Update app.py

app.py

@@ -1,5 +1,4 @@
 import gradio as gr
-import os
 from langchain_community.document_loaders import PyPDFLoader
 from langchain_community.vectorstores import FAISS
 from langchain.text_splitter import RecursiveCharacterTextSplitter
@@ -14,23 +13,10 @@ import warnings
 warnings.warn = warn
 warnings.filterwarnings('ignore')
 
-from dotenv import load_dotenv
-load_dotenv()
-
-from langchain.prompts import PromptTemplate
-from langchain_huggingface import (
-    HuggingFaceEmbeddings,
-    HuggingFaceEndpoint,
-)
-from langchain.schema.runnable import RunnablePassthrough
-from langchain.schema.output_parser import StrOutputParser
-
-# --- 1) CONFIG / SAFETY ---
-
-if not os.getenv("HUGGINGFACEHUB_API_TOKEN"):
-    print("HUGGINGFACEHUB_API_TOKEN not found. Add it to your Space secrets.")
-    raise SystemExit(1)
-
+# Set your Hugging Face API token here.
+# For deployment on Hugging Face, you can set this as an environment variable.
+import os
+os.environ["HUGGINGFACEHUB_API_TOKEN"] = "hf_YOUR_HUGGINGFACE_TOKEN"
 
 ## LLM - Using an open-source model from Hugging Face
 def get_llm():
@@ -41,6 +27,9 @@ def get_llm():
     repo_id = "mistralai/Mixtral-8x7B-Instruct-v0.1"
     llm = HuggingFaceHub(
         repo_id=repo_id,
+        # The 'task' parameter is required to specify the model's function.
+        # This fixes the 'Value error, Got invalid task None' error.
+        task="text-generation",
         model_kwargs={"temperature": 0.1, "max_length": 512}
     )
     return llm