Create FastAPI REST API service

- Add FastAPI application with CORS support
- Implement SQLite database with SQLAlchemy
- Create Item model with CRUD operations
- Setup Alembic for database migrations
- Add comprehensive API endpoints for Items
- Include health check endpoint
- Update README with documentation

README.md

@@ -1,3 +1,59 @@
-# FastAPI Application
+# REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A REST API service built with FastAPI and SQLite.
+
+## Features
+
+- FastAPI web framework
+- SQLite database with SQLAlchemy ORM
+- Database migrations with Alembic
+- CRUD operations for Items
+- CORS enabled for all origins
+- Health check endpoint
+- Interactive API documentation
+
+## Installation
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+## Running the Application
+
+Start the development server:
+```bash
+uvicorn main:app --reload --host 0.0.0.0 --port 8000
+```
+
+The API will be available at:
+- Main API: http://localhost:8000
+- Interactive docs: http://localhost:8000/docs
+- OpenAPI spec: http://localhost:8000/openapi.json
+- Health check: http://localhost:8000/health
+
+## API Endpoints
+
+### Items CRUD
+- `GET /items/` - List all items
+- `POST /items/` - Create a new item
+- `GET /items/{item_id}` - Get a specific item
+- `PUT /items/{item_id}` - Update a specific item
+- `DELETE /items/{item_id}` - Delete a specific item
+
+### System
+- `GET /` - API information
+- `GET /health` - Health check
+
+## Database
+
+The application uses SQLite database stored at `/app/storage/db/db.sqlite`.
+
+Database migrations are managed with Alembic. To run migrations:
+```bash
+alembic upgrade head
+```
+
+## Environment Variables
+
+No environment variables are required for basic operation.

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

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
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+
+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()

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 +1,34 @@
+"""Initial migration
+
+Revision ID: 001
+Revises: 
+Create Date: 2025-06-19 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:
+    op.create_table('items',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('name', sa.String(), nullable=True),
+        sa.Column('description', sa.String(), 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_items_id'), 'items', ['id'], unique=False)
+    op.create_index(op.f('ix_items_name'), 'items', ['name'], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f('ix_items_name'), table_name='items')
+    op.drop_index(op.f('ix_items_id'), table_name='items')
+    op.drop_table('items')

app/crud.py

@@ -0,0 +1,33 @@
+from sqlalchemy.orm import Session
+from app.models import Item
+from app.schemas import ItemCreate, ItemUpdate
+
+def get_item(db: Session, item_id: int):
+    return db.query(Item).filter(Item.id == item_id).first()
+
+def get_items(db: Session, skip: int = 0, limit: int = 100):
+    return db.query(Item).offset(skip).limit(limit).all()
+
+def create_item(db: Session, item: ItemCreate):
+    db_item = Item(**item.dict())
+    db.add(db_item)
+    db.commit()
+    db.refresh(db_item)
+    return db_item
+
+def update_item(db: Session, item_id: int, item: ItemUpdate):
+    db_item = db.query(Item).filter(Item.id == item_id).first()
+    if db_item:
+        update_data = item.dict(exclude_unset=True)
+        for key, value in update_data.items():
+            setattr(db_item, key, value)
+        db.commit()
+        db.refresh(db_item)
+    return db_item
+
+def delete_item(db: Session, item_id: int):
+    db_item = db.query(Item).filter(Item.id == item_id).first()
+    if db_item:
+        db.delete(db_item)
+        db.commit()
+    return db_item

app/db/base.py

@@ -0,0 +1,3 @@
+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.py

@@ -0,0 +1,12 @@
+from sqlalchemy import Column, Integer, String, DateTime
+from sqlalchemy.sql import func
+from app.db.base import Base
+
+class Item(Base):
+    __tablename__ = "items"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String, index=True)
+    description = Column(String)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())

app/schemas.py

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

main.py

@@ -0,0 +1,67 @@
+from fastapi import FastAPI, Depends, HTTPException
+from fastapi.middleware.cors import CORSMiddleware
+from sqlalchemy.orm import Session
+from typing import List
+
+from app.db.session import get_db, engine
+from app.db.base import Base
+from app import crud, schemas
+
+app = FastAPI(
+    title="REST API Service",
+    description="A REST API service built with FastAPI",
+    version="1.0.0",
+    openapi_url="/openapi.json"
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+Base.metadata.create_all(bind=engine)
+
+@app.get("/")
+async def root():
+    return {
+        "title": "REST API Service",
+        "documentation": "/docs",
+        "health_check": "/health"
+    }
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy", "service": "REST API Service"}
+
+@app.post("/items/", response_model=schemas.Item)
+def create_item(item: schemas.ItemCreate, db: Session = Depends(get_db)):
+    return crud.create_item(db=db, item=item)
+
+@app.get("/items/", response_model=List[schemas.Item])
+def read_items(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    items = crud.get_items(db, skip=skip, limit=limit)
+    return items
+
+@app.get("/items/{item_id}", response_model=schemas.Item)
+def read_item(item_id: int, db: Session = Depends(get_db)):
+    db_item = crud.get_item(db, item_id=item_id)
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return db_item
+
+@app.put("/items/{item_id}", response_model=schemas.Item)
+def update_item(item_id: int, item: schemas.ItemUpdate, db: Session = Depends(get_db)):
+    db_item = crud.update_item(db, item_id=item_id, item=item)
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return db_item
+
+@app.delete("/items/{item_id}")
+def delete_item(item_id: int, db: Session = Depends(get_db)):
+    db_item = crud.delete_item(db, item_id=item_id)
+    if db_item is None:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return {"message": "Item deleted successfully"}

requirements.txt

@@ -0,0 +1,5 @@
+fastapi==0.104.1
+uvicorn==0.24.0
+sqlalchemy==2.0.23
+alembic==1.12.1
+ruff==0.1.7