# Backend Modules

Backend modules provide feature-specific functionality for the Changemaker Lite platform. Each module follows a consistent architecture pattern with schemas, services, and routes.

## Module Architecture

Each module typically contains:

- **Schemas** (`*.schemas.ts`) - Zod validation schemas for requests/responses
- **Service** (`*.service.ts`) - Business logic and database operations
- **Routes** (`*.routes.ts`) - Express router definitions with middleware
- **Types** - TypeScript interfaces (when needed beyond Prisma types)

Modules may split routes into admin and public variants (e.g., `campaigns.routes.ts` and `campaigns-public.routes.ts`).

## Core Modules

### Authentication & User Management

- [**Auth Module**](auth.md) - JWT authentication, login, register, refresh tokens, logout
- [**Users Module**](users.md) - User CRUD, pagination, search, role management
- [**Settings Module**](settings.md) - Global site settings singleton

### Influence (Advocacy Campaigns)

- [**Campaigns Module**](campaigns.md) - Campaign CRUD, targeting, public views
- [**Representatives Module**](representatives.md) - Represent API integration, representative cache
- [**Responses Module**](responses.md) - Response wall, moderation, verification, upvoting

### Map & Location Services

- [**Locations Module**](locations.md) - Location CRUD, geocoding, NAR import, CSV operations
- [**Cuts Module**](cuts.md) - Polygon CRUD, spatial queries, point-in-polygon
- [**Shifts Module**](shifts.md) - Shift CRUD, volunteer signups, email notifications
- [**Canvass Module**](canvass.md) - Canvassing sessions, visit tracking, walking routes

### Content Management

- [**Pages Module**](pages.md) - Landing page CRUD, block library, MkDocs export
- [**Email Templates Module**](email-templates.md) - Template CRUD, variable processing, versioning
- [**Media Module**](media.md) - Video library, upload, metadata, reactions (Fastify API)

## Supporting Modules

### Infrastructure

- **Services Module** - Service health checks and monitoring
- **QR Module** - QR code PNG generation
- **Docs Module** - MkDocs and Code Server integration

### Integrations

- **Listmonk Module** - Newsletter sync, list management
- **Pangolin Module** - Tunnel management, resource configuration
- **Observability Module** - Prometheus/Grafana integration

### Email & Queuing

- **Campaign Emails Module** - Email tracking, statistics
- **Email Queue Module** - BullMQ queue administration
- **Postal Codes Module** - Postal code caching service

### Geocoding & Spatial

- **Geocoding Module** - Multi-provider geocoding (6 providers)
- **Tracking Module** - GPS tracking sessions (volunteer + admin)
- **Map Settings Module** - Map configuration singleton

## Module List

| Module | Purpose | Routes |
|--------|---------|--------|
| [auth](auth.md) | Authentication & sessions | `/api/auth/*` |
| [users](users.md) | User management | `/api/users/*` |
| [settings](settings.md) | Site settings | `/api/settings/*` |
| [campaigns](campaigns.md) | Advocacy campaigns | `/api/campaigns/*` |
| [representatives](representatives.md) | Representative lookup | `/api/representatives/*` |
| [responses](responses.md) | Response wall | `/api/responses/*` |
| [locations](locations.md) | Location database | `/api/locations/*` |
| [cuts](cuts.md) | Geographic cuts | `/api/cuts/*` |
| [shifts](shifts.md) | Volunteer shifts | `/api/shifts/*` |
| [canvass](canvass.md) | Canvassing system | `/api/canvass/*` |
| [pages](pages.md) | Landing pages | `/api/pages/*` |
| [media](media.md) | Video library | `/media-api/*` (port 4100) |

## Related Documentation

- [Backend Overview](../index.md)
- [Services](../services/index.md)
- [Middleware](../middleware/index.md)
- [Database Models](../../database/models/index.md)
- [API Reference](../../api-reference/index.md)