"Fix DEV_MODE handling and RAGAgent initialization"

- Prioritize DEV_MODE explicitly during model selection
- Avoid ambiguous `model is None` checks
- Ensure model argument is always a valid identifier
- Clean up requirements.txt (remove duplicate entry, add newline at EOF)

This improves startup reliability and aligns with expected development
and production behavior.

Author: Naitik120gupta

app/ai.py

@@ -38,15 +38,14 @@ class RAGAgent:
 
     def __init__(self, model: Optional[str] = None, quantize: bool = True):
         # Determine which model to use based on DEV_MODE
-        if model is None:
-            if settings.DEV_MODE:
-                # Use a lightweight model that runs easily on CPUs/Low RAM
-                self.model_name = "google/flan-t5-small" 
-                print(f"🔧 DEV_MODE active: Switching to lightweight model: {self.model_name}")
-            else:
-                self.model_name = "google/gemma-3-27b-it"
-        else:
+        if settings.DEV_MODE:
+    # Use a lightweight model that runs easily on CPUs / low RAM
+            self.model_name = "google/flan-t5-small"
+            print(f"DEV_MODE active: Switching to lightweight model: {self.model_name}")
+        elif model is not None:
             self.model_name = model
+        else:
+            self.model_name = "google/gemma-3-27b-it"
 
         # Only quantize if it's NOT dev mode and CUDA is available
         self.use_quant = quantize and torch.cuda.is_available() and not settings.DEV_MODE

app/config.py

@@ -18,20 +18,21 @@ class Settings(BaseSettings):
     DOC_PATHS: List[str] = Field(default_factory=list)
     MAX_DAILY_REQUESTS: int = 100
 
+    # OAuth
     github_client_id: Optional[str] = None
     github_client_secret: Optional[str] = None
     google_client_id: Optional[str] = None
     google_client_secret: Optional[str] = None
     oauth_redirect_uri: Optional[str] = None
     session_secret_key: Optional[str] = None
-
-    port: int = 8000
+    
+    port: Optional[str] = None
+    
+    # application settings
     TEMPLATES_DIR: str = "templates"
+    
+    class Config:
+        env_file = ".env"
+        extra = "allow"  # this allows extra attribute if we have any
 
-    model_config = SettingsConfigDict(
-        env_file=".env",
-        env_file_encoding="utf-8",
-        extra="allow"
-    )
-
-settings = Settings()
+settings = Settings()

requirements.txt

@@ -18,4 +18,4 @@ itsdangerous
 httpx
 pydantic-settings
 sentence-transformers
-python-dotenv
+python-dotenv