lich make entity¶

Create a domain entity - the core of your business logic.

What is an Entity?¶

An entity represents a business concept with:

Properties - Data fields
Validation - Rules for data
Behavior - Domain logic methods

Entities are the heart of Clean Architecture.

Usage¶

lich make entity <Name>

Example¶

$ lich make entity Product

✅ Entity Product created!

Files created:
  backend/internal/entities/product.py
  backend/internal/entities/product_repository.py

Generated Code¶

Entity File (`product.py`)¶

"""
Product entity - domain model.
"""
from dataclasses import dataclass
from datetime import datetime
from typing import Optional
from uuid import UUID, uuid4


@dataclass
class Product:
    """Product domain entity."""

    id: UUID
    name: str
    description: Optional[str] = None
    price: float = 0.0
    created_at: datetime = None
    updated_at: datetime = None

    def __post_init__(self):
        if self.id is None:
            self.id = uuid4()
        if self.created_at is None:
            self.created_at = datetime.utcnow()

    # Add domain methods here
    def apply_discount(self, percent: float) -> None:
        """Apply discount to price."""
        self.price = self.price * (1 - percent / 100)

Repository Interface (`product_repository.py`)¶

"""
Product repository port - interface for data access.
"""
from abc import ABC, abstractmethod
from typing import List, Optional
from uuid import UUID

from internal.entities.product import Product


class ProductRepository(ABC):
    """Abstract repository for Product entity."""

    @abstractmethod
    async def get_by_id(self, id: UUID) -> Optional[Product]:
        """Get product by ID."""
        pass

    @abstractmethod
    async def get_all(self) -> List[Product]:
        """Get all products."""
        pass

    @abstractmethod
    async def save(self, product: Product) -> Product:
        """Save product."""
        pass

    @abstractmethod
    async def delete(self, id: UUID) -> bool:
        """Delete product."""
        pass

Why Use Entities?¶

Benefit	Description
🏛️ Domain Logic	Keep business rules in entities
🔒 Validation	Data is always valid
🧪 Testable	Easy to unit test
🔄 Reusable	Same entity across layers

Best Use Cases¶

1. User Management¶

lich make entity User
lich make entity Role
lich make entity Permission

2. E-commerce¶

lich make entity Product
lich make entity Order
lich make entity OrderItem
lich make entity Payment

3. Content Management¶

lich make entity Article
lich make entity Category
lich make entity Tag
lich make entity Comment

Naming Conventions¶

✅ Good	❌ Bad
`User`	`user`
`OrderItem`	`order_item`
`ProductCategory`	`productCategory`

Always use PascalCase for entity names.

Next Steps¶

After creating an entity:

# Create the service (business logic)
lich make service Product

# Create the API (endpoints)
lich make api products