Update app.py

app.py

@@ -6,6 +6,21 @@ from langchain.llms import OpenAI, HuggingFaceHub
 from langchain.embeddings import OpenAIEmbeddings, HuggingFaceEmbeddings
 from langchain.document_loaders import PyPDFLoader
 import time
+from langchain_huggingface import HuggingFaceEndpoint
+
+
+# Fetch API token securely from environment variables
+HUGGINGFACE_API_KEY = os.getenv("HUGGINGFACEHUB_API_TOKEN")
+
+if HUGGINGFACE_API_KEY is None:
+    raise ValueError("Hugging Face API token is missing! Set it as a secret in Hugging Face Spaces.")
+
+# Load LLM securely
+llm = HuggingFaceEndpoint(
+    repo_id="google/flan-t5-large",
+    model_kwargs={"temperature": 0.5, "max_length": 512},
+    huggingfacehub_api_token=HUGGINGFACE_API_KEY  # ✅ Secure API key usage
+)
 
 # Define paths for cybersecurity training PDFs
 PDF_FILES = [