[JUNE 25] Permanent failover to Flash model for OAuth users after persistent 429 errors (#1376)

Co-authored-by: Scott Densmore <[email protected]>

3 files changed, 42 insertions, 3 deletions

diff --git a/packages/cli/src/ui/App.test.tsx b/packages/cli/src/ui/App.test.tsx
index 1271c86a..75de2cf2 100644
--- a/packages/cli/src/ui/App.test.tsx
+++ b/packages/cli/src/ui/App.test.tsx
@@ -125,6 +125,7 @@ vi.mock('@gemini-cli/core', async (importOriginal) => {
         getGeminiClient: vi.fn(() => ({})),
         getCheckpointingEnabled: vi.fn(() => opts.checkpointing ?? true),
         getAllGeminiMdFilenames: vi.fn(() => ['GEMINI.md']),
+        setFlashFallbackHandler: vi.fn(),
       };
     });
   return {
diff --git a/packages/cli/src/ui/App.tsx b/packages/cli/src/ui/App.tsx
index c25d74e2..7824f0f7 100644
--- a/packages/cli/src/ui/App.tsx
+++ b/packages/cli/src/ui/App.tsx
@@ -115,6 +115,7 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
   const [editorError, setEditorError] = useState<string | null>(null);
   const [footerHeight, setFooterHeight] = useState<number>(0);
   const [corgiMode, setCorgiMode] = useState(false);
+  const [currentModel, setCurrentModel] = useState(config.getModel());
   const [shellModeActive, setShellModeActive] = useState(false);
   const [showErrorDetails, setShowErrorDetails] = useState<boolean>(false);
   const [showToolDescriptions, setShowToolDescriptions] =
@@ -214,6 +215,42 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     }
   }, [config, addItem]);
 
+  // Watch for model changes (e.g., from Flash fallback)
+  useEffect(() => {
+    const checkModelChange = () => {
+      const configModel = config.getModel();
+      if (configModel !== currentModel) {
+        setCurrentModel(configModel);
+      }
+    };
+
+    // Check immediately and then periodically
+    checkModelChange();
+    const interval = setInterval(checkModelChange, 1000); // Check every second
+
+    return () => clearInterval(interval);
+  }, [config, currentModel]);
+
+  // Set up Flash fallback handler
+  useEffect(() => {
+    const flashFallbackHandler = async (
+      currentModel: string,
+      fallbackModel: string,
+    ): Promise<boolean> => {
+      // Add message to UI history
+      addItem(
+        {
+          type: MessageType.INFO,
+          text: `⚡ Rate limiting detected. Automatically switching from ${currentModel} to ${fallbackModel} for faster responses for the remainder of this session.`,
+        },
+        Date.now(),
+      );
+      return true; // Always accept the fallback
+    };
+
+    config.setFlashFallbackHandler(flashFallbackHandler);
+  }, [config, addItem]);
+
   const {
     handleSlashCommand,
     slashCommands,
@@ -787,7 +824,7 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
             </Box>
           )}
           <Footer
-            model={config.getModel()}
+            model={currentModel}
             targetDir={config.getTargetDir()}
             debugMode={config.getDebugMode()}
             branchName={branchName}
diff --git a/packages/cli/src/ui/hooks/slashCommandProcessor.ts b/packages/cli/src/ui/hooks/slashCommandProcessor.ts
index b9d3c0da..f76580b7 100644
--- a/packages/cli/src/ui/hooks/slashCommandProcessor.ts
+++ b/packages/cli/src/ui/hooks/slashCommandProcessor.ts
@@ -171,7 +171,7 @@ export const useSlashCommandProcessor = (
     [addMessage],
   );
 
-  const savedChatTags = async function () {
+  const savedChatTags = useCallback(async () => {
     const geminiDir = config?.getProjectTempDir();
     if (!geminiDir) {
       return [];
@@ -186,7 +186,7 @@ export const useSlashCommandProcessor = (
     } catch (_err) {
       return [];
     }
-  };
+  }, [config]);
 
   const slashCommands: SlashCommand[] = useMemo(() => {
     const commands: SlashCommand[] = [
@@ -992,6 +992,7 @@ Add any other context about the problem here.
     addMemoryAction,
     addMessage,
     toggleCorgiMode,
+    savedChatTags,
     config,
     showToolDescriptions,
     session,