bilhej/AGENTS.md

AGENTS.md — BilHej / Bilhälsning.se

Project-specific instructions for OpenCode. Commit this file.

---

Project Identity

BilHej is a web platform letting Swedish residents send physical letters to vehicle owners by entering a registration number. The sender composes a letter, pays 49 SEK, and BilHej prints+mails it via PostNord. The sender never sees the recipient's name or address.

Phase 0 (current): Manual workflow. No Transportstyrelsen or PostNord API integration yet. Owner address is obtained manually by a human and entered into the admin panel.

Tech stack: Vue.js 3 (Vite, Pinia) frontend + Java 21 Spring Boot 4 backend + PostgreSQL 16. Deployed via Docker Compose.

---

Build, Lint, Test & Run Commands

Always run these after making changes to verify nothing is broken.

Gradle lives at repo root. All commands below run from the repo root unless noted.

Quick start (everything)

cp .env.example .env    # first time only, then fill in keys
docker compose up -d    # starts postgres, backend, frontend
./gradlew up            # same as above (Gradle wrapper)

All-in-one

./gradlew check         # frontend lint → frontend test → backend test → integration test
./gradlew up            # docker compose up -d
./gradlew down          # docker compose down
./gradlew reset         # docker compose down -v && docker compose up -d (full DB reset)

Frontend (Vue.js 3 + Vite)

cd frontend
npm install          # first time only
npm run dev          # dev server on :3000 with HMR
npm run build        # production build
npm run lint         # ESLint
npm run test         # vitest

Backend (Spring Boot 4 + Java 21)

./gradlew :backend:bootRun    # dev server on :8080
./gradlew :backend:test       # JUnit 5 + Mockito (backend only)

Stripe webhooks (local testing)

stripe listen --forward-to localhost:8080/api/webhooks/stripe

Database

Flyway migrations run automatically on Spring Boot startup. Migration files live in backend/src/main/resources/db/migration/. Naming: V<number>__descriptive_name.sql.

To reset: docker compose down -v && docker compose up -d.

---

Project Structure

bilhej/
├── frontend/                # Vue.js 3 SPA (Vite)
│   ├── src/
│   │   ├── pages/           # Route-level page components
│   │   ├── components/      # Reusable UI components
│   │   ├── composables/     # useXxx.ts shared logic
│   │   ├── stores/          # Pinia stores
│   │   ├── api/             # API client modules
│   │   ├── router/          # Vue Router config
│   │   └── assets/          # Static files, CSS
│   └── ...
├── backend/                 # Spring Boot 4 (Java 21) — Gradle subproject
│   ├── build.gradle              # Spring Boot plugin, Java deps, test config
│   ├── src/main/java/se/bilhalsning/
│   │   ├── config/          # @Configuration classes
│   │   ├── controller/      # REST controllers
│   │   ├── dto/             # Request/response DTOs
│   │   ├── entity/          # JPA entities
│   │   ├── repository/      # Spring Data JPA repos
│   │   ├── service/         # Business logic
│   │   ├── security/        # JWT filter, UserDetailsService
│   │   ├── exception/       # Custom exceptions + @ControllerAdvice
│   │   └── mapper/          # Entity ↔ DTO mapping
│   └── src/main/resources/
│       ├── application.yml            # default (H2, IDE dev)
│       ├── application-docker.yml     # docker profile (PostgreSQL)
│       └── db/migration/              # Flyway migrations
├── docker/                  # Dockerfiles
│   ├── backend.Dockerfile              # dev: JDK 21 + gradle :backend:bootRun
│   ├── backend.prod.Dockerfile         # prod: multi-stage (Gradle build → JRE Alpine, non-root)
│   ├── frontend.Dockerfile             # dev: Node 24 + vite dev server
│   ├── frontend.prod.Dockerfile        # prod: multi-stage (Node build → nginx)
│   ├── nginx.conf                      # prod: SPA fallback + /api reverse proxy
│   └── entrypoint.sh                   # prod: self-signed cert generation
├── docker-compose.yml       # dev: postgres + backend (bootRun) + frontend (Vite HMR)
├── docker-compose.prod.yml  # prod: multi-stage images, no source mounts, restart always
├── gradlew                  # Gradle wrapper (repo root)
├── gradle/
│   └── wrapper/
├── settings.gradle          # rootProject.name + include 'backend'
├── build.gradle             # convenience tasks: check, up, down, reset
├── .env.example
├── AGENTS.md                # This file
├── README.md
├── REQUIREMENTS.md
└── CODING_GUIDELINES.md

---

Conventions (Summary)

Full details in @CODING_GUIDELINES.md. Key rules:

Both sides

• Code and comments in English. User-facing strings in Swedish.
• No commented-out code. Delete it.
• Functions stay small (<30 lines).

Git

• Create feature/*, fix/*, or chore/* branches from develop.
• Never commit directly to master or develop.
• Merge strategy: fast-forward or merge — either is fine.
• Commit messages must be thorough: describe what changed, why, and list concrete changes as bullet points. Never write single-line "feat: add X" messages.

Frontend (Vue.js 3)

• <script setup> with Composition API only. Never Options API.
• File naming: PascalCase for pages/components, camelCase (useXxx) for composables.
• API calls live in api/ modules, never in components.
• Component styles are scoped.

Backend (Spring Boot 3)

• Constructor injection with @RequiredArgsConstructor. No @Autowired.
• DTOs: prefer Java records. No bare entities in responses.
• Controllers stay thin. All logic in services.
• Use @ControllerAdvice for consistent error responses ({ "message": "..." }).
• No Lombok beyond @RequiredArgsConstructor.

Database

• Table names: snake_case, plural. PKs: UUID, generated in code.
• Timestamps: created_at, updated_at. Use Instant in Java.
• Enums: stored as VARCHAR.
• Index every FK and every column used in WHERE.

---

Critical Gotchas

Phase 0: Address lookup is MANUAL

There is no Transportstyrelsen API integration yet. When an order is paid, a human must manually request the owner address via the "Fråga om fordonsägare" form and update the admin panel. Do NOT write code that calls an API that doesn't exist yet. The backend should store the order and wait for an admin to mark it as processed.

Never store recipient addresses

After the address is used to mail the letter, it must be deleted. The Order entity must NOT have an address field. The address lookup and mailing are external/human processes in Phase 0.

Stripe webhook signature verification

Always verify stripe-signature header using STRIPE_WEBHOOK_SECRET. Webhook endpoint is public (no auth). Without signature verification an attacker could mark orders as paid.

Swedish UI strings

All text visible to end users must be in Swedish. Button labels, error messages, validation text, email content, template bodies. Only developer facing content is in English.

JWT in Authorization header

Backend expects Authorization: Bearer <token>. Frontend interceptor must attach this to all API calls. Unauthorized APIs (register, login, webhook, public vehicle info) must be excluded from the Spring Security filter chain.

---

Testing Approach

Backend

• JUnit 5 + Mockito for service layer tests.
• @WebMvcTest for controller tests.
• Test naming: shouldXxxWhenYyy.
• Use test profile with H2 or Testcontainers for DB-dependent tests.
• Flyway migrations must run in test profile too.

Frontend

• Vitest for composables and utility functions.
• Component tests with Vue Test Utils where needed.
• E2E tests deferred to Phase 1.

CI (future)

• ./gradlew check and npm run test && npm run lint must pass before merge.

---

External References

For detailed conventions, load @CODING_GUIDELINES.md. For product requirements and business logic, load @REQUIREMENTS.md. For setup and quick start, load @README.md.

These are lazy-loaded by OpenCode — only read them when the task at hand needs the detail.