Nestjs Prisma Vertical

NestJS + Prisma (Vertical Slice) — "Max Power" AI Architecture

AI Context & Token Optimization (Zero-Hallucination Rules)

1. Opinionated Framework: NestJS is mandatory. Unstructured frameworks like Express are BANNED. You must use decorators (@Controller, @Injectable) and modules.
2. Vertical Slice Architecture: Do NOT use traditional layered architectures (global controllers/, services/). Group all files by feature (e.g., src/features/auth/) to localize AI context and save memory tokens.
3. Strict TypeScript & Compile-Time Safety: The any type is strictly forbidden.
4. Prisma ORM as Source of Truth: Raw SQL queries are BANNED. You must modify schema.prisma, and rely on the compiler to catch invalid database calls.
5. Validation: All incoming requests MUST be validated using DTOs with class-validator and class-transformer.

Project Structure

src/
├── main.ts                     # Application entry point
├── app.module.ts               # Root module
├── core/                       # Core infrastructure (written once)
│   ├── prisma/                 # Prisma service and module
│   ├── guards/                 # Authentication/Authorization guards
│   ├── filters/                # Global exception filters
│   └── interceptors/             # Global interceptors
└── features/                   # ⬅️ Vertical Slices (Feature Modules)
    ├── auth/
    │   ├── auth.module.ts
    │   ├── auth.controller.ts
    │   ├── auth.service.ts
    │   └── dtos/
    │       ├── login.dto.ts
    │       └── register.dto.ts
    └── users/
        ├── users.module.ts
        ├── users.controller.ts
        └── users.service.ts

Naming Conventions

Architectural Patterns

Dependency Injection: Use NestJS constructor injection exclusively.

Prisma Workflow:

1. Modify prisma/schema.prisma.
2. Never write migrations manually. Use CLI commands to generate them.
3. Inject PrismaService into feature services to interact with the DB. The LSP will guide you with exact types.

Global Error Handling: Do not use inline try/catch for standard HTTP errors. Throw NestJS exceptions (ConflictException, NotFoundException) and let the global filter handle the JSON formatting.

Universal DateTime Governance

• Prisma Schema: Use DateTime fields with @db.Timestamptz() in the Prisma schema to enforce UTC storage. Never use @db.Date or @db.Timestamp without timezone.
• API DTOs (class-validator): Use @IsString() for ISO-8601 strings or @IsInt() for epoch ms. Banned: Date type in DTOs (serialization is unreliable cross-timezone).
• Clock Injection: Create a ClockProvider service (@Injectable) wrapping new Date() — inject it into feature services. Never call new Date() or Date.now() directly in business logic.
• API Format: All API responses MUST transmit datetimes as ISO-8601 UTC strings (2026-07-23T14:30:00.000Z) or epoch ms (number). Never transmit naive date strings.

Testing Strategies