Add FastAPI backend with agent system

backend/app/services/auth_service.py

@@ -0,0 +1,29 @@
+from datetime import datetime, timedelta
+from passlib.context import CryptContext
+from jose import jwt, JWTError
+from app.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: timedelta | None = None) -> str:
+    to_encode = data.copy()
+    expire = datetime.utcnow() + (expires_delta or timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES))
+    to_encode.update({"exp": expire})
+    return jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)
+
+
+def decode_token(token: str) -> dict | None:
+    try:
+        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
+        return payload
+    except JWTError:
+        return None