Taste of the Codebase

A typical CQRS flow — command, handler, and service wired through NestJS DI:

// ── Command ──────────────────────────────────────────────
export class CreatePostCommand extends Command {
  constructor(
    public readonly userId: Uuid,
    public readonly dto: CreatePostDto,
  ) {
    super();
  }
}

// ── Handler ──────────────────────────────────────────────
@CommandHandler(CreatePostCommand)
export class CreatePostHandler {
  constructor(
    @InjectRepository(PostEntity)
    private repo: Repository<PostEntity>,
  ) {}

  async execute({ userId, dto }: CreatePostCommand): Promise<PostEntity> {
    return this.repo.save(this.repo.create({ ...dto, userId }));
  }
}

// ── Service ──────────────────────────────────────────────
@Injectable()
export class PostService {
  constructor(private commandBus: CommandBus) {}

  @Transactional()
  create(userId: Uuid, dto: CreatePostDto): Promise<PostEntity> {
    return this.commandBus.execute(new CreatePostCommand(userId, dto));
  }
}

Architecture

flowchart LR
    A[Request] --> B[Guard]
    B --> C[Controller]
    C --> D[Command / Query Bus]
    D --> E[Handler]
    E --> F[Service]
    F --> G[Repository]
    G --> H[(PostgreSQL)]

Every feature module follows this structure:

src/
├── common/              # Shared DTOs, base entity
├── constants/           # Enums, role types
├── database/            # Migrations, TypeORM config
├── decorators/          # @AuthUser, @UUIDParam, @UseDto
├── filters/             # Global exception filters
├── guards/              # Auth guards (JWT, roles)
├── i18n/                # Translation files (en_US, ru_RU)
├── interceptors/        # Language, translation interceptors
├── modules/
│   ├── auth/            # JWT auth (RS256), login/register
│   ├── user/            # User CRUD, RBAC
│   ├── post/            # Post CRUD, CQRS example
│   ├── agent/           # AI agent (ai-sdk v6)
│   └── chat/            # Chat history (JSONB)
├── shared/              # Global services, config
└── validators/          # Custom validation decorators

Full architecture →

Environment Variables

Copy .env.example → .env. Most variables come pre-configured with working defaults. You only need to change these:

Every other variable in .env.example has a working default for local development. Optional features (NATS, S3, Email, AI providers) are off by default — enable them when you need them.

All environment variables →

Multi-Runtime Support

Node is the primary runtime. Bun and Deno support is included for teams that prefer them.

Making It Your Own

1. Rename the project — update name in package.json
2. Update .env — replace the JWT keys and DB credentials with your own
3. Update LICENSE — change the author name
4. Customize this README — replace it with your project's docs

Documentation

1. Architecture — CQRS, repository pattern, DI, entity-DTO mapping
2. Setup & Development — first-time setup, scripts, debugging
3. Code Generation — NestJS schematics for scaffolding
4. Naming Cheatsheet — file, class, and variable conventions
5. Linting — Biome + ESLint setup
6. OpenAPI MCP — AI assistants calling your API

Community

Discuss on GitHub →

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