Update app.py

app.py

@@ -26,52 +26,52 @@ with st.sidebar:
 
     # ---------- BEFORE VALIDATION ----------
     if not st.session_state.api_validated:
-        api_key_input = st.text_input(
-            "Enter Google API Key",
-            type="password",
-            key="api_key_input"
-        )
-
-        # Validate API Key immediately when button is clicked
-        if st.button("Validate API Key"):
-            if not api_key_input:
-                st.warning("Please enter an API key.")
-            else:
-                try:
-                    # Initialize client
-                    client = genai.Client(api_key=api_key_input)
+        with st.form("api_form", clear_on_submit=False):
+            api_key_input = st.text_input(
+                "Enter Google API Key",
+                type="password",
+                key="api_key_input"
+            )
+            submitted = st.form_submit_button("Validate API Key")
 
-                    # Attempt to list models (authentication test)
+            if submitted:
+                if not api_key_input:
+                    st.warning("Please enter an API key.")
+                else:
                     try:
-                        models = [
-                            m.name for m in client.models.list()
-                            if "gemini" in m.name.lower()
-                        ]
-                    except Exception:
-                        models = []
-
-                    # Persist validated state
-                    st.session_state.api_key = api_key_input
-                    st.session_state.client = client
-                    st.session_state.models = models or ["gemini-2.5-flash"]
-                    st.session_state.selected_model = st.session_state.models[0]
-                    st.session_state.api_validated = True
-
-                    st.success("✅ API key validated successfully")
-
-                except Exception as e:
-                    error_msg = str(e).lower()
-                    if "401" in error_msg or "403" in error_msg or "unauthorized" in error_msg:
-                        st.error("❌ Invalid API key")
-                    else:
-                        st.warning("⚠️ API key accepted, but model access may be restricted")
-                        st.caption(str(e))
+                        # Initialize client
+                        client = genai.Client(api_key=api_key_input)
+
+                        # Attempt to list models (authentication test)
+                        try:
+                            models = [
+                                m.name for m in client.models.list()
+                                if "gemini" in m.name.lower()
+                            ]
+                        except Exception:
+                            models = []
+
+                        # Persist validated state
+                        st.session_state.api_key = api_key_input
+                        st.session_state.client = client
+                        st.session_state.models = models or ["gemini-2.5-flash"]
+                        st.session_state.selected_model = st.session_state.models[0]
+                        st.session_state.api_validated = True
+
+                        st.success("✅ API key validated successfully")
+
+                    except Exception as e:
+                        error_msg = str(e).lower()
+                        if "401" in error_msg or "403" in error_msg or "unauthorized" in error_msg:
+                            st.error("❌ Invalid API key")
+                        else:
+                            st.warning("⚠️ API key accepted, but model access may be restricted")
+                            st.caption(str(e))
 
     # ---------- AFTER VALIDATION ----------
     else:
         st.success("🔒 API Key validated (hidden)")
 
-        # Model selector is now immediately visible
         st.selectbox(
             "Available Models",
             st.session_state.models,