Feature: Allow users to enter their own Serper API key in UI

app.py

@@ -37,7 +37,7 @@ class DocumentChatbot:
     Main chatbot application class
     """
     
-    def __init__(self):
+    def __init__(self, serper_api_key: str = None):
         self.doc_processor = DocumentProcessor()
         self.vector_store = VectorStore()
         self.query_router = QueryRouter()
@@ -47,10 +47,16 @@ class DocumentChatbot:
         self.hf_client, self.model_loaded = get_hf_client()
         
         # Initialize web searcher if API key is available
+        self.init_web_search(serper_api_key)
+    
+    def init_web_search(self, api_key: str = None):
+        """Initialize or reinitialize web search with provided API key"""
         try:
-            self.web_searcher = WebSearcher()
+            self.web_searcher = WebSearcher(api_key=api_key)
+            return True
         except ValueError as e:
-            st.warning(f"Web search disabled: {str(e)}")
+            self.web_searcher = None
+            return False
         
         # Load existing index if available
         self.vector_store.load_index()
@@ -265,7 +271,9 @@ def main():
     
     # Initialize session state
     if 'chatbot' not in st.session_state:
-        st.session_state.chatbot = DocumentChatbot()
+        # Try to get API key from environment variable first
+        env_api_key = os.getenv("SERPER_API_KEY")
+        st.session_state.chatbot = DocumentChatbot(serper_api_key=env_api_key)
     
     if 'chat_history' not in st.session_state:
         st.session_state.chat_history = []
@@ -319,12 +327,48 @@ def main():
             st.warning("⚠️ AI model loading...")
             st.info("Models are being downloaded. This may take a few minutes on first run.")
         
-        st.subheader("Web Search")
-        if st.session_state.chatbot.web_searcher:
-            st.success("Web search enabled")
+        # Web Search Configuration
+        st.subheader("🌐 Web Search")
+        
+        # Check if web search is already enabled
+        web_search_enabled = st.session_state.chatbot.web_searcher is not None
+        
+        if web_search_enabled:
+            st.success("✅ Web search enabled")
+            if st.button("🔄 Change API Key"):
+                st.session_state.show_api_input = True
+                st.rerun()
         else:
-            st.error("Web search disabled")
-            st.info("Add SERPER_API_KEY to .env file to enable web search")
+            st.warning("⚠️ Web search disabled")
+            
+        # Show API key input field
+        if not web_search_enabled or st.session_state.get('show_api_input', False):
+            st.markdown("---")
+            st.markdown("**Enter your Serper API Key:**")
+            st.caption("Get a free API key at [serper.dev](https://serper.dev/) (2,500 searches/month free)")
+            
+            api_key = st.text_input(
+                "Serper API Key",
+                type="password",
+                placeholder="Enter your API key here",
+                help="Your API key is not stored and only used during this session",
+                key="serper_api_key_input"
+            )
+            
+            if api_key:
+                if st.button("Enable Web Search", type="primary"):
+                    success = st.session_state.chatbot.init_web_search(api_key)
+                    if success:
+                        st.success("✅ Web search enabled!")
+                        st.session_state.show_api_input = False
+                        st.rerun()
+                    else:
+                        st.error("❌ Invalid API key. Please check and try again.")
+            
+            if not api_key:
+                st.info("💡 Web search is optional. The chatbot works with documents only.")
+        
+        st.markdown("---")
     
     # Main chat interface
     st.header("Chat Interface")