-end), logo upload wiring, welcome Markdown preview, event-state derivation, and SSE `general` event handling. |
| `frontend/src/app/features/admin/general.pure.ts` | Pure General Settings helpers, including required datetime validation, field messages, UTC conversion, and end-after-start validation. |
| `tests/frontend/admin-general-pure.spec.ts` | Pure client-contract tests for required event timestamps, datetime messaging, UTC conversion, and event-window ordering. |
| `tests/frontend/authenticated-event-source.spec.ts` | Tests SSE authorization, frame transport behavior, and the `401`/`403` unauthorized path. |
| `tests/frontend/auth-session-events.spec.ts` | Pure tests for cross-tab invalidation message encoding, payload validation, and `storage`-event filtering. |

# See also

- [Frontend Structure](/architecture/frontend-structure.md)
- [Authenticated Shell](/guides/authenticated-shell.md)
- [System Endpoints](/api/system.md)