Implement user authentication service with FastAPI and SQLite

2025-06-05 11:01:49 +00:00 · 2025-06-05 11:01:49 +00:00 · 96d90a5f04
commit 96d90a5f04
parent 21ffddffb6
30 changed files with 1172 additions and 2 deletions
--- a/README.md
+++ b/README.md
@ -1,3 +1,149 @@
-# FastAPI Application
+# User Authentication Service

-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A FastAPI service that provides user authentication functionality including registration, login, and user management.
+
+## Features
+
+- User registration and login
+- JWT-based authentication
+- Password hashing with bcrypt
+- User profile management
+- Role-based access control (superuser capabilities)
+- Email verification flags
+- SQLite database with SQLAlchemy and Alembic migrations
+- Health check endpoint
+
+## Requirements
+
+- Python 3.8+
+- FastAPI
+- SQLAlchemy
+- Alembic
+- Uvicorn
+- See `requirements.txt` for complete list
+
+## Setup
+
+### 1. Clone the repository
+
+```bash
+git clone <repository-url>
+cd userauthenticationservice
+```
+
+### 2. Set up a virtual environment (optional but recommended)
+
+```bash
+python -m venv venv
+source venv/bin/activate  # On Windows: venv\Scripts\activate
+```
+
+### 3. Install dependencies
+
+```bash
+pip install -r requirements.txt
+```
+
+### 4. Set environment variables
+
+Create a `.env` file in the project root with the following content:
+
+```
+SECRET_KEY=your-secret-key-here
+ACCESS_TOKEN_EXPIRE_MINUTES=10080  # 7 days
+```
+
+### 5. Run migrations to create the database
+
+```bash
+alembic upgrade head
+```
+
+### 6. Start the application
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+## API Endpoints
+
+### Authentication
+
+- `POST /api/v1/auth/register` - Register a new user
+- `POST /api/v1/auth/login` - OAuth2 compatible token login (form)
+- `POST /api/v1/auth/login/json` - JSON compatible token login
+
+### Users
+
+- `GET /api/v1/users/me` - Get current user information (requires authentication)
+- `PUT /api/v1/users/me` - Update current user information (requires authentication)
+- `GET /api/v1/users` - List all users (requires superuser)
+- `GET /api/v1/users/{user_id}` - Get user by ID (requires authentication)
+- `PUT /api/v1/users/{user_id}` - Update user by ID (requires superuser)
+
+### Health Check
+
+- `GET /health` - Check API health status
+
+## API Documentation
+
+Interactive API documentation is available at:
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## Environment Variables
+
+| Variable | Description | Default |
+|----------|-------------|---------|
+| SECRET_KEY | JWT secret key | "CHANGE_THIS_TO_A_SECURE_SECRET_IN_PRODUCTION" |
+| ALGORITHM | JWT algorithm | "HS256" |
+| ACCESS_TOKEN_EXPIRE_MINUTES | Token expiration time in minutes | 10080 (7 days) |
+| PROJECT_NAME | Project name | "User Authentication Service" |
+
+## Project Structure
+
+```
+.
+├── alembic.ini
+├── app
+│   ├── api
+│   │   ├── deps.py               # Dependency functions
+│   │   ├── endpoints
+│   │   │   ├── auth.py           # Authentication endpoints
+│   │   │   └── users.py          # User management endpoints
+│   │   └── api.py                # API router
+│   ├── core
+│   │   ├── config.py             # App configuration
+│   │   ├── database.py           # Database setup
+│   │   ├── errors.py             # Error handling
+│   │   ├── health.py             # Health check endpoint
+│   │   └── security.py           # Security utilities
+│   ├── crud
+│   │   └── user.py               # User CRUD operations
+│   ├── models
+│   │   ├── health.py             # Health check model
+│   │   └── user.py               # User database model
+│   └── schemas
+│       └── user.py               # User Pydantic schemas
+├── main.py                       # Application entry point
+├── migrations                    # Alembic migrations
+│   ├── env.py
+│   ├── script.py.mako
+│   └── versions
+│       └── initial_migration.py  # Initial database schema
+└── requirements.txt              # Dependencies
+```
+
+## Security Notes
+
+For production deployment:
+
+1. Replace the default SECRET_KEY with a secure random key
+2. Consider setting up HTTPS
+3. Review the default token expiration time
+4. Implement rate limiting for auth endpoints
+5. Add more robust logging
+6. Consider additional security measures like IP-based blocking
--- a/alembic.ini
+++ b/alembic.ini
@ -0,0 +1,111 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration file names; The default value is %%(rev)s_%%(slug)s
+# Uncomment the line below if you want the files to be prepended with date and time
+# see https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file
+# for all available tokens
+# file_template = %%(year)d_%%(month).2d_%%(day).2d_%%(hour).2d%%(minute).2d-%%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; This defaults
+# to migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# set to 'true' to search source files recursively
+# in each "version_locations" directory
+# new in Alembic version 1.10
+# recursive_version_locations = false
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite database URL
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# Logging configuration
+[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
--- a/app/init.py
+++ b/app/init.py
--- a/app/api/init.py
+++ b/app/api/init.py
--- a/app/api/api.py
+++ b/app/api/api.py
@ -0,0 +1,7 @@
+from fastapi import APIRouter
+
+from app.api.endpoints import auth, users
+
+api_router = APIRouter(prefix="/api/v1")
+api_router.include_router(auth.router, tags=["authentication"])
+api_router.include_router(users.router, tags=["users"])
--- a/app/api/deps.py
+++ b/app/api/deps.py
@ -0,0 +1,70 @@
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError, jwt
+from pydantic import ValidationError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.config import settings
+from app.core.database import get_db
+from app.crud import user as crud_user
+from app.models.user import User
+from app.schemas.user import TokenPayload
+
+# Create OAuth2 password bearer scheme
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl=f"{settings.API_V1_STR}/auth/login")
+
+
+async def get_current_user(
+    db: AsyncSession = Depends(get_db),
+    token: str = Depends(oauth2_scheme),
+) -> User:
+    """
+    Validate access token and return current user.
+    """
+    try:
+        # Decode JWT token
+        payload = jwt.decode(
+            token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM]
+        )
+        token_data = TokenPayload(**payload)
+    except (JWTError, ValidationError):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+    # Get user from database
+    user = await crud_user.get_by_id(db, user_id=token_data.sub)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND, detail="User not found"
+        )
+    return user
+
+
+async def get_current_active_user(
+    current_user: User = Depends(get_current_user),
+) -> User:
+    """
+    Get current active user.
+    """
+    if not current_user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST, detail="Inactive user"
+        )
+    return current_user
+
+
+async def get_current_active_superuser(
+    current_user: User = Depends(get_current_active_user),
+) -> User:
+    """
+    Get current active superuser.
+    """
+    if not current_user.is_superuser:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions",
+        )
+    return current_user
--- a/app/api/endpoints/init.py
+++ b/app/api/endpoints/init.py
--- a/app/api/endpoints/auth.py
+++ b/app/api/endpoints/auth.py
@ -0,0 +1,98 @@
+from datetime import timedelta
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.config import settings
+from app.core.database import get_db
+from app.core.security import create_access_token
+from app.crud import user as crud_user
+from app.schemas.user import Token, User, UserCreate, UserLogin
+
+router = APIRouter()
+
+
+@router.post("/auth/register", response_model=User, status_code=status.HTTP_201_CREATED)
+async def register(user_in: UserCreate, db: AsyncSession = Depends(get_db)) -> Any:
+    """
+    Register a new user.
+    """
+    # Check if user with this email already exists
+    user = await crud_user.get_by_email(db, email=user_in.email)
+    if user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Email already registered",
+        )
+
+    # Create new user
+    user = await crud_user.create(db, obj_in=user_in)
+    return user
+
+
+@router.post("/auth/login", response_model=Token)
+async def login(
+    form_data: OAuth2PasswordRequestForm = Depends(), db: AsyncSession = Depends(get_db)
+) -> Any:
+    """
+    OAuth2 compatible token login, get an access token for future requests.
+    """
+    user = await crud_user.authenticate(
+        db, email=form_data.username, password=form_data.password
+    )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect email or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST, detail="Inactive user"
+        )
+
+    # Update last login timestamp
+    await crud_user.update_last_login(db, user=user)
+
+    # Create access token
+    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+    return {
+        "access_token": create_access_token(
+            user.id, expires_delta=access_token_expires
+        ),
+        "token_type": "bearer",
+    }
+
+
+@router.post("/auth/login/json", response_model=Token)
+async def login_json(login_data: UserLogin, db: AsyncSession = Depends(get_db)) -> Any:
+    """
+    JSON compatible login, get an access token for future requests.
+    """
+    user = await crud_user.authenticate(
+        db, email=login_data.email, password=login_data.password
+    )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect email or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST, detail="Inactive user"
+        )
+
+    # Update last login timestamp
+    await crud_user.update_last_login(db, user=user)
+
+    # Create access token
+    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
+    return {
+        "access_token": create_access_token(
+            user.id, expires_delta=access_token_expires
+        ),
+        "token_type": "bearer",
+    }
--- a/app/api/endpoints/users.py
+++ b/app/api/endpoints/users.py
@ -0,0 +1,93 @@
+from typing import Any, List
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_db
+from app.crud import user as crud_user
+from app.schemas.user import User, UserUpdate
+from app.api.deps import get_current_active_user, get_current_active_superuser
+
+router = APIRouter()
+
+
+@router.get("/users/me", response_model=User)
+async def read_user_me(
+    current_user: User = Depends(get_current_active_user),
+) -> Any:
+    """
+    Get current user information.
+    """
+    return current_user
+
+
+@router.put("/users/me", response_model=User)
+async def update_user_me(
+    user_in: UserUpdate,
+    current_user: User = Depends(get_current_active_user),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Update own user information.
+    """
+    user = await crud_user.update(db, db_obj=current_user, obj_in=user_in)
+    return user
+
+
+@router.get("/users", response_model=List[User])
+async def read_users(
+    skip: int = 0,
+    limit: int = 100,
+    current_user: User = Depends(get_current_active_superuser),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Retrieve users. Only available to superusers.
+    """
+    users = await crud_user.get_users(db, skip=skip, limit=limit)
+    return users
+
+
+@router.get("/users/{user_id}", response_model=User)
+async def read_user_by_id(
+    user_id: str,
+    current_user: User = Depends(get_current_active_user),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Get a specific user by id.
+    """
+    user = await crud_user.get_by_id(db, user_id=user_id)
+    if user == current_user:
+        return user
+    if not current_user.is_superuser:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Not enough permissions to access this resource",
+        )
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+    return user
+
+
+@router.put("/users/{user_id}", response_model=User)
+async def update_user(
+    user_id: str,
+    user_in: UserUpdate,
+    current_user: User = Depends(get_current_active_superuser),
+    db: AsyncSession = Depends(get_db),
+) -> Any:
+    """
+    Update a user. Only available to superusers.
+    """
+    user = await crud_user.get_by_id(db, user_id=user_id)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+    user = await crud_user.update(db, db_obj=user, obj_in=user_in)
+    return user
--- a/app/core/init.py
+++ b/app/core/init.py
--- a/app/core/config.py
+++ b/app/core/config.py
@ -0,0 +1,47 @@
+from pathlib import Path
+from typing import List, Optional, Union
+
+from pydantic import AnyHttpUrl, EmailStr, validator
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    # Base Settings
+    PROJECT_NAME: str = "User Authentication Service"
+    API_V1_STR: str = "/api/v1"
+
+    # Database Settings
+    DB_DIR: Path = Path("/app") / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+
+    # JWT Settings
+    SECRET_KEY: str = "CHANGE_THIS_TO_A_SECURE_SECRET_IN_PRODUCTION"
+    ALGORITHM: str = "HS256"
+    # 60 minutes * 24 hours * 7 days = 7 days
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60 * 24 * 7
+
+    # CORS Settings
+    BACKEND_CORS_ORIGINS: List[Union[str, AnyHttpUrl]] = ["*"]
+
+    @validator("BACKEND_CORS_ORIGINS", pre=True)
+    def assemble_cors_origins(cls, v: Union[str, List[str]]) -> Union[List[str], str]:
+        if isinstance(v, str) and not v.startswith("["):
+            return [i.strip() for i in v.split(",")]
+        elif isinstance(v, (list, str)):
+            return v
+        raise ValueError(v)
+
+    # Email Settings
+    EMAILS_FROM_EMAIL: Optional[EmailStr] = None
+    EMAILS_FROM_NAME: Optional[str] = None
+
+    class Config:
+        case_sensitive = True
+        env_file = ".env"
+
+
+# Create settings object
+settings = Settings()
+
+# Ensure DB directory exists
+settings.DB_DIR.mkdir(parents=True, exist_ok=True)
--- a/app/core/database.py
+++ b/app/core/database.py
@ -0,0 +1,54 @@
+from pathlib import Path
+from typing import AsyncGenerator
+
+from sqlalchemy import create_engine
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+
+# Ensure DB directory exists
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+# Create SQLite URL (with URI flag for foreign key support)
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+# Create engine for synchronous operations (like migrations)
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
+)
+
+# For async operations, we need to use a different driver
+ASYNC_SQLALCHEMY_DATABASE_URL = f"sqlite+aiosqlite:///{DB_DIR}/db.sqlite"
+async_engine = create_async_engine(
+    ASYNC_SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
+)
+
+# Create session factories
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+AsyncSessionLocal = sessionmaker(
+    autocommit=False,
+    autoflush=False,
+    bind=async_engine,
+    class_=AsyncSession,
+)
+
+# Create a base class for declarative models
+Base = declarative_base()
+
+
+# Dependency function for getting a database session
+async def get_db() -> AsyncGenerator[AsyncSession, None]:
+    """
+    Dependency function that yields an async database session.
+    """
+    async with AsyncSessionLocal() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+        finally:
+            await session.close()
--- a/app/core/errors.py
+++ b/app/core/errors.py
@ -0,0 +1,48 @@
+from typing import Any, Dict, Optional
+
+from fastapi import HTTPException, status
+
+
+class AuthError(HTTPException):
+    """Authentication error."""
+
+    def __init__(
+        self,
+        detail: str = "Authentication error",
+        headers: Optional[Dict[str, Any]] = None,
+    ):
+        super().__init__(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail=detail,
+            headers=headers or {"WWW-Authenticate": "Bearer"},
+        )
+
+
+class ForbiddenError(HTTPException):
+    """Permission denied error."""
+
+    def __init__(self, detail: str = "Permission denied"):
+        super().__init__(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail=detail,
+        )
+
+
+class NotFoundError(HTTPException):
+    """Resource not found error."""
+
+    def __init__(self, detail: str = "Resource not found"):
+        super().__init__(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail=detail,
+        )
+
+
+class BadRequestError(HTTPException):
+    """Bad request error."""
+
+    def __init__(self, detail: str = "Bad request"):
+        super().__init__(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=detail,
+        )
--- a/app/core/health.py
+++ b/app/core/health.py
@ -0,0 +1,15 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_db
+from app.models.health import HealthCheck
+
+health_router = APIRouter()
+
+
+@health_router.get("/health", response_model=HealthCheck, tags=["health"])
+async def health(db: AsyncSession = Depends(get_db)):
+    """
+    Health check endpoint to verify API is running properly.
+    """
+    return {"status": "ok", "database": "connected", "api_version": "v1"}
--- a/app/core/security.py
+++ b/app/core/security.py
@ -0,0 +1,66 @@
+from datetime import datetime, timedelta
+from typing import Any, Optional, Union
+
+from jose import jwt
+from passlib.context import CryptContext
+
+from app.core.config import settings
+
+# Password hashing context
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+# Token related functions
+def create_access_token(
+    subject: Union[str, Any], expires_delta: Optional[timedelta] = None
+) -> str:
+    """
+    Create a JWT access token.
+
+    Args:
+        subject: The subject to encode in the JWT (typically user ID)
+        expires_delta: Optional timedelta for token expiration
+
+    Returns:
+        JWT token as string
+    """
+    if expires_delta:
+        expire = datetime.utcnow() + expires_delta
+    else:
+        expire = datetime.utcnow() + timedelta(
+            minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+        )
+
+    to_encode = {"exp": expire, "sub": str(subject)}
+    encoded_jwt = jwt.encode(
+        to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM
+    )
+    return encoded_jwt
+
+
+# Password related functions
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """
+    Verify a plain password against a hashed password.
+
+    Args:
+        plain_password: The plain text password
+        hashed_password: The hashed password to compare against
+
+    Returns:
+        True if the password matches, False otherwise
+    """
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def get_password_hash(password: str) -> str:
+    """
+    Generate a password hash from a plain password.
+
+    Args:
+        password: The plain text password to hash
+
+    Returns:
+        Hashed password string
+    """
+    return pwd_context.hash(password)
--- a/app/crud/init.py
+++ b/app/crud/init.py
--- a/app/crud/user.py
+++ b/app/crud/user.py
@ -0,0 +1,113 @@
+from datetime import datetime
+from typing import Any, Dict, List, Optional, Union
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.security import get_password_hash, verify_password
+from app.models.user import User
+from app.schemas.user import UserCreate, UserUpdate
+
+
+async def get_by_id(db: AsyncSession, user_id: str) -> Optional[User]:
+    """
+    Get a user by ID.
+    """
+    result = await db.execute(select(User).filter(User.id == user_id))
+    return result.scalars().first()
+
+
+async def get_by_email(db: AsyncSession, email: str) -> Optional[User]:
+    """
+    Get a user by email.
+    """
+    result = await db.execute(select(User).filter(User.email == email))
+    return result.scalars().first()
+
+
+async def get_users(db: AsyncSession, skip: int = 0, limit: int = 100) -> List[User]:
+    """
+    Get a list of users with pagination.
+    """
+    result = await db.execute(select(User).offset(skip).limit(limit))
+    return result.scalars().all()
+
+
+async def create(db: AsyncSession, *, obj_in: UserCreate) -> User:
+    """
+    Create a new user.
+    """
+    db_obj = User(
+        email=obj_in.email,
+        hashed_password=get_password_hash(obj_in.password),
+        full_name=obj_in.full_name,
+        is_active=True,
+        is_superuser=False,
+        email_verified=False,
+    )
+    db.add(db_obj)
+    await db.commit()
+    await db.refresh(db_obj)
+    return db_obj
+
+
+async def update(
+    db: AsyncSession, *, db_obj: User, obj_in: Union[UserUpdate, Dict[str, Any]]
+) -> User:
+    """
+    Update a user.
+    """
+    if isinstance(obj_in, dict):
+        update_data = obj_in
+    else:
+        update_data = obj_in.dict(exclude_unset=True)
+
+    if "password" in update_data and update_data["password"]:
+        hashed_password = get_password_hash(update_data["password"])
+        del update_data["password"]
+        update_data["hashed_password"] = hashed_password
+
+    for field in update_data:
+        if hasattr(db_obj, field):
+            setattr(db_obj, field, update_data[field])
+
+    db.add(db_obj)
+    await db.commit()
+    await db.refresh(db_obj)
+    return db_obj
+
+
+async def remove(db: AsyncSession, *, id: str) -> Optional[User]:
+    """
+    Delete a user.
+    """
+    user = await get_by_id(db, id)
+    if user:
+        await db.delete(user)
+        await db.commit()
+    return user
+
+
+async def authenticate(
+    db: AsyncSession, *, email: str, password: str
+) -> Optional[User]:
+    """
+    Authenticate a user by email and password.
+    """
+    user = await get_by_email(db, email=email)
+    if not user:
+        return None
+    if not verify_password(password, user.hashed_password):
+        return None
+    return user
+
+
+async def update_last_login(db: AsyncSession, *, user: User) -> User:
+    """
+    Update the last login timestamp for a user.
+    """
+    user.last_login = datetime.utcnow()
+    db.add(user)
+    await db.commit()
+    await db.refresh(user)
+    return user
--- a/app/models/init.py
+++ b/app/models/init.py
--- a/app/models/health.py
+++ b/app/models/health.py
@ -0,0 +1,11 @@
+from pydantic import BaseModel
+
+
+class HealthCheck(BaseModel):
+    """
+    Health check response model.
+    """
+
+    status: str
+    database: str
+    api_version: str
--- a/app/models/user.py
+++ b/app/models/user.py
@ -0,0 +1,36 @@
+import uuid
+
+from sqlalchemy import Boolean, Column, DateTime, String
+from sqlalchemy.sql import func
+
+from app.core.database import Base
+
+
+class User(Base):
+    """
+    User model for authentication and user management.
+    """
+
+    __tablename__ = "users"
+
+    # Primary key
+    id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+
+    # Auth fields
+    email = Column(String, unique=True, index=True, nullable=False)
+    hashed_password = Column(String, nullable=False)
+
+    # User details
+    full_name = Column(String, nullable=True)
+
+    # Status fields
+    is_active = Column(Boolean, default=True, nullable=False)
+    is_superuser = Column(Boolean, default=False, nullable=False)
+    email_verified = Column(Boolean, default=False, nullable=False)
+
+    # Timestamps
+    created_at = Column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    last_login = Column(DateTime(timezone=True), nullable=True)
--- a/app/routers/init.py
+++ b/app/routers/init.py
--- a/app/schemas/init.py
+++ b/app/schemas/init.py
--- a/app/schemas/user.py
+++ b/app/schemas/user.py
@ -0,0 +1,59 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel, EmailStr, Field
+
+
+# Shared properties
+class UserBase(BaseModel):
+    email: Optional[EmailStr] = None
+    is_active: Optional[bool] = True
+    is_superuser: Optional[bool] = False
+    full_name: Optional[str] = None
+
+
+# Properties to receive on user creation
+class UserCreate(BaseModel):
+    email: EmailStr
+    password: str = Field(..., min_length=8)
+    full_name: Optional[str] = None
+
+
+# Properties to receive on user update
+class UserUpdate(UserBase):
+    password: Optional[str] = Field(None, min_length=8)
+
+
+# Properties to return to client
+class User(UserBase):
+    id: str
+    email_verified: bool
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+    last_login: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+# Properties to return to admin users
+class UserAdminRead(User):
+    pass
+
+
+# Properties for user login
+class UserLogin(BaseModel):
+    email: EmailStr
+    password: str
+
+
+# Token response schema
+class Token(BaseModel):
+    access_token: str
+    token_type: str = "bearer"
+
+
+# Token payload schema
+class TokenPayload(BaseModel):
+    sub: str
+    exp: datetime
--- a/app/utils/init.py
+++ b/app/utils/init.py
--- a/main.py
+++ b/main.py
@ -0,0 +1,48 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.openapi.utils import get_openapi
+
+from app.api.api import api_router
+from app.core.config import settings
+from app.core.health import health_router
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    description="User Authentication Service API",
+    version="0.1.0",
+    openapi_url="/openapi.json",
+)
+
+# Set up CORS
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers
+app.include_router(health_router)
+app.include_router(api_router)
+
+
+def custom_openapi():
+    if app.openapi_schema:
+        return app.openapi_schema
+    openapi_schema = get_openapi(
+        title=app.title,
+        version=app.version,
+        description=app.description,
+        routes=app.routes,
+    )
+    app.openapi_schema = openapi_schema
+    return app.openapi_schema
+
+
+app.openapi = custom_openapi
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)
--- a/migrations/init.py
+++ b/migrations/init.py
--- a/migrations/env.py
+++ b/migrations/env.py
@ -0,0 +1,62 @@
+from logging.config import fileConfig
+
+from alembic import context
+from app.core.database import Base
+
+# Import all models so they are registered with SQLAlchemy
+import app.models.user  # noqa
+from sqlalchemy import engine_from_config, pool
+
+# This is the Alembic Config object
+config = context.config
+
+# Interpret the config file for Python logging.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# Add your model's MetaData here
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode."""
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        # For SQLite, use batch mode for table alterations
+        render_as_batch=True,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode."""
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        is_sqlite = connection.dialect.name == "sqlite"
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            # For SQLite, use batch mode for table alterations
+            render_as_batch=is_sqlite,
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()
--- a/migrations/script.py.mako
+++ b/migrations/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():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}
--- a/migrations/versions/initial_migration.py
+++ b/migrations/versions/initial_migration.py
@ -0,0 +1,51 @@
+"""Initial migration
+
+Revision ID: 001
+Revises:
+Create Date: 2023-10-01
+
+"""
+
+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():
+    # Create users table
+    op.create_table(
+        "users",
+        sa.Column("id", sa.String(36), primary_key=True),
+        sa.Column("email", sa.String(), nullable=False),
+        sa.Column("hashed_password", sa.String(), nullable=False),
+        sa.Column("full_name", sa.String(), nullable=True),
+        sa.Column("is_active", sa.Boolean(), nullable=False, default=True),
+        sa.Column("is_superuser", sa.Boolean(), nullable=False, default=False),
+        sa.Column("email_verified", sa.Boolean(), nullable=False, default=False),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
+        ),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("last_login", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+    )
+
+    # Create indexes
+    op.create_index(op.f("ix_users_email"), "users", ["email"], unique=True)
+
+
+def downgrade():
+    # Drop indexes
+    op.drop_index(op.f("ix_users_email"), table_name="users")
+
+    # Drop tables
+    op.drop_table("users")
--- a/requirements.txt
+++ b/requirements.txt
@ -0,0 +1,11 @@
+fastapi>=0.103.1
+uvicorn>=0.23.2
+sqlalchemy>=2.0.20
+alembic>=1.12.0
+pydantic>=2.3.0
+pydantic-settings>=2.0.3
+python-jose[cryptography]>=3.3.0
+passlib[bcrypt]>=1.7.4
+python-multipart>=0.0.6
+email-validator>=2.0.0
+ruff>=0.0.290