Add NO_BROWSER environment variable to trigger offline oauth flow (#3713)

packages/cli/src/config/config.ts

@@ -317,6 +317,7 @@ export async function loadCliConfig(
       name: e.config.name,
       version: e.config.version,
     })),
+    noBrowser: !!process.env.NO_BROWSER,
   });
 }
 

packages/cli/src/gemini.tsx

@@ -35,6 +35,7 @@ import {
   sessionId,
   logUserPrompt,
   AuthType,
+  getOauthClient,
 } from '@google/gemini-cli-core';
 import { validateAuthMethod } from './config/auth.js';
 import { setMaxSizedBoxDebugging } from './ui/components/shared/MaxSizedBox.js';
@@ -165,6 +166,15 @@ export async function main() {
       }
     }
   }
+
+  if (
+    settings.merged.selectedAuthType === AuthType.LOGIN_WITH_GOOGLE &&
+    config.getNoBrowser()
+  ) {
+    // Do oauth before app renders to make copying the link possible.
+    await getOauthClient(settings.merged.selectedAuthType, config);
+  }
+
   let input = config.getQuestion();
   const startupWarnings = [
     ...(await getStartupWarnings()),

packages/cli/src/ui/App.tsx

@@ -728,13 +728,29 @@ const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
               />
             </Box>
           ) : isAuthenticating ? (
-            <AuthInProgress
-              onTimeout={() => {
-                setAuthError('Authentication timed out. Please try again.');
-                cancelAuthentication();
-                openAuthDialog();
-              }}
-            />
+            <>
+              <AuthInProgress
+                onTimeout={() => {
+                  setAuthError('Authentication timed out. Please try again.');
+                  cancelAuthentication();
+                  openAuthDialog();
+                }}
+              />
+              {showErrorDetails && (
+                <OverflowProvider>
+                  <Box flexDirection="column">
+                    <DetailedMessagesDisplay
+                      messages={filteredConsoleMessages}
+                      maxHeight={
+                        constrainHeight ? debugConsoleMaxHeight : undefined
+                      }
+                      width={inputWidth}
+                    />
+                    <ShowMoreLines constrainHeight={constrainHeight} />
+                  </Box>
+                </OverflowProvider>
+              )}
+            </>
           ) : isAuthDialogOpen ? (
             <Box flexDirection="column">
               <AuthDialog