app/database.py

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base
from app.config import settings

# pool_pre_ping prevents stale connection errors common with remote clouds like Supabase
# pool_size and max_overflow keep us safely within Supabase free-tier connection limits
engine = create_engine(
    settings.DATABASE_URL,
    pool_pre_ping=True,
    pool_size=5,
    max_overflow=10
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()