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

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()),