Update app.py

app.py

@@ -1,4 +1,6 @@
+# app.py  –  Streamlit Summarizer (dotenv version)
 import os, re, validators, streamlit as st
+from dotenv import load_dotenv                                # ← NEW
 from youtube_transcript_api import YouTubeTranscriptApi, TranscriptsDisabled, VideoUnavailable
 from langchain.prompts import PromptTemplate
 from langchain.chains.summarize import load_summarize_chain
@@ -7,22 +9,19 @@ from langchain.schema import Document
 from langchain_community.document_loaders import UnstructuredURLLoader
 from langchain.document_loaders import PyPDFLoader
 
-# ─────────────────────────  STREAMLIT CONFIG  ──────────────────────────
+# ───────────────  load variables from .env  (runs before anything else)
+load_dotenv()                              # looks for .env in project root
+GROQ_KEY = os.getenv("GROQ_API_KEY")       # expect GROQ_API_KEY=xxx in .env
+
+# ──────────────────────────  STREAMLIT CONFIG  ────────────────────────
 st.set_page_config(page_title="LangChain Summarizer", page_icon="🦜")
 st.title("🦜 LangChain: Summarize YT / Webpage / PDF")
 
-# ────────────────────────────  API KEY INPUT  ──────────────────────────
-with st.sidebar:
-    st.header("API keys")
-    groq_api_key = st.text_input("Groq API Key", type="password")
-    if groq_api_key:
-        os.environ["GROQ_API_KEY"] = groq_api_key          # for libraries
-
-# ─────────────────────  PLACEHOLDERS / FILE & URL INPUT  ───────────────
+# ─────────────────────  PLACEHOLDERS / FILE & URL INPUT  ──────────────
 generic_url   = st.text_input("Paste a YouTube / web URL here:")
 uploaded_file = st.file_uploader("…or upload a PDF", type=["pdf"])
 
-# ──────────────────────────  UTILITY FUNCTIONS  ────────────────────────
+# ──────────────────────────  UTILITY FUNCTIONS  ───────────────────────
 def get_video_id(url: str) -> str | None:
     m = re.search(r"(?:v=|\/)([0-9A-Za-z_-]{11})", url)
     return m.group(1) if m else None
@@ -35,9 +34,14 @@ SUMMARY_PROMPT = PromptTemplate(
 def build_llm() -> ChatGroq:
     """Instantiate ChatGroq once and cache it in session_state."""
     if "llm" not in st.session_state:
+        if not GROQ_KEY:
+            raise RuntimeError(
+                "❌ Groq API key not found. "
+                "Add GROQ_API_KEY to a `.env` file or the environment."
+            )
         st.session_state.llm = ChatGroq(
             model="llama3-70b-8192",
-            groq_api_key=os.environ["GROQ_API_KEY"],
+            groq_api_key=GROQ_KEY,
         )
     return st.session_state.llm
 
@@ -46,10 +50,10 @@ def summarize(docs):
     chain = load_summarize_chain(llm, chain_type="stuff", prompt=SUMMARY_PROMPT)
     return chain({"input_documents": docs})["output_text"]
 
-# ─────────────────────────────  MAIN ACTION  ───────────────────────────
+# ─────────────────────────────  MAIN ACTION  ──────────────────────────
 if st.button("Summarize"):
-    if not groq_api_key:
-        st.error("Please enter your Groq API key in the sidebar.")
+    if not GROQ_KEY:
+        st.error("Groq key missing. Set **GROQ_API_KEY** in your `.env`.")
     elif not generic_url and not uploaded_file:
         st.error("Provide a URL or upload a PDF, then press Summarize.")
     else: