feat: Initialize FastAPI AI Gateway project structure with authentication, module management, and LLM API routing.

app/core/config.py

@@ -0,0 +1,18 @@
+import os
+from dotenv import load_dotenv
+
+load_dotenv()
+
+class Settings:
+    PROJECT_NAME: str = "Storyline AI Gateway"
+    API_KEY: str = os.getenv("API_KEY", "storyline-secret-key-123")
+    RATE_LIMIT: str = "20/minute"
+    GOOGLE_API_KEY: str = os.getenv("GOOGLE_API_KEY")
+    OPENAI_API_KEY: str = os.getenv("OPENAI_API_KEY")
+    DATABASE_URL: str = os.getenv("DATABASE_URL")
+    SECRET_KEY: str = os.getenv("SECRET_KEY", "your-super-secret-key-change-me")
+    ALGORITHM: str = "HS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60
+    ADMIN_PASSWORD: str = os.getenv("ADMIN_PASSWORD", "admin123")
+
+settings = Settings()

app/core/database.py

@@ -0,0 +1,24 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+from app.core.config import settings
+
+# For development, we can use SQLite if DATABASE_URL is not set or for simplicity
+# But we'll follow the user's request for PostgreSQL
+SQLALCHEMY_DATABASE_URL = settings.DATABASE_URL or "sqlite:///./sql_app.db"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, 
+    # check_same_thread is only needed for SQLite
+    **({"connect_args": {"check_same_thread": False}} if "sqlite" in SQLALCHEMY_DATABASE_URL else {})
+)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/core/limiter.py

@@ -0,0 +1,4 @@
+from slowapi import Limiter
+from slowapi.util import get_remote_address
+
+limiter = Limiter(key_func=get_remote_address)

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 fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from app.core.config import settings
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/auth/login")
+
+def verify_password(plain_password, hashed_password):
+    return pwd_context.verify(plain_password, hashed_password)
+
+def get_password_hash(password):
+    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
+
+async def get_current_user(token: str = Depends(oauth2_scheme)):
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Could not validate credentials",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+    try:
+        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
+        username: str = payload.get("sub")
+        if username is None:
+            raise credentials_exception
+    except JWTError:
+        raise credentials_exception
+    return username