# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Technology Stack

- **Java 21**
- **Vaadin 25.0.3** (server-side Java UI framework with Lumo theme)
- **Spring Boot 4.0.1**
- **Maven build system**

## Development Commands

```bash
./mvnw                           # Start in development mode (default goal)
./mvnw spring-boot:run           # Explicit development mode
./mvnw test                      # Run all tests
./mvnw test -Dtest=MyTest        # Run a single test class
./mvnw test -Dtest=MyTest#method # Run a single test method
./mvnw -Pproduction package      # Build production JAR
```

Application runs at http://localhost:8080 (auto-launches browser in dev mode).

## Project Structure

```
de.assecutor.aimailassistant/
├── Application.java             # Entry point with @SpringBootApplication
└── [feature packages]           # Add feature packages here
```

This project uses **feature-based packaging**: each feature is self-contained with its own entities, repositories, services, and UI views.

## Architecture Guidelines

### Adding Features

Create new packages under `de.assecutor.aimailassistant` (e.g., `de.assecutor.aimailassistant.mail`). Each feature package should contain:
- JPA entities
- Spring Data repositories
- Service classes with `@Transactional`
- Vaadin UI views

### Vaadin Patterns

- **Server-side rendering**: UI components are Java classes
- **Routing**: Use `@Route("path")` annotation on view classes
- **Navigation**: Use `@Menu` annotation to add views to automatic navigation
- **Lazy loading**: Use `VaadinSpringDataHelpers.toSpringPageRequest(query)` for Grid pagination
- **Styling**: Custom styles in `src/main/resources/META-INF/resources/styles.css`

### Spring Patterns

- Constructor injection (no `@Autowired` on fields)
- `@Transactional` for write operations
- `@Transactional(readOnly = true)` for read operations

## Database

No database configured yet. To add persistence, include Spring Data JPA and a database driver in pom.xml.