Small Business Inventory System FastAPI implementation

README.md

@@ -1,3 +1,116 @@
-# FastAPI Application
+# Small Business Inventory System
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A comprehensive FastAPI-based inventory management system designed for small businesses to track products, manage stock levels, and monitor supplier relationships.
+
+## Features
+
+- **Product Management**: Complete CRUD operations for products with SKU tracking
+- **Category Management**: Organize products into categories
+- **Supplier Management**: Track supplier information and relationships
+- **Inventory Tracking**: Real-time stock level monitoring with low-stock alerts
+- **Stock Movements**: Track all inventory movements (IN/OUT/ADJUSTMENTS)
+- **Reporting**: Stock reports and analytics
+- **API Documentation**: Auto-generated OpenAPI documentation
+
+## Quick Start
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+2. Run the application:
+```bash
+uvicorn main:app --reload
+```
+
+3. Access the API documentation at: `http://localhost:8000/docs`
+
+## API Endpoints
+
+### Products
+- `GET /products/` - List all products (with filtering options)
+- `POST /products/` - Create a new product
+- `GET /products/{product_id}` - Get product by ID
+- `GET /products/sku/{sku}` - Get product by SKU
+- `PUT /products/{product_id}` - Update product
+- `DELETE /products/{product_id}` - Delete product
+
+### Categories
+- `GET /categories/` - List all categories
+- `POST /categories/` - Create a new category
+- `GET /categories/{category_id}` - Get category by ID
+- `PUT /categories/{category_id}` - Update category
+- `DELETE /categories/{category_id}` - Delete category
+
+### Suppliers
+- `GET /suppliers/` - List all suppliers
+- `POST /suppliers/` - Create a new supplier
+- `GET /suppliers/{supplier_id}` - Get supplier by ID
+- `PUT /suppliers/{supplier_id}` - Update supplier
+- `DELETE /suppliers/{supplier_id}` - Delete supplier
+
+### Inventory
+- `POST /inventory/stock-movement` - Record stock movement
+- `GET /inventory/stock-movements` - List stock movements
+- `GET /inventory/low-stock` - Get low stock products
+- `GET /inventory/stock-report` - Get stock analytics
+- `PUT /inventory/adjust-stock/{product_id}` - Adjust stock levels
+
+### System
+- `GET /` - API information and links
+- `GET /health` - Health check endpoint
+
+## Database
+
+The system uses SQLite database with the following storage structure:
+- Database file: `/app/storage/db/db.sqlite`
+
+## Environment Variables
+
+No environment variables are required for basic operation. The system uses SQLite with default paths.
+
+## Development
+
+### Database Migrations
+
+The project uses Alembic for database migrations:
+
+```bash
+# Run migrations
+alembic upgrade head
+
+# Create new migration
+alembic revision --autogenerate -m "description"
+```
+
+### Code Quality
+
+The project uses Ruff for linting and formatting:
+
+```bash
+# Install ruff
+pip install ruff
+
+# Run linting
+ruff check .
+
+# Auto-fix issues
+ruff check . --fix
+```
+
+## Project Structure
+
+```
+├── main.py                 # FastAPI application entry point
+├── requirements.txt        # Python dependencies
+├── alembic.ini            # Alembic configuration
+├── alembic/               # Database migrations
+├── app/
+│   ├── db/                # Database configuration
+│   ├── models/            # SQLAlchemy models
+│   ├── schemas/           # Pydantic schemas
+│   └── routers/           # API route handlers
+└── storage/
+    └── db/                # SQLite database storage
+```

alembic.ini

@@ -0,0 +1,42 @@
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+version_path_separator = os
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+version_locations = %(here)s/alembic/versions
+
+[post_write_hooks]
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

alembic/env.py

@@ -0,0 +1,55 @@
+from logging.config import fileConfig
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from alembic import context
+import sys
+import os
+
+sys.path.append(os.path.dirname(os.path.dirname(os.path.realpath(__file__))))
+
+from app.db.base import Base
+from app.models.category import Category
+from app.models.supplier import Supplier
+from app.models.product import Product
+from app.models.stock_movement import StockMovement
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection, target_metadata=target_metadata
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

alembic/versions/001_initial_migration.py

@@ -0,0 +1,99 @@
+"""Initial migration
+
+Revision ID: 001
+Revises: 
+Create Date: 2024-01-01 12:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = '001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # Create categories table
+    op.create_table('categories',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(length=100), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('CURRENT_TIMESTAMP'), nullable=True),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_categories_id'), 'categories', ['id'], unique=False)
+    op.create_index(op.f('ix_categories_name'), 'categories', ['name'], unique=True)
+
+    # Create suppliers table
+    op.create_table('suppliers',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(length=100), nullable=False),
+        sa.Column('contact_person', sa.String(length=100), nullable=True),
+        sa.Column('email', sa.String(length=100), nullable=True),
+        sa.Column('phone', sa.String(length=20), nullable=True),
+        sa.Column('address', sa.Text(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('CURRENT_TIMESTAMP'), nullable=True),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_suppliers_id'), 'suppliers', ['id'], unique=False)
+    op.create_index(op.f('ix_suppliers_name'), 'suppliers', ['name'], unique=True)
+    op.create_index(op.f('ix_suppliers_email'), 'suppliers', ['email'], unique=True)
+
+    # Create products table
+    op.create_table('products',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(length=200), nullable=False),
+        sa.Column('sku', sa.String(length=100), nullable=False),
+        sa.Column('description', sa.Text(), nullable=True),
+        sa.Column('price', sa.Float(), nullable=False),
+        sa.Column('cost', sa.Float(), nullable=True),
+        sa.Column('category_id', sa.Integer(), nullable=True),
+        sa.Column('supplier_id', sa.Integer(), nullable=True),
+        sa.Column('quantity_in_stock', sa.Integer(), nullable=True),
+        sa.Column('min_stock_level', sa.Integer(), nullable=True),
+        sa.Column('max_stock_level', sa.Integer(), nullable=True),
+        sa.Column('is_active', sa.Boolean(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('CURRENT_TIMESTAMP'), nullable=True),
+        sa.Column('updated_at', sa.DateTime(timezone=True), nullable=True),
+        sa.ForeignKeyConstraint(['category_id'], ['categories.id'], ),
+        sa.ForeignKeyConstraint(['supplier_id'], ['suppliers.id'], ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_products_id'), 'products', ['id'], unique=False)
+    op.create_index(op.f('ix_products_name'), 'products', ['name'], unique=False)
+    op.create_index(op.f('ix_products_sku'), 'products', ['sku'], unique=True)
+
+    # Create stock_movements table
+    op.create_table('stock_movements',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('product_id', sa.Integer(), nullable=False),
+        sa.Column('movement_type', sa.Enum('IN', 'OUT', 'ADJUSTMENT', name='movementtype'), nullable=False),
+        sa.Column('quantity', sa.Integer(), nullable=False),
+        sa.Column('reference_number', sa.String(length=100), nullable=True),
+        sa.Column('notes', sa.Text(), nullable=True),
+        sa.Column('created_at', sa.DateTime(timezone=True), server_default=sa.text('CURRENT_TIMESTAMP'), nullable=True),
+        sa.ForeignKeyConstraint(['product_id'], ['products.id'], ),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_stock_movements_id'), 'stock_movements', ['id'], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f('ix_stock_movements_id'), table_name='stock_movements')
+    op.drop_table('stock_movements')
+    op.drop_index(op.f('ix_products_sku'), table_name='products')
+    op.drop_index(op.f('ix_products_name'), table_name='products')
+    op.drop_index(op.f('ix_products_id'), table_name='products')
+    op.drop_table('products')
+    op.drop_index(op.f('ix_suppliers_email'), table_name='suppliers')
+    op.drop_index(op.f('ix_suppliers_name'), table_name='suppliers')
+    op.drop_index(op.f('ix_suppliers_id'), table_name='suppliers')
+    op.drop_table('suppliers')
+    op.drop_index(op.f('ix_categories_name'), table_name='categories')
+    op.drop_index(op.f('ix_categories_id'), table_name='categories')
+    op.drop_table('categories')

app/db/base.py

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+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/session.py

@@ -0,0 +1,22 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/category.py

@@ -0,0 +1,15 @@
+from sqlalchemy import Column, Integer, String, Text, DateTime
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+class Category(Base):
+    __tablename__ = "categories"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(100), unique=True, index=True, nullable=False)
+    description = Column(Text)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    products = relationship("Product", back_populates="category")

app/models/product.py

@@ -0,0 +1,26 @@
+from sqlalchemy import Column, Integer, String, Text, Float, DateTime, ForeignKey, Boolean
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+class Product(Base):
+    __tablename__ = "products"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(200), index=True, nullable=False)
+    sku = Column(String(100), unique=True, index=True, nullable=False)
+    description = Column(Text)
+    price = Column(Float, nullable=False)
+    cost = Column(Float)
+    category_id = Column(Integer, ForeignKey("categories.id"))
+    supplier_id = Column(Integer, ForeignKey("suppliers.id"))
+    quantity_in_stock = Column(Integer, default=0)
+    min_stock_level = Column(Integer, default=0)
+    max_stock_level = Column(Integer)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    category = relationship("Category", back_populates="products")
+    supplier = relationship("Supplier", back_populates="products")
+    stock_movements = relationship("StockMovement", back_populates="product")

app/models/stock_movement.py

@@ -0,0 +1,23 @@
+from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Enum
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.db.base import Base
+import enum
+
+class MovementType(enum.Enum):
+    IN = "in"
+    OUT = "out"
+    ADJUSTMENT = "adjustment"
+
+class StockMovement(Base):
+    __tablename__ = "stock_movements"
+
+    id = Column(Integer, primary_key=True, index=True)
+    product_id = Column(Integer, ForeignKey("products.id"), nullable=False)
+    movement_type = Column(Enum(MovementType), nullable=False)
+    quantity = Column(Integer, nullable=False)
+    reference_number = Column(String(100))
+    notes = Column(Text)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+
+    product = relationship("Product", back_populates="stock_movements")

app/models/supplier.py

@@ -0,0 +1,18 @@
+from sqlalchemy import Column, Integer, String, Text, DateTime
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+class Supplier(Base):
+    __tablename__ = "suppliers"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(100), unique=True, index=True, nullable=False)
+    contact_person = Column(String(100))
+    email = Column(String(100), unique=True, index=True)
+    phone = Column(String(20))
+    address = Column(Text)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    products = relationship("Product", back_populates="supplier")

app/routers/categories.py

@@ -0,0 +1,52 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from typing import List
+from app.db.session import get_db
+from app.models.category import Category
+from app.schemas.category import Category as CategorySchema, CategoryCreate, CategoryUpdate
+
+router = APIRouter()
+
+@router.post("/", response_model=CategorySchema)
+def create_category(category: CategoryCreate, db: Session = Depends(get_db)):
+    db_category = Category(**category.dict())
+    db.add(db_category)
+    db.commit()
+    db.refresh(db_category)
+    return db_category
+
+@router.get("/", response_model=List[CategorySchema])
+def read_categories(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    categories = db.query(Category).offset(skip).limit(limit).all()
+    return categories
+
+@router.get("/{category_id}", response_model=CategorySchema)
+def read_category(category_id: int, db: Session = Depends(get_db)):
+    category = db.query(Category).filter(Category.id == category_id).first()
+    if category is None:
+        raise HTTPException(status_code=404, detail="Category not found")
+    return category
+
+@router.put("/{category_id}", response_model=CategorySchema)
+def update_category(category_id: int, category: CategoryUpdate, db: Session = Depends(get_db)):
+    db_category = db.query(Category).filter(Category.id == category_id).first()
+    if db_category is None:
+        raise HTTPException(status_code=404, detail="Category not found")
+    
+    update_data = category.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_category, field, value)
+    
+    db.commit()
+    db.refresh(db_category)
+    return db_category
+
+@router.delete("/{category_id}")
+def delete_category(category_id: int, db: Session = Depends(get_db)):
+    db_category = db.query(Category).filter(Category.id == category_id).first()
+    if db_category is None:
+        raise HTTPException(status_code=404, detail="Category not found")
+    
+    db.delete(db_category)
+    db.commit()
+    return {"message": "Category deleted successfully"}

app/routers/inventory.py

@@ -0,0 +1,89 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from typing import List
+from app.db.session import get_db
+from app.models.product import Product
+from app.models.stock_movement import StockMovement, MovementType
+from app.schemas.stock_movement import StockMovement as StockMovementSchema, StockMovementCreate
+from app.schemas.product import Product as ProductSchema
+
+router = APIRouter()
+
+@router.post("/stock-movement", response_model=StockMovementSchema)
+def create_stock_movement(movement: StockMovementCreate, db: Session = Depends(get_db)):
+    product = db.query(Product).filter(Product.id == movement.product_id).first()
+    if not product:
+        raise HTTPException(status_code=404, detail="Product not found")
+    
+    db_movement = StockMovement(**movement.dict())
+    db.add(db_movement)
+    
+    if movement.movement_type == MovementType.IN:
+        product.quantity_in_stock += movement.quantity
+    elif movement.movement_type == MovementType.OUT:
+        if product.quantity_in_stock < movement.quantity:
+            raise HTTPException(status_code=400, detail="Insufficient stock")
+        product.quantity_in_stock -= movement.quantity
+    elif movement.movement_type == MovementType.ADJUSTMENT:
+        product.quantity_in_stock = movement.quantity
+    
+    db.commit()
+    db.refresh(db_movement)
+    return db_movement
+
+@router.get("/stock-movements", response_model=List[StockMovementSchema])
+def read_stock_movements(skip: int = 0, limit: int = 100, product_id: int = None, db: Session = Depends(get_db)):
+    query = db.query(StockMovement)
+    if product_id:
+        query = query.filter(StockMovement.product_id == product_id)
+    movements = query.order_by(StockMovement.created_at.desc()).offset(skip).limit(limit).all()
+    return movements
+
+@router.get("/low-stock", response_model=List[ProductSchema])
+def get_low_stock_products(db: Session = Depends(get_db)):
+    products = db.query(Product).filter(
+        Product.quantity_in_stock <= Product.min_stock_level,
+        Product.is_active == True
+    ).all()
+    return products
+
+@router.get("/stock-report")
+def get_stock_report(db: Session = Depends(get_db)):
+    total_products = db.query(Product).filter(Product.is_active == True).count()
+    low_stock_count = db.query(Product).filter(
+        Product.quantity_in_stock <= Product.min_stock_level,
+        Product.is_active == True
+    ).count()
+    out_of_stock_count = db.query(Product).filter(
+        Product.quantity_in_stock == 0,
+        Product.is_active == True
+    ).count()
+    
+    total_stock_value = db.query(Product).filter(Product.is_active == True).all()
+    total_value = sum(p.quantity_in_stock * (p.cost or 0) for p in total_stock_value)
+    
+    return {
+        "total_products": total_products,
+        "low_stock_products": low_stock_count,
+        "out_of_stock_products": out_of_stock_count,
+        "total_stock_value": total_value
+    }
+
+@router.put("/adjust-stock/{product_id}")
+def adjust_stock(product_id: int, new_quantity: int, notes: str = None, db: Session = Depends(get_db)):
+    product = db.query(Product).filter(Product.id == product_id).first()
+    if not product:
+        raise HTTPException(status_code=404, detail="Product not found")
+    
+    movement = StockMovement(
+        product_id=product_id,
+        movement_type=MovementType.ADJUSTMENT,
+        quantity=new_quantity,
+        notes=notes or f"Stock adjusted to {new_quantity}"
+    )
+    
+    db.add(movement)
+    product.quantity_in_stock = new_quantity
+    db.commit()
+    
+    return {"message": f"Stock adjusted to {new_quantity}", "new_quantity": new_quantity}

app/routers/products.py

@@ -0,0 +1,78 @@
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.orm import Session
+from typing import List, Optional
+from app.db.session import get_db
+from app.models.product import Product
+from app.schemas.product import Product as ProductSchema, ProductCreate, ProductUpdate
+
+router = APIRouter()
+
+@router.post("/", response_model=ProductSchema)
+def create_product(product: ProductCreate, db: Session = Depends(get_db)):
+    db_product = Product(**product.dict())
+    db.add(db_product)
+    db.commit()
+    db.refresh(db_product)
+    return db_product
+
+@router.get("/", response_model=List[ProductSchema])
+def read_products(
+    skip: int = 0, 
+    limit: int = 100, 
+    category_id: Optional[int] = Query(None),
+    supplier_id: Optional[int] = Query(None),
+    is_active: Optional[bool] = Query(None),
+    low_stock: Optional[bool] = Query(None),
+    db: Session = Depends(get_db)
+):
+    query = db.query(Product)
+    
+    if category_id:
+        query = query.filter(Product.category_id == category_id)
+    if supplier_id:
+        query = query.filter(Product.supplier_id == supplier_id)
+    if is_active is not None:
+        query = query.filter(Product.is_active == is_active)
+    if low_stock:
+        query = query.filter(Product.quantity_in_stock <= Product.min_stock_level)
+    
+    products = query.offset(skip).limit(limit).all()
+    return products
+
+@router.get("/{product_id}", response_model=ProductSchema)
+def read_product(product_id: int, db: Session = Depends(get_db)):
+    product = db.query(Product).filter(Product.id == product_id).first()
+    if product is None:
+        raise HTTPException(status_code=404, detail="Product not found")
+    return product
+
+@router.put("/{product_id}", response_model=ProductSchema)
+def update_product(product_id: int, product: ProductUpdate, db: Session = Depends(get_db)):
+    db_product = db.query(Product).filter(Product.id == product_id).first()
+    if db_product is None:
+        raise HTTPException(status_code=404, detail="Product not found")
+    
+    update_data = product.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_product, field, value)
+    
+    db.commit()
+    db.refresh(db_product)
+    return db_product
+
+@router.delete("/{product_id}")
+def delete_product(product_id: int, db: Session = Depends(get_db)):
+    db_product = db.query(Product).filter(Product.id == product_id).first()
+    if db_product is None:
+        raise HTTPException(status_code=404, detail="Product not found")
+    
+    db.delete(db_product)
+    db.commit()
+    return {"message": "Product deleted successfully"}
+
+@router.get("/sku/{sku}", response_model=ProductSchema)
+def read_product_by_sku(sku: str, db: Session = Depends(get_db)):
+    product = db.query(Product).filter(Product.sku == sku).first()
+    if product is None:
+        raise HTTPException(status_code=404, detail="Product not found")
+    return product

app/routers/suppliers.py

@@ -0,0 +1,52 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from typing import List
+from app.db.session import get_db
+from app.models.supplier import Supplier
+from app.schemas.supplier import Supplier as SupplierSchema, SupplierCreate, SupplierUpdate
+
+router = APIRouter()
+
+@router.post("/", response_model=SupplierSchema)
+def create_supplier(supplier: SupplierCreate, db: Session = Depends(get_db)):
+    db_supplier = Supplier(**supplier.dict())
+    db.add(db_supplier)
+    db.commit()
+    db.refresh(db_supplier)
+    return db_supplier
+
+@router.get("/", response_model=List[SupplierSchema])
+def read_suppliers(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    suppliers = db.query(Supplier).offset(skip).limit(limit).all()
+    return suppliers
+
+@router.get("/{supplier_id}", response_model=SupplierSchema)
+def read_supplier(supplier_id: int, db: Session = Depends(get_db)):
+    supplier = db.query(Supplier).filter(Supplier.id == supplier_id).first()
+    if supplier is None:
+        raise HTTPException(status_code=404, detail="Supplier not found")
+    return supplier
+
+@router.put("/{supplier_id}", response_model=SupplierSchema)
+def update_supplier(supplier_id: int, supplier: SupplierUpdate, db: Session = Depends(get_db)):
+    db_supplier = db.query(Supplier).filter(Supplier.id == supplier_id).first()
+    if db_supplier is None:
+        raise HTTPException(status_code=404, detail="Supplier not found")
+    
+    update_data = supplier.dict(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(db_supplier, field, value)
+    
+    db.commit()
+    db.refresh(db_supplier)
+    return db_supplier
+
+@router.delete("/{supplier_id}")
+def delete_supplier(supplier_id: int, db: Session = Depends(get_db)):
+    db_supplier = db.query(Supplier).filter(Supplier.id == supplier_id).first()
+    if db_supplier is None:
+        raise HTTPException(status_code=404, detail="Supplier not found")
+    
+    db.delete(db_supplier)
+    db.commit()
+    return {"message": "Supplier deleted successfully"}

app/schemas/category.py

@@ -0,0 +1,22 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+
+class CategoryBase(BaseModel):
+    name: str
+    description: Optional[str] = None
+
+class CategoryCreate(CategoryBase):
+    pass
+
+class CategoryUpdate(BaseModel):
+    name: Optional[str] = None
+    description: Optional[str] = None
+
+class Category(CategoryBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True

app/schemas/product.py

@@ -0,0 +1,44 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+from app.schemas.category import Category
+from app.schemas.supplier import Supplier
+
+class ProductBase(BaseModel):
+    name: str
+    sku: str
+    description: Optional[str] = None
+    price: float
+    cost: Optional[float] = None
+    category_id: Optional[int] = None
+    supplier_id: Optional[int] = None
+    quantity_in_stock: int = 0
+    min_stock_level: int = 0
+    max_stock_level: Optional[int] = None
+    is_active: bool = True
+
+class ProductCreate(ProductBase):
+    pass
+
+class ProductUpdate(BaseModel):
+    name: Optional[str] = None
+    sku: Optional[str] = None
+    description: Optional[str] = None
+    price: Optional[float] = None
+    cost: Optional[float] = None
+    category_id: Optional[int] = None
+    supplier_id: Optional[int] = None
+    quantity_in_stock: Optional[int] = None
+    min_stock_level: Optional[int] = None
+    max_stock_level: Optional[int] = None
+    is_active: Optional[bool] = None
+
+class Product(ProductBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+    category: Optional[Category] = None
+    supplier: Optional[Supplier] = None
+
+    class Config:
+        from_attributes = True

app/schemas/stock_movement.py

@@ -0,0 +1,21 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+from app.models.stock_movement import MovementType
+
+class StockMovementBase(BaseModel):
+    product_id: int
+    movement_type: MovementType
+    quantity: int
+    reference_number: Optional[str] = None
+    notes: Optional[str] = None
+
+class StockMovementCreate(StockMovementBase):
+    pass
+
+class StockMovement(StockMovementBase):
+    id: int
+    created_at: datetime
+
+    class Config:
+        from_attributes = True

app/schemas/supplier.py

@@ -0,0 +1,28 @@
+from pydantic import BaseModel, EmailStr
+from datetime import datetime
+from typing import Optional
+
+class SupplierBase(BaseModel):
+    name: str
+    contact_person: Optional[str] = None
+    email: Optional[EmailStr] = None
+    phone: Optional[str] = None
+    address: Optional[str] = None
+
+class SupplierCreate(SupplierBase):
+    pass
+
+class SupplierUpdate(BaseModel):
+    name: Optional[str] = None
+    contact_person: Optional[str] = None
+    email: Optional[EmailStr] = None
+    phone: Optional[str] = None
+    address: Optional[str] = None
+
+class Supplier(SupplierBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True

main.py

@@ -0,0 +1,41 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from app.routers import products, categories, suppliers, inventory
+from app.db.session import engine
+from app.db.base import Base
+
+Base.metadata.create_all(bind=engine)
+
+app = FastAPI(
+    title="Small Business Inventory System",
+    description="A comprehensive inventory management system for small businesses",
+    version="1.0.0",
+    openapi_url="/openapi.json"
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(products.router, prefix="/products", tags=["products"])
+app.include_router(categories.router, prefix="/categories", tags=["categories"])
+app.include_router(suppliers.router, prefix="/suppliers", tags=["suppliers"])
+app.include_router(inventory.router, prefix="/inventory", tags=["inventory"])
+
+@app.get("/")
+async def root():
+    return {
+        "title": "Small Business Inventory System",
+        "description": "A comprehensive inventory management system for small businesses",
+        "version": "1.0.0",
+        "documentation": "/docs",
+        "health_check": "/health"
+    }
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy", "service": "inventory-system"}

requirements.txt

@@ -0,0 +1,7 @@
+fastapi==0.104.1
+uvicorn[standard]==0.24.0
+sqlalchemy==2.0.23
+alembic==1.12.1
+pydantic==2.5.0
+python-multipart==0.0.6
+ruff==0.1.6