# Architecture and Design

## Workspace Architecture

AASPortal is a **monorepo** using npm workspaces with the following distinct packages:

![AASPortal package diagram](./images/PackageDiagram.png "AASPortal package diagram")

For detailed information about each workspace, see the [Workspace Documentation](workspaces.md).

## AASPortal (Frontend)

**aas-portal** is an Angular-based web application for visualizing and managing Asset Administration Shells.

**Key Technologies:**
- **Angular 20.x**: Modern reactive framework with signals support
- **NgRx**: State management for predictable application state
- **Bootstrap 5**: Responsive UI with ng-bootstrap components
- **Chart.js**: Data visualization capabilities
- **i18n**: Multi-language support via ngx-translate

**Architecture:**
- Component-based architecture with lazy loading
- Reactive state management with NgRx Store
- OnPush change detection for performance
- Service layer for API communication

## AASNode (Backend)

**aas-node** is a Node.js/Express.js backend server that provides a unified REST API for accessing Asset Administration Shells from multiple sources.

**Key Technologies:**
- **Express.js**: Fast, minimalist web framework
- **JWT (jsonwebtoken)**: Token-based authentication (HS256/RS256)
- **OpenAPI/Swagger**: Auto-generated API documentation via TSOA and swagger-ui-express
- **node-opcua**: OPC UA server connectivity for industrial assets
- **MongoDB**: User storage
- **WebDAV Client**: Remote file system access

**Features:**
- Multi-source AAS providers (file system, OPC UA, AASX Server, AAS Registry)
- Background scanning and indexing of AAS containers
- Real-time data subscriptions
- Template management for AAS creation
- AASX package handling via aas-package library

## AASServer

**aas-server** is a standalone AAS repository server with an IDTA Part 2 compliant API.

**Key Technologies:**
- **Express.js**: Web framework
- **OpenAPI/Swagger**: Standards-compliant API documentation via TSOA
- **aas-package**: AASX file handling

**Features:**
- IDTA specification Part 2 compliant REST API
- Asset Administration Shell repository
- Submodel repository
- Concept description repository