Create FastAPI REST API with SQLite database

- Set up project structure with FastAPI and SQLAlchemy
- Configure SQLite database with async support
- Implement CRUD endpoints for items resource
- Add health endpoint for monitoring
- Set up Alembic migrations
- Create comprehensive documentation

generated with BackendIM... (backend.im)

README.md

@@ -1,3 +1,73 @@
-# FastAPI Application
+# Quick REST API Service
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A fast, lightweight REST API service built with FastAPI and SQLite.
+
+## Features
+
+- **FastAPI Framework**: High-performance async API framework
+- **SQLite Database**: Simple, file-based database with SQLAlchemy ORM
+- **Async Support**: Full async/await pattern for high concurrency
+- **Migrations**: Database versioning with Alembic
+- **API Documentation**: Auto-generated OpenAPI docs
+- **Health Endpoint**: Monitoring endpoint at `/api/v1/health`
+- **CRUD Operations**: Complete REST API for item resources
+
+## Project Structure
+
+```
+.
+├── app
+│   ├── api
+│   │   └── v1
+│   │       ├── __init__.py 
+│   │       ├── health.py
+│   │       └── items.py
+│   ├── core
+│   │   └── config.py
+│   ├── db
+│   │   ├── __init__.py
+│   │   ├── base.py
+│   │   ├── session.py
+│   │   └── migrations/
+│   ├── models
+│   │   ├── __init__.py
+│   │   └── item.py
+│   └── schemas
+│       ├── __init__.py
+│       └── item.py
+├── alembic.ini
+├── main.py
+├── requirements.txt
+└── README.md
+```
+
+## Installation
+
+1. Clone the repository
+2. Install dependencies:
+   ```bash
+   pip install -r requirements.txt
+   ```
+
+## Running the Application
+
+Start the server with:
+
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000.
+
+API documentation is available at:
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+
+## API Endpoints
+
+- `GET /api/v1/health` - Check API health
+- `GET /api/v1/items` - List all items
+- `POST /api/v1/items` - Create a new item
+- `GET /api/v1/items/{item_id}` - Get a specific item
+- `PUT /api/v1/items/{item_id}` - Update an item
+- `DELETE /api/v1/items/{item_id}` - Delete an item

alembic.ini

@@ -0,0 +1,103 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = app/db/migrations
+
+# template used to generate migration files
+# file_template = %%(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 app/db/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:app/db/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.
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL example
+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

app/api/v1/__init__.py

@@ -0,0 +1,6 @@
+from fastapi import APIRouter
+from app.api.v1 import health, items
+
+api_router = APIRouter()
+api_router.include_router(health.router, prefix="/health", tags=["health"])
+api_router.include_router(items.router, prefix="/items", tags=["items"])

app/api/v1/health.py

@@ -0,0 +1,17 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.db.session import get_db
+
+router = APIRouter()
+
+@router.get("")
+async def health_check(db: AsyncSession = Depends(get_db)):
+    """
+    Health check endpoint to verify API and database connectivity.
+    """
+    return {
+        "status": "healthy",
+        "database": "connected",
+        "message": "API is running correctly"
+    }

app/api/v1/items.py

@@ -0,0 +1,63 @@
+from typing import List
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.future import select
+
+from app.db.session import get_db
+from app.models.item import Item
+from app.schemas.item import ItemCreate, ItemResponse, ItemUpdate
+
+router = APIRouter()
+
+@router.post("", response_model=ItemResponse, status_code=status.HTTP_201_CREATED)
+async def create_item(item_in: ItemCreate, db: AsyncSession = Depends(get_db)):
+    """Create a new item."""
+    db_item = Item(**item_in.model_dump())
+    db.add(db_item)
+    await db.commit()
+    await db.refresh(db_item)
+    return db_item
+
+@router.get("", response_model=List[ItemResponse])
+async def read_items(skip: int = 0, limit: int = 100, db: AsyncSession = Depends(get_db)):
+    """Get all items."""
+    result = await db.execute(select(Item).offset(skip).limit(limit))
+    items = result.scalars().all()
+    return items
+
+@router.get("/{item_id}", response_model=ItemResponse)
+async def read_item(item_id: int, db: AsyncSession = Depends(get_db)):
+    """Get item by ID."""
+    result = await db.execute(select(Item).filter(Item.id == item_id))
+    item = result.scalars().first()
+    if not item:
+        raise HTTPException(status_code=404, detail="Item not found")
+    return item
+
+@router.put("/{item_id}", response_model=ItemResponse)
+async def update_item(item_id: int, item_in: ItemUpdate, db: AsyncSession = Depends(get_db)):
+    """Update an item."""
+    result = await db.execute(select(Item).filter(Item.id == item_id))
+    item = result.scalars().first()
+    if not item:
+        raise HTTPException(status_code=404, detail="Item not found")
+    
+    update_data = item_in.model_dump(exclude_unset=True)
+    for key, value in update_data.items():
+        setattr(item, key, value)
+    
+    await db.commit()
+    await db.refresh(item)
+    return item
+
+@router.delete("/{item_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_item(item_id: int, db: AsyncSession = Depends(get_db)):
+    """Delete an item."""
+    result = await db.execute(select(Item).filter(Item.id == item_id))
+    item = result.scalars().first()
+    if not item:
+        raise HTTPException(status_code=404, detail="Item not found")
+    
+    await db.delete(item)
+    await db.commit()
+    return None

app/core/config.py

@@ -0,0 +1,29 @@
+from typing import List, Optional, Union
+from pathlib import Path
+from pydantic import AnyHttpUrl, validator
+from pydantic_settings import BaseSettings
+
+class Settings(BaseSettings):
+    API_V1_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Quick REST API Service"
+    
+    # CORS settings
+    BACKEND_CORS_ORIGINS: List[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)
+
+    # Database settings
+    DB_DIR = Path("/app/storage/db")
+    DB_DIR.mkdir(parents=True, exist_ok=True)
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+
+    class Config:
+        case_sensitive = True
+
+settings = Settings()

app/db/base.py

@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/migrations/env.py

@@ -0,0 +1,92 @@
+import asyncio
+from logging.config import fileConfig
+from pathlib import Path
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from sqlalchemy.ext.asyncio import AsyncEngine
+
+from alembic import context
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+from app.db.base import Base
+from app.models import Item  # Import all your models here
+target_metadata = Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+DB_DIR = Path("/app/storage/db")
+DB_DIR.mkdir(parents=True, exist_ok=True)
+config.set_main_option('sqlalchemy.url', f"sqlite+aiosqlite:///{DB_DIR}/db.sqlite")
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    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 do_run_migrations(connection):
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = AsyncEngine(
+        engine_from_config(
+            config.get_section(config.config_ini_section),
+            prefix="sqlalchemy.",
+            poolclass=pool.NullPool,
+            future=True,
+        )
+    )
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    asyncio.run(run_migrations_online())

app/db/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"}

app/db/migrations/versions/initial_migration.py

@@ -0,0 +1,40 @@
+"""Initial migration
+
+Revision ID: 8675309dee
+Revises: 
+Create Date: 2025-05-14
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '8675309dee'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('items',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(), nullable=True),
+        sa.Column('description', sa.String(), nullable=True),
+        sa.Column('is_active', sa.Boolean(), nullable=True),
+        sa.Column('created_at', sa.DateTime(), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), server_default=sa.text('(CURRENT_TIMESTAMP)'), nullable=True),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_items_id'), 'items', ['id'], unique=False)
+    op.create_index(op.f('ix_items_title'), 'items', ['title'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_items_title'), table_name='items')
+    op.drop_index(op.f('ix_items_id'), table_name='items')
+    op.drop_table('items')
+    # ### end Alembic commands ###

app/db/session.py

@@ -0,0 +1,32 @@
+from pathlib import Path
+from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
+from sqlalchemy.orm import sessionmaker
+from typing import Generator
+
+DB_DIR = Path("/app/storage/db")
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite+aiosqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_async_engine(
+    SQLALCHEMY_DATABASE_URL, 
+    connect_args={"check_same_thread": False},
+    echo=True
+)
+
+SessionLocal = sessionmaker(
+    autocommit=False, 
+    autoflush=False, 
+    bind=engine, 
+    class_=AsyncSession
+)
+
+async def get_db() -> Generator[AsyncSession, None, None]:
+    """
+    Dependency for getting async db session.
+    """
+    async with SessionLocal() as session:
+        try:
+            yield session
+        finally:
+            await session.close()

app/models/__init__.py

@@ -0,0 +1 @@
+from app.models.item import Item

app/models/item.py

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

app/schemas/__init__.py

@@ -0,0 +1 @@
+from app.schemas.item import ItemBase, ItemCreate, ItemUpdate, ItemResponse

app/schemas/item.py

@@ -0,0 +1,27 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+
+# Shared properties
+class ItemBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    is_active: Optional[bool] = True
+
+# Properties to receive on item creation
+class ItemCreate(ItemBase):
+    pass
+
+# Properties to receive on item update
+class ItemUpdate(ItemBase):
+    title: Optional[str] = None
+    is_active: Optional[bool] = None
+
+# Properties to return to client
+class ItemResponse(ItemBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+    
+    class Config:
+        from_attributes = True

main.py

@@ -0,0 +1,28 @@
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.v1 import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url=f"{settings.API_V1_STR}/openapi.json",
+    docs_url="/docs",
+    redoc_url="/redoc",
+)
+
+# Set all CORS enabled origins
+if settings.BACKEND_CORS_ORIGINS:
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=[str(origin) for origin in settings.BACKEND_CORS_ORIGINS],
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+
+app.include_router(api_router, prefix=settings.API_V1_STR)
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

requirements.txt

@@ -0,0 +1,8 @@
+fastapi>=0.103.1
+uvicorn>=0.23.2
+sqlalchemy>=2.0.21
+alembic>=1.12.0
+pydantic>=2.4.2
+pydantic-settings>=2.0.3
+aiosqlite>=0.19.0
+ruff>=0.0.290