fix(core): improve headless mode detection for flags and query args (#18855)

packages/cli/src/config/config.ts

@@ -445,7 +445,11 @@ export async function loadCliConfig(
     process.env['VITEST'] === 'true'
       ? false
       : (settings.security?.folderTrust?.enabled ?? false);
-  const trustedFolder = isWorkspaceTrusted(settings, cwd)?.isTrusted ?? false;
+  const trustedFolder =
+    isWorkspaceTrusted(settings, cwd, undefined, {
+      prompt: argv.prompt,
+      query: argv.query,
+    })?.isTrusted ?? false;
 
   // Set the context filename in the server's memoryTool module BEFORE loading memory
   // TODO(b/343434939): This is a bit of a hack. The contextFileName should ideally be passed
@@ -602,8 +606,7 @@ export async function loadCliConfig(
   const interactive =
     !!argv.promptInteractive ||
     !!argv.experimentalAcp ||
-    (!isHeadlessMode({ prompt: argv.prompt }) &&
-      !argv.query &&
+    (!isHeadlessMode({ prompt: argv.prompt, query: argv.query }) &&
       !argv.isCommand);
 
   const allowedTools = argv.allowedTools || settings.tools?.allowed || [];

packages/cli/src/config/trustedFolders.test.ts

@@ -449,6 +449,14 @@ describe('Trusted Folders', () => {
         false,
       );
     });
+
+    it('should return true for isPathTrusted when isHeadlessMode is true', async () => {
+      const geminiCore = await import('@google/gemini-cli-core');
+      vi.spyOn(geminiCore, 'isHeadlessMode').mockReturnValue(true);
+
+      const folders = loadTrustedFolders();
+      expect(folders.isPathTrusted('/any-untrusted-path')).toBe(true);
+    });
   });
 
   describe('Trusted Folders Caching', () => {

packages/cli/src/config/trustedFolders.ts

@@ -17,6 +17,7 @@ import {
   homedir,
   isHeadlessMode,
   coreEvents,
+  type HeadlessModeOptions,
 } from '@google/gemini-cli-core';
 import type { Settings } from './settings.js';
 import stripJsonComments from 'strip-json-comments';
@@ -128,7 +129,11 @@ export class LoadedTrustedFolders {
   isPathTrusted(
     location: string,
     config?: Record<string, TrustLevel>,
+    headlessOptions?: HeadlessModeOptions,
   ): boolean | undefined {
+    if (isHeadlessMode(headlessOptions)) {
+      return true;
+    }
     const configToUse = config ?? this.user.config;
 
     // Resolve location to its realpath for canonical comparison
@@ -333,6 +338,7 @@ export function isFolderTrustEnabled(settings: Settings): boolean {
 function getWorkspaceTrustFromLocalConfig(
   workspaceDir: string,
   trustConfig?: Record<string, TrustLevel>,
+  headlessOptions?: HeadlessModeOptions,
 ): TrustResult {
   const folders = loadTrustedFolders();
   const configToUse = trustConfig ?? folders.user.config;
@@ -346,7 +352,11 @@ function getWorkspaceTrustFromLocalConfig(
     );
   }
 
-  const isTrusted = folders.isPathTrusted(workspaceDir, configToUse);
+  const isTrusted = folders.isPathTrusted(
+    workspaceDir,
+    configToUse,
+    headlessOptions,
+  );
   return {
     isTrusted,
     source: isTrusted !== undefined ? 'file' : undefined,
@@ -357,8 +367,9 @@ export function isWorkspaceTrusted(
   settings: Settings,
   workspaceDir: string = process.cwd(),
   trustConfig?: Record<string, TrustLevel>,
+  headlessOptions?: HeadlessModeOptions,
 ): TrustResult {
-  if (isHeadlessMode()) {
+  if (isHeadlessMode(headlessOptions)) {
     return { isTrusted: true, source: undefined };
   }
 
@@ -372,5 +383,9 @@ export function isWorkspaceTrusted(
   }
 
   // Fall back to the local user configuration
-  return getWorkspaceTrustFromLocalConfig(workspaceDir, trustConfig);
+  return getWorkspaceTrustFromLocalConfig(
+    workspaceDir,
+    trustConfig,
+    headlessOptions,
+  );
 }

packages/core/src/utils/headless.test.ts

@@ -99,16 +99,50 @@ describe('isHeadlessMode', () => {
     expect(isHeadlessMode({ prompt: true })).toBe(true);
   });
 
-  it('should return false if query is provided but it is still a TTY', () => {
-    // Note: per current logic, query alone doesn't force headless if TTY
-    // This matches the existing behavior in packages/cli/src/config/config.ts
-    expect(isHeadlessMode({ query: 'test query' })).toBe(false);
+  it('should return true if query is provided', () => {
+    expect(isHeadlessMode({ query: 'test query' })).toBe(true);
+  });
+
+  it('should return true if -p or --prompt is in process.argv as a fallback', () => {
+    const originalArgv = process.argv;
+    process.argv = ['node', 'index.js', '-p', 'hello'];
+    try {
+      expect(isHeadlessMode()).toBe(true);
+    } finally {
+      process.argv = originalArgv;
+    }
+
+    process.argv = ['node', 'index.js', '--prompt', 'hello'];
+    try {
+      expect(isHeadlessMode()).toBe(true);
+    } finally {
+      process.argv = originalArgv;
+    }
+  });
+
+  it('should return true if -y or --yolo is in process.argv as a fallback', () => {
+    const originalArgv = process.argv;
+    process.argv = ['node', 'index.js', '-y'];
+    try {
+      expect(isHeadlessMode()).toBe(true);
+    } finally {
+      process.argv = originalArgv;
+    }
+
+    process.argv = ['node', 'index.js', '--yolo'];
+    try {
+      expect(isHeadlessMode()).toBe(true);
+    } finally {
+      process.argv = originalArgv;
+    }
   });
 
   it('should handle undefined process.stdout gracefully', () => {
     const originalStdout = process.stdout;
-    // @ts-expect-error - testing edge case
-    delete process.stdout;
+    Object.defineProperty(process, 'stdout', {
+      value: undefined,
+      configurable: true,
+    });
 
     try {
       expect(isHeadlessMode()).toBe(false);
@@ -122,8 +156,10 @@ describe('isHeadlessMode', () => {
 
   it('should handle undefined process.stdin gracefully', () => {
     const originalStdin = process.stdin;
-    // @ts-expect-error - testing edge case
-    delete process.stdin;
+    Object.defineProperty(process, 'stdin', {
+      value: undefined,
+      configurable: true,
+    });
 
     try {
       expect(isHeadlessMode()).toBe(false);

packages/core/src/utils/headless.ts

@@ -28,18 +28,25 @@ export interface HeadlessModeOptions {
  * @returns true if the environment is considered headless.
  */
 export function isHeadlessMode(options?: HeadlessModeOptions): boolean {
-  if (process.env['GEMINI_CLI_INTEGRATION_TEST'] === 'true') {
-    return (
-      !!options?.prompt ||
-      (!!process.stdin && !process.stdin.isTTY) ||
-      (!!process.stdout && !process.stdout.isTTY)
-    );
+  if (process.env['GEMINI_CLI_INTEGRATION_TEST'] !== 'true') {
+    const isCI =
+      process.env['CI'] === 'true' || process.env['GITHUB_ACTIONS'] === 'true';
+    if (isCI) {
+      return true;
+    }
   }
-  return (
-    process.env['CI'] === 'true' ||
-    process.env['GITHUB_ACTIONS'] === 'true' ||
-    !!options?.prompt ||
+
+  const isNotTTY =
     (!!process.stdin && !process.stdin.isTTY) ||
-    (!!process.stdout && !process.stdout.isTTY)
+    (!!process.stdout && !process.stdout.isTTY);
+
+  if (isNotTTY || !!options?.prompt || !!options?.query) {
+    return true;
+  }
+
+  // Fallback: check process.argv for flags that imply headless or auto-approve mode.
+  return process.argv.some(
+    (arg) =>
+      arg === '-p' || arg === '--prompt' || arg === '-y' || arg === '--yolo',
   );
 }