diff --git a/packages/cli/src/gemini.test.tsx b/packages/cli/src/gemini.test.tsx
index 41f9978d7c1..2e55c9b25d1 100644
--- a/packages/cli/src/gemini.test.tsx
+++ b/packages/cli/src/gemini.test.tsx
@@ -238,18 +238,15 @@ vi.mock('./validateNonInterActiveAuth.js', () => ({
 }));
 
 describe('gemini.tsx main function', () => {
-  let originalEnvGeminiSandbox: string | undefined;
-  let originalEnvSandbox: string | undefined;
   let originalIsTTY: boolean | undefined;
   let initialUnhandledRejectionListeners: NodeJS.UnhandledRejectionListener[] =
     [];
 
   beforeEach(() => {
     // Store and clear sandbox-related env variables to ensure a consistent test environment
-    originalEnvGeminiSandbox = process.env['GEMINI_SANDBOX'];
-    originalEnvSandbox = process.env['SANDBOX'];
-    delete process.env['GEMINI_SANDBOX'];
-    delete process.env['SANDBOX'];
+    vi.stubEnv('GEMINI_SANDBOX', '');
+    vi.stubEnv('SANDBOX', '');
+    vi.stubEnv('SHPOOL_SESSION_NAME', '');
 
     initialUnhandledRejectionListeners =
       process.listeners('unhandledRejection');
@@ -260,18 +257,6 @@ describe('gemini.tsx main function', () => {
   });
 
   afterEach(() => {
-    // Restore original env variables
-    if (originalEnvGeminiSandbox !== undefined) {
-      process.env['GEMINI_SANDBOX'] = originalEnvGeminiSandbox;
-    } else {
-      delete process.env['GEMINI_SANDBOX'];
-    }
-    if (originalEnvSandbox !== undefined) {
-      process.env['SANDBOX'] = originalEnvSandbox;
-    } else {
-      delete process.env['SANDBOX'];
-    }
-
     const currentListeners = process.listeners('unhandledRejection');
     currentListeners.forEach((listener) => {
       if (!initialUnhandledRejectionListeners.includes(listener)) {
@@ -282,6 +267,7 @@ describe('gemini.tsx main function', () => {
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     (process.stdin as any).isTTY = originalIsTTY;
 
+    vi.unstubAllEnvs();
     vi.restoreAllMocks();
   });
 
@@ -1209,7 +1195,12 @@ describe('startInteractiveUI', () => {
     registerTelemetryConfig: vi.fn(),
   }));
 
+  beforeEach(() => {
+    vi.stubEnv('SHPOOL_SESSION_NAME', '');
+  });
+
   afterEach(() => {
+    vi.unstubAllEnvs();
     vi.restoreAllMocks();
   });
 
@@ -1308,7 +1299,7 @@ describe('startInteractiveUI', () => {
 
     // Verify all startup tasks were called
     expect(getVersion).toHaveBeenCalledTimes(1);
-    expect(registerCleanup).toHaveBeenCalledTimes(3);
+    expect(registerCleanup).toHaveBeenCalledTimes(4);
 
     // Verify cleanup handler is registered with unmount function
     const cleanupFn = vi.mocked(registerCleanup).mock.calls[0][0];
diff --git a/packages/cli/src/gemini.tsx b/packages/cli/src/gemini.tsx
index 68ce4c99b64..a18f3ace378 100644
--- a/packages/cli/src/gemini.tsx
+++ b/packages/cli/src/gemini.tsx
@@ -57,8 +57,8 @@ import {
   writeToStderr,
   disableMouseEvents,
   enableMouseEvents,
-  enterAlternateScreen,
   disableLineWrapping,
+  enableLineWrapping,
   shouldEnterAlternateScreen,
   startupProfiler,
   ExitCodes,
@@ -89,6 +89,7 @@ import { SessionStatsProvider } from './ui/contexts/SessionContext.js';
 import { VimModeProvider } from './ui/contexts/VimModeContext.js';
 import { KeypressProvider } from './ui/contexts/KeypressContext.js';
 import { useKittyKeyboardProtocol } from './ui/hooks/useKittyKeyboardProtocol.js';
+import { useTerminalSize } from './ui/hooks/useTerminalSize.js';
 import {
   relaunchAppInChildProcess,
   relaunchOnExitCode,
@@ -214,9 +215,13 @@ export async function startInteractiveUI(
 
   const { stdout: inkStdout, stderr: inkStderr } = createWorkingStdio();
 
+  const isShpool = !!process.env['SHPOOL_SESSION_NAME'];
+
   // Create wrapper component to use hooks inside render
   const AppWrapper = () => {
     useKittyKeyboardProtocol();
+    const { columns, rows } = useTerminalSize();
+
     return (
       <SettingsContext.Provider value={settings}>
         <KeypressProvider
@@ -234,6 +239,7 @@ export async function startInteractiveUI(
                 <SessionStatsProvider>
                   <VimModeProvider settings={settings}>
                     <AppContainer
+                      key={`${columns}-${rows}`}
                       config={config}
                       startupWarnings={startupWarnings}
                       version={version}
@@ -250,6 +256,17 @@ export async function startInteractiveUI(
     );
   };
 
+  if (isShpool) {
+    // Wait a moment for shpool to stabilize terminal size and state.
+    // shpool is a persistence tool that restores terminal state by replaying it.
+    // This delay gives shpool time to finish its restoration replay and send
+    // the actual terminal size (often via an immediate SIGWINCH) before we
+    // render the first TUI frame. Without this, the first frame may be
+    // garbled or rendered at an incorrect size, which disabling incremental
+    // rendering alone cannot fix for the initial frame.
+    await new Promise((resolve) => setTimeout(resolve, 100));
+  }
+
   const instance = render(
     process.env['DEBUG'] ? (
       <React.StrictMode>
@@ -273,10 +290,19 @@ export async function startInteractiveUI(
       patchConsole: false,
       alternateBuffer: useAlternateBuffer,
       incrementalRendering:
-        settings.merged.ui.incrementalRendering !== false && useAlternateBuffer,
+        settings.merged.ui.incrementalRendering !== false &&
+        useAlternateBuffer &&
+        !isShpool,
     },
   );
 
+  if (useAlternateBuffer) {
+    disableLineWrapping();
+    registerCleanup(() => {
+      enableLineWrapping();
+    });
+  }
+
   checkForUpdates(settings)
     .then((info) => {
       handleAutoUpdate(info, settings, config.getProjectRoot());
@@ -590,26 +616,13 @@ export async function main() {
       // input showing up in the output.
       process.stdin.setRawMode(true);
 
-      if (
-        shouldEnterAlternateScreen(
-          isAlternateBufferEnabled(settings),
-          config.getScreenReader(),
-        )
-      ) {
-        enterAlternateScreen();
-        disableLineWrapping();
-
-        // Ink will cleanup so there is no need for us to manually cleanup.
-      }
-
       // This cleanup isn't strictly needed but may help in certain situations.
-      const restoreRawMode = () => {
+      process.on('SIGTERM', () => {
         process.stdin.setRawMode(wasRaw);
-      };
-      process.off('SIGTERM', restoreRawMode);
-      process.on('SIGTERM', restoreRawMode);
-      process.off('SIGINT', restoreRawMode);
-      process.on('SIGINT', restoreRawMode);
+      });
+      process.on('SIGINT', () => {
+        process.stdin.setRawMode(wasRaw);
+      });
     }
 
     await setupTerminalAndTheme(config, settings);
diff --git a/packages/cli/src/ui/AppContainer.tsx b/packages/cli/src/ui/AppContainer.tsx
index 7d863a638fe..97e1cec2b7d 100644
--- a/packages/cli/src/ui/AppContainer.tsx
+++ b/packages/cli/src/ui/AppContainer.tsx
@@ -363,7 +363,9 @@ export const AppContainer = (props: AppContainerProps) => {
     (async () => {
       // Note: the program will not work if this fails so let errors be
       // handled by the global catch.
-      await config.initialize();
+      if (!config.isInitialized()) {
+        await config.initialize();
+      }
       setConfigInitialized(true);
       startupProfiler.flush(config);
 
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index 1570339010f..6d811799bc6 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -905,6 +905,10 @@ export class Config {
     );
   }
 
+  isInitialized(): boolean {
+    return this.initialized;
+  }
+
   /**
    * Must only be called once, throws if called again.
    */