Create comprehensive Task Manager API with FastAPI

- Add user authentication with JWT tokens - Implement task CRUD operations with status and priority - Set up SQLite database with SQLAlchemy ORM - Create Alembic migrations for database schema - Add comprehensive API documentation - Include health check endpoint and CORS configuration - Structure codebase with proper separation of concerns
2025-06-20 19:35:55 +00:00 · 2025-06-20 19:35:55 +00:00 · c9baaa994e
commit c9baaa994e
parent 81d5ad9c9d
28 changed files with 938 additions and 2 deletions
--- a/README.md
+++ b/README.md
@ -1,3 +1,175 @@
-# FastAPI Application
+# Task Manager API

-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A comprehensive Task Manager API built with FastAPI, featuring user authentication, task management, and SQLite database integration.
+
+## Features
+
+- User registration and authentication with JWT tokens
+- Task CRUD operations (Create, Read, Update, Delete)
+- Task filtering by status and priority
+- User profile management
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- API documentation with Swagger UI
+- Health check endpoint
+- CORS enabled for all origins
+
+## Project Structure
+
+```
+├── main.py                 # FastAPI application entry point
+├── requirements.txt        # Python dependencies
+├── alembic.ini            # Alembic configuration
+├── alembic/               # Database migrations
+├── app/
+│   ├── api/               # API route handlers
+│   │   ├── auth.py        # Authentication endpoints
+│   │   ├── tasks.py       # Task management endpoints
+│   │   └── users.py       # User management endpoints
+│   ├── core/              # Core application logic
+│   │   ├── auth.py        # Authentication dependencies
+│   │   ├── config.py      # Application configuration
+│   │   └── security.py    # Security utilities
+│   ├── db/                # Database configuration
+│   │   ├── base.py        # SQLAlchemy base class
+│   │   └── session.py     # Database session management
+│   ├── models/            # SQLAlchemy models
+│   │   ├── task.py        # Task model
+│   │   └── user.py        # User model
+│   ├── schemas/           # Pydantic schemas
+│   │   ├── task.py        # Task schemas
+│   │   └── user.py        # User schemas
+│   └── services/          # Business logic layer
+│       ├── task.py        # Task service
+│       └── user.py        # User service
+└── storage/
+    └── db/                # SQLite database storage
+```
+
+## Installation
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+2. Run database migrations:
+```bash
+alembic upgrade head
+```
+
+3. Start the application:
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at `http://localhost:8000`
+
+## Environment Variables
+
+Set the following environment variables for production:
+
+- `SECRET_KEY`: Secret key for JWT token signing (default: "your-secret-key-here")
+
+Example:
+```bash
+export SECRET_KEY="your-super-secret-key-here"
+```
+
+## API Endpoints
+
+### Authentication
+- `POST /auth/register` - Register a new user
+- `POST /auth/login` - Login and get access token
+
+### Tasks
+- `GET /tasks/` - Get all tasks for authenticated user
+- `POST /tasks/` - Create a new task
+- `GET /tasks/{task_id}` - Get a specific task
+- `PUT /tasks/{task_id}` - Update a task
+- `DELETE /tasks/{task_id}` - Delete a task
+
+### Users
+- `GET /users/me` - Get current user profile
+- `PUT /users/me` - Update current user profile
+
+### System
+- `GET /` - API information
+- `GET /health` - Health check endpoint
+
+## API Documentation
+
+- Swagger UI: `http://localhost:8000/docs`
+- ReDoc: `http://localhost:8000/redoc`
+- OpenAPI JSON: `http://localhost:8000/openapi.json`
+
+## Task Management
+
+### Task Status Options
+- `pending` - Task is pending
+- `in_progress` - Task is in progress
+- `completed` - Task is completed
+- `cancelled` - Task is cancelled
+
+### Task Priority Options
+- `low` - Low priority
+- `medium` - Medium priority
+- `high` - High priority
+- `urgent` - Urgent priority
+
+## Authentication
+
+The API uses JWT (JSON Web Tokens) for authentication. After registration or login, include the token in the Authorization header:
+
+```
+Authorization: Bearer <your-jwt-token>
+```
+
+## Database
+
+The application uses SQLite as the database with the following features:
+- Database file stored at `/app/storage/db/db.sqlite`
+- Automatic table creation on startup
+- Database migrations managed by Alembic
+- Relationships between users and tasks
+
+## Development
+
+### Running Tests
+To run tests (when available):
+```bash
+pytest
+```
+
+### Code Formatting
+The project uses Ruff for code formatting and linting:
+```bash
+ruff check .
+ruff format .
+```
+
+### Database Operations
+Create a new migration:
+```bash
+alembic revision --autogenerate -m "description"
+```
+
+Apply migrations:
+```bash
+alembic upgrade head
+```
+
+## Health Check
+
+The application provides a health check endpoint at `/health` that returns:
+```json
+{
+  "status": "healthy",
+  "service": "Task Manager API",
+  "version": "1.0.0"
+}
+```
+
+## License
+
+This project is generated by BackendIM, the AI-powered backend generation platform.
--- a/alembic.ini
+++ b/alembic.ini
@ -0,0 +1,41 @@
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+version_path_separator = os
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[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
--- a/alembic/env.py
+++ b/alembic/env.py
@ -0,0 +1,49 @@
+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(__file__)))
+
+from app.db.base import Base
+
+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()
--- a/alembic/script.py.mako
+++ b/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"}
--- a/alembic/versions/001_initial_migration.py
+++ b/alembic/versions/001_initial_migration.py
@ -0,0 +1,79 @@
+"""Initial migration
+
+Revision ID: 001
+Revises:
+Create Date: 2024-01-01 12:00:00.000000
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = "001"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "users",
+        sa.Column("id", sa.Integer(), nullable=False),
+        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=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_users_email"), "users", ["email"], unique=True)
+    op.create_index(op.f("ix_users_id"), "users", ["id"], unique=False)
+
+    op.create_table(
+        "tasks",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("title", sa.String(), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column(
+            "status",
+            sa.Enum(
+                "PENDING", "IN_PROGRESS", "COMPLETED", "CANCELLED", name="taskstatus"
+            ),
+            nullable=True,
+        ),
+        sa.Column(
+            "priority",
+            sa.Enum("LOW", "MEDIUM", "HIGH", "URGENT", name="taskpriority"),
+            nullable=True,
+        ),
+        sa.Column("is_completed", sa.Boolean(), nullable=True),
+        sa.Column("due_date", sa.DateTime(timezone=True), 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.Column("owner_id", sa.Integer(), nullable=False),
+        sa.ForeignKeyConstraint(
+            ["owner_id"],
+            ["users.id"],
+        ),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_tasks_id"), "tasks", ["id"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_tasks_id"), table_name="tasks")
+    op.drop_table("tasks")
+    op.drop_index(op.f("ix_users_id"), table_name="users")
+    op.drop_index(op.f("ix_users_email"), table_name="users")
+    op.drop_table("users")
--- a/app/init.py
+++ b/app/init.py
--- a/app/api/init.py
+++ b/app/api/init.py
--- a/app/api/auth.py
+++ b/app/api/auth.py
@ -0,0 +1,37 @@
+from datetime import timedelta
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from sqlalchemy.orm import Session
+from app.db.session import get_db
+from app.schemas.user import UserCreate, User, Token
+from app.services.user import create_user, authenticate_user, get_user_by_email
+from app.core.security import create_access_token
+from app.core.config import settings
+
+router = APIRouter()
+
+
+@router.post("/register", response_model=User)
+def register(user: UserCreate, db: Session = Depends(get_db)):
+    db_user = get_user_by_email(db, email=user.email)
+    if db_user:
+        raise HTTPException(status_code=400, detail="Email already registered")
+    return create_user(db=db, user=user)
+
+
+@router.post("/login", response_model=Token)
+def login(
+    form_data: OAuth2PasswordRequestForm = Depends(), db: Session = Depends(get_db)
+):
+    user = authenticate_user(db, form_data.username, form_data.password)
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect email or password",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+    access_token_expires = timedelta(minutes=settings.access_token_expire_minutes)
+    access_token = create_access_token(
+        data={"sub": user.email}, expires_delta=access_token_expires
+    )
+    return {"access_token": access_token, "token_type": "bearer"}
--- a/app/api/tasks.py
+++ b/app/api/tasks.py
@ -0,0 +1,79 @@
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from typing import List
+from app.db.session import get_db
+from app.schemas.task import Task, TaskCreate, TaskUpdate
+from app.services.task import (
+    get_tasks_by_user,
+    get_task_by_id,
+    create_task,
+    update_task,
+    delete_task,
+    get_tasks_by_status,
+)
+from app.core.auth import get_current_active_user
+from app.models.user import User
+from app.models.task import TaskStatus
+
+router = APIRouter()
+
+
+@router.get("/", response_model=List[Task])
+def read_tasks(
+    skip: int = 0,
+    limit: int = 100,
+    status: TaskStatus = None,
+    current_user: User = Depends(get_current_active_user),
+    db: Session = Depends(get_db),
+):
+    if status:
+        return get_tasks_by_status(db, user_id=current_user.id, status=status)
+    return get_tasks_by_user(db, user_id=current_user.id, skip=skip, limit=limit)
+
+
+@router.post("/", response_model=Task)
+def create_new_task(
+    task: TaskCreate,
+    current_user: User = Depends(get_current_active_user),
+    db: Session = Depends(get_db),
+):
+    return create_task(db, task=task, user_id=current_user.id)
+
+
+@router.get("/{task_id}", response_model=Task)
+def read_task(
+    task_id: int,
+    current_user: User = Depends(get_current_active_user),
+    db: Session = Depends(get_db),
+):
+    db_task = get_task_by_id(db, task_id=task_id, user_id=current_user.id)
+    if db_task is None:
+        raise HTTPException(status_code=404, detail="Task not found")
+    return db_task
+
+
+@router.put("/{task_id}", response_model=Task)
+def update_existing_task(
+    task_id: int,
+    task: TaskUpdate,
+    current_user: User = Depends(get_current_active_user),
+    db: Session = Depends(get_db),
+):
+    db_task = update_task(
+        db, task_id=task_id, task_update=task, user_id=current_user.id
+    )
+    if db_task is None:
+        raise HTTPException(status_code=404, detail="Task not found")
+    return db_task
+
+
+@router.delete("/{task_id}")
+def delete_existing_task(
+    task_id: int,
+    current_user: User = Depends(get_current_active_user),
+    db: Session = Depends(get_db),
+):
+    success = delete_task(db, task_id=task_id, user_id=current_user.id)
+    if not success:
+        raise HTTPException(status_code=404, detail="Task not found")
+    return {"message": "Task deleted successfully"}
--- a/app/api/users.py
+++ b/app/api/users.py
@ -0,0 +1,23 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+from app.db.session import get_db
+from app.schemas.user import User, UserUpdate
+from app.services.user import update_user
+from app.core.auth import get_current_active_user
+from app.models.user import User as UserModel
+
+router = APIRouter()
+
+
+@router.get("/me", response_model=User)
+def read_current_user(current_user: UserModel = Depends(get_current_active_user)):
+    return current_user
+
+
+@router.put("/me", response_model=User)
+def update_current_user(
+    user_update: UserUpdate,
+    current_user: UserModel = Depends(get_current_active_user),
+    db: Session = Depends(get_db),
+):
+    return update_user(db, user_id=current_user.id, user_update=user_update)
--- a/app/core/init.py
+++ b/app/core/init.py
--- a/app/core/auth.py
+++ b/app/core/auth.py
@ -0,0 +1,37 @@
+from fastapi import Depends, HTTPException, status
+from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
+from sqlalchemy.orm import Session
+from app.db.session import get_db
+from app.core.security import verify_token
+from app.services.user import get_user_by_email
+from app.models.user import User
+
+security = HTTPBearer()
+
+
+def get_current_user(
+    credentials: HTTPAuthorizationCredentials = Depends(security),
+    db: Session = Depends(get_db),
+) -> User:
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Could not validate credentials",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+
+    token = credentials.credentials
+    email = verify_token(token)
+    if email is None:
+        raise credentials_exception
+
+    user = get_user_by_email(db, email=email)
+    if user is None:
+        raise credentials_exception
+
+    return user
+
+
+def get_current_active_user(current_user: User = Depends(get_current_user)) -> User:
+    if not current_user.is_active:
+        raise HTTPException(status_code=400, detail="Inactive user")
+    return current_user
--- a/app/core/config.py
+++ b/app/core/config.py
@ -0,0 +1,16 @@
+import os
+from pydantic import BaseSettings
+
+
+class Settings(BaseSettings):
+    secret_key: str = os.getenv("SECRET_KEY", "your-secret-key-here")
+    algorithm: str = "HS256"
+    access_token_expire_minutes: int = 30
+    app_name: str = "Task Manager API"
+    app_version: str = "1.0.0"
+
+    class Config:
+        env_file = ".env"
+
+
+settings = Settings()
--- a/app/core/security.py
+++ b/app/core/security.py
@ -0,0 +1,41 @@
+from datetime import datetime, timedelta
+from typing import Optional
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+from app.core.config import settings
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def get_password_hash(password: str) -> str:
+    return pwd_context.hash(password)
+
+
+def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
+    to_encode = data.copy()
+    if expires_delta:
+        expire = datetime.utcnow() + expires_delta
+    else:
+        expire = datetime.utcnow() + timedelta(minutes=15)
+    to_encode.update({"exp": expire})
+    encoded_jwt = jwt.encode(
+        to_encode, settings.secret_key, algorithm=settings.algorithm
+    )
+    return encoded_jwt
+
+
+def verify_token(token: str):
+    try:
+        payload = jwt.decode(
+            token, settings.secret_key, algorithms=[settings.algorithm]
+        )
+        email: str = payload.get("sub")
+        if email is None:
+            return None
+        return email
+    except JWTError:
+        return None
--- a/app/db/init.py
+++ b/app/db/init.py
--- a/app/db/base.py
+++ b/app/db/base.py
@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
--- a/app/db/session.py
+++ b/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()
--- a/app/models/init.py
+++ b/app/models/init.py
--- a/app/models/task.py
+++ b/app/models/task.py
@ -0,0 +1,45 @@
+from sqlalchemy import (
+    Column,
+    Integer,
+    String,
+    Text,
+    Boolean,
+    DateTime,
+    ForeignKey,
+    Enum,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.db.base import Base
+import enum
+
+
+class TaskStatus(enum.Enum):
+    PENDING = "pending"
+    IN_PROGRESS = "in_progress"
+    COMPLETED = "completed"
+    CANCELLED = "cancelled"
+
+
+class TaskPriority(enum.Enum):
+    LOW = "low"
+    MEDIUM = "medium"
+    HIGH = "high"
+    URGENT = "urgent"
+
+
+class Task(Base):
+    __tablename__ = "tasks"
+
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String, nullable=False)
+    description = Column(Text, nullable=True)
+    status = Column(Enum(TaskStatus), default=TaskStatus.PENDING)
+    priority = Column(Enum(TaskPriority), default=TaskPriority.MEDIUM)
+    is_completed = Column(Boolean, default=False)
+    due_date = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    owner_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+
+    owner = relationship("User", back_populates="tasks")
--- a/app/models/user.py
+++ b/app/models/user.py
@ -0,0 +1,18 @@
+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+    email = Column(String, unique=True, index=True, nullable=False)
+    hashed_password = Column(String, nullable=False)
+    full_name = Column(String, nullable=True)
+    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())
+
+    tasks = relationship("Task", back_populates="owner")
--- a/app/schemas/init.py
+++ b/app/schemas/init.py
--- a/app/schemas/task.py
+++ b/app/schemas/task.py
@ -0,0 +1,36 @@
+from pydantic import BaseModel
+from typing import Optional
+from datetime import datetime
+from app.models.task import TaskStatus, TaskPriority
+
+
+class TaskBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    status: TaskStatus = TaskStatus.PENDING
+    priority: TaskPriority = TaskPriority.MEDIUM
+    due_date: Optional[datetime] = None
+
+
+class TaskCreate(TaskBase):
+    pass
+
+
+class TaskUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    status: Optional[TaskStatus] = None
+    priority: Optional[TaskPriority] = None
+    due_date: Optional[datetime] = None
+    is_completed: Optional[bool] = None
+
+
+class Task(TaskBase):
+    id: int
+    is_completed: bool
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+    owner_id: int
+
+    class Config:
+        from_attributes = True
--- a/app/schemas/user.py
+++ b/app/schemas/user.py
@ -0,0 +1,42 @@
+from pydantic import BaseModel, EmailStr
+from typing import Optional
+from datetime import datetime
+
+
+class UserBase(BaseModel):
+    email: EmailStr
+    full_name: Optional[str] = None
+
+
+class UserCreate(UserBase):
+    password: str
+
+
+class UserUpdate(BaseModel):
+    email: Optional[EmailStr] = None
+    full_name: Optional[str] = None
+    password: Optional[str] = None
+
+
+class User(UserBase):
+    id: int
+    is_active: bool
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True
+
+
+class UserLogin(BaseModel):
+    email: EmailStr
+    password: str
+
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str
+
+
+class TokenData(BaseModel):
+    email: Optional[str] = None
--- a/app/services/init.py
+++ b/app/services/init.py
--- a/app/services/task.py
+++ b/app/services/task.py
@ -0,0 +1,64 @@
+from sqlalchemy.orm import Session
+from app.models.task import Task, TaskStatus
+from app.schemas.task import TaskCreate, TaskUpdate
+from typing import List, Optional
+
+
+def get_tasks_by_user(
+    db: Session, user_id: int, skip: int = 0, limit: int = 100
+) -> List[Task]:
+    return (
+        db.query(Task).filter(Task.owner_id == user_id).offset(skip).limit(limit).all()
+    )
+
+
+def get_task_by_id(db: Session, task_id: int, user_id: int) -> Optional[Task]:
+    return db.query(Task).filter(Task.id == task_id, Task.owner_id == user_id).first()
+
+
+def create_task(db: Session, task: TaskCreate, user_id: int) -> Task:
+    db_task = Task(**task.dict(), owner_id=user_id)
+    db.add(db_task)
+    db.commit()
+    db.refresh(db_task)
+    return db_task
+
+
+def update_task(
+    db: Session, task_id: int, task_update: TaskUpdate, user_id: int
+) -> Optional[Task]:
+    db_task = get_task_by_id(db, task_id, user_id)
+    if not db_task:
+        return None
+
+    update_data = task_update.dict(exclude_unset=True)
+
+    if "status" in update_data:
+        if update_data["status"] == TaskStatus.COMPLETED:
+            update_data["is_completed"] = True
+        elif update_data["status"] != TaskStatus.COMPLETED and db_task.is_completed:
+            update_data["is_completed"] = False
+
+    if "is_completed" in update_data and update_data["is_completed"]:
+        update_data["status"] = TaskStatus.COMPLETED
+
+    for field, value in update_data.items():
+        setattr(db_task, field, value)
+
+    db.commit()
+    db.refresh(db_task)
+    return db_task
+
+
+def delete_task(db: Session, task_id: int, user_id: int) -> bool:
+    db_task = get_task_by_id(db, task_id, user_id)
+    if not db_task:
+        return False
+
+    db.delete(db_task)
+    db.commit()
+    return True
+
+
+def get_tasks_by_status(db: Session, user_id: int, status: TaskStatus) -> List[Task]:
+    return db.query(Task).filter(Task.owner_id == user_id, Task.status == status).all()
--- a/app/services/user.py
+++ b/app/services/user.py
@ -0,0 +1,53 @@
+from sqlalchemy.orm import Session
+from app.models.user import User
+from app.schemas.user import UserCreate, UserUpdate
+from app.core.security import get_password_hash, verify_password
+from typing import Optional
+
+
+def get_user_by_email(db: Session, email: str) -> Optional[User]:
+    return db.query(User).filter(User.email == email).first()
+
+
+def get_user_by_id(db: Session, user_id: int) -> Optional[User]:
+    return db.query(User).filter(User.id == user_id).first()
+
+
+def create_user(db: Session, user: UserCreate) -> User:
+    hashed_password = get_password_hash(user.password)
+    db_user = User(
+        email=user.email,
+        hashed_password=hashed_password,
+        full_name=user.full_name,
+    )
+    db.add(db_user)
+    db.commit()
+    db.refresh(db_user)
+    return db_user
+
+
+def authenticate_user(db: Session, email: str, password: str) -> Optional[User]:
+    user = get_user_by_email(db, email)
+    if not user:
+        return None
+    if not verify_password(password, user.hashed_password):
+        return None
+    return user
+
+
+def update_user(db: Session, user_id: int, user_update: UserUpdate) -> Optional[User]:
+    db_user = get_user_by_id(db, user_id)
+    if not db_user:
+        return None
+
+    update_data = user_update.dict(exclude_unset=True)
+
+    if "password" in update_data:
+        update_data["hashed_password"] = get_password_hash(update_data.pop("password"))
+
+    for field, value in update_data.items():
+        setattr(db_user, field, value)
+
+    db.commit()
+    db.refresh(db_user)
+    return db_user
--- a/main.py
+++ b/main.py
@ -0,0 +1,46 @@
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from app.api import auth, tasks, users
+from app.core.config import settings
+from app.db.session import engine
+from app.db.base import Base
+
+app = FastAPI(
+    title=settings.app_name,
+    version=settings.app_version,
+    description="A comprehensive Task Manager API built with FastAPI",
+    openapi_url="/openapi.json",
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+Base.metadata.create_all(bind=engine)
+
+app.include_router(auth.router, prefix="/auth", tags=["authentication"])
+app.include_router(tasks.router, prefix="/tasks", tags=["tasks"])
+app.include_router(users.router, prefix="/users", tags=["users"])
+
+
+@app.get("/")
+def read_root():
+    return {
+        "title": settings.app_name,
+        "version": settings.app_version,
+        "documentation": "/docs",
+        "health_check": "/health",
+    }
+
+
+@app.get("/health")
+def health_check():
+    return {
+        "status": "healthy",
+        "service": settings.app_name,
+        "version": settings.app_version,
+    }
--- a/requirements.txt
+++ b/requirements.txt
@ -0,0 +1,9 @@
+fastapi==0.104.1
+uvicorn==0.24.0
+sqlalchemy==2.0.23
+alembic==1.12.1
+pydantic==2.5.0
+python-jose[cryptography]==3.3.0
+passlib[bcrypt]==1.7.4
+python-multipart==0.0.6
+ruff==0.1.6