Update app.py

app.py

@@ -455,8 +455,16 @@ async def get_session_status(session_id: str):
         if not session:
             raise HTTPException(status_code=404, detail="Session not found")
         
-        # Convert ObjectId to string for JSON serialization
+        # --- START FIX ---
+        # Convert all datetime objects to ISO 8601 strings
         session["_id"] = str(session["_id"])
+        if session.get("created_at"):
+            session["created_at"] = session["created_at"].isoformat()
+        if session.get("updated_at"):
+            session["updated_at"] = session["updated_at"].isoformat()
+        if session.get("processing_completed_at"):
+            session["processing_completed_at"] = session["processing_completed_at"].isoformat()
+        # --- END FIX ---
         
         # Add processing progress info
         if session["status"] == "completed":
@@ -517,7 +525,14 @@ async def get_processing_results(session_id: str):
         # Clean up ObjectIds
         for chunk in chunks_metadata:
             chunk["_id"] = str(chunk["_id"])
-        
+            
+        # --- START FIX ---
+        # Convert potential datetime object to an ISO 8601 string
+        processing_completed_at = session.get("processing_completed_at")
+        if processing_completed_at:
+            processing_completed_at = processing_completed_at.isoformat()
+        # --- END FIX ---
+            
         return JSONResponse(
             status_code=200,
             content={
@@ -530,7 +545,7 @@ async def get_processing_results(session_id: str):
                     "total_chunks": len(chunks_metadata),
                     "chunks": chunks_metadata[:10]  # Return first 10 chunks metadata
                 },
-                "processing_completed_at": session.get("processing_completed_at")
+                "processing_completed_at": processing_completed_at # Use the converted variable
             }
         )