feat: add --approval-mode parameter (#6024)

Co-authored-by: Jacob Richman <[email protected]>

4 files changed, 581 insertions, 9 deletions

diff --git a/docs/cli/configuration.md b/docs/cli/configuration.md
index 6ebcd630..d95793f1 100644
--- a/docs/cli/configuration.md
+++ b/docs/cli/configuration.md
@@ -422,6 +422,13 @@ Arguments passed directly when running the CLI can override other configurations
   - Displays the current memory usage.
 - **`--yolo`**:
   - Enables YOLO mode, which automatically approves all tool calls.
+- **`--approval-mode <mode>`**:
+  - Sets the approval mode for tool calls. Available modes:
+    - `default`: Prompt for approval on each tool call (default behavior)
+    - `auto_edit`: Automatically approve edit tools (replace, write_file) while prompting for others
+    - `yolo`: Automatically approve all tool calls (equivalent to `--yolo`)
+  - Cannot be used together with `--yolo`. Use `--approval-mode=yolo` instead of `--yolo` for the new unified approach.
+  - Example: `gemini --approval-mode auto_edit`
 - **`--telemetry`**:
   - Enables [telemetry](../telemetry.md).
 - **`--telemetry-target`**:
@@ -517,7 +524,7 @@ Sandboxing is disabled by default, but you can enable it in a few ways:
 
 - Using `--sandbox` or `-s` flag.
 - Setting `GEMINI_SANDBOX` environment variable.
-- Sandbox is enabled in `--yolo` mode by default.
+- Sandbox is enabled when using `--yolo` or `--approval-mode=yolo` by default.
 
 By default, it uses a pre-built `gemini-cli-sandbox` Docker image.
 
diff --git a/packages/cli/src/config/config.integration.test.ts b/packages/cli/src/config/config.integration.test.ts
index 87a74578..45ed6d82 100644
--- a/packages/cli/src/config/config.integration.test.ts
+++ b/packages/cli/src/config/config.integration.test.ts
@@ -261,4 +261,149 @@ describe('Configuration Integration Tests', () => {
       expect(config.getExtensionContextFilePaths()).toEqual(contextFiles);
     });
   });
+
+  describe('Approval Mode Integration Tests', () => {
+    let parseArguments: typeof import('./config').parseArguments;
+
+    beforeEach(async () => {
+      // Import the argument parsing function for integration testing
+      const { parseArguments: parseArgs } = await import('./config');
+      parseArguments = parseArgs;
+    });
+
+    it('should parse --approval-mode=auto_edit correctly through the full argument parsing flow', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        process.argv = [
+          'node',
+          'script.js',
+          '--approval-mode',
+          'auto_edit',
+          '-p',
+          'test',
+        ];
+
+        const argv = await parseArguments();
+
+        // Verify that the argument was parsed correctly
+        expect(argv.approvalMode).toBe('auto_edit');
+        expect(argv.prompt).toBe('test');
+        expect(argv.yolo).toBe(false);
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+
+    it('should parse --approval-mode=yolo correctly through the full argument parsing flow', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        process.argv = [
+          'node',
+          'script.js',
+          '--approval-mode',
+          'yolo',
+          '-p',
+          'test',
+        ];
+
+        const argv = await parseArguments();
+
+        expect(argv.approvalMode).toBe('yolo');
+        expect(argv.prompt).toBe('test');
+        expect(argv.yolo).toBe(false); // Should NOT be set when using --approval-mode
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+
+    it('should parse --approval-mode=default correctly through the full argument parsing flow', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        process.argv = [
+          'node',
+          'script.js',
+          '--approval-mode',
+          'default',
+          '-p',
+          'test',
+        ];
+
+        const argv = await parseArguments();
+
+        expect(argv.approvalMode).toBe('default');
+        expect(argv.prompt).toBe('test');
+        expect(argv.yolo).toBe(false);
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+
+    it('should parse legacy --yolo flag correctly', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        process.argv = ['node', 'script.js', '--yolo', '-p', 'test'];
+
+        const argv = await parseArguments();
+
+        expect(argv.yolo).toBe(true);
+        expect(argv.approvalMode).toBeUndefined(); // Should NOT be set when using --yolo
+        expect(argv.prompt).toBe('test');
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+
+    it('should reject invalid approval mode values during argument parsing', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        process.argv = ['node', 'script.js', '--approval-mode', 'invalid_mode'];
+
+        // Should throw during argument parsing due to yargs validation
+        await expect(parseArguments()).rejects.toThrow();
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+
+    it('should reject conflicting --yolo and --approval-mode flags', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        process.argv = [
+          'node',
+          'script.js',
+          '--yolo',
+          '--approval-mode',
+          'default',
+        ];
+
+        // Should throw during argument parsing due to conflict validation
+        await expect(parseArguments()).rejects.toThrow();
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+
+    it('should handle backward compatibility with mixed scenarios', async () => {
+      const originalArgv = process.argv;
+
+      try {
+        // Test that no approval mode arguments defaults to no flags set
+        process.argv = ['node', 'script.js', '-p', 'test'];
+
+        const argv = await parseArguments();
+
+        expect(argv.approvalMode).toBeUndefined();
+        expect(argv.yolo).toBe(false);
+        expect(argv.prompt).toBe('test');
+      } finally {
+        process.argv = originalArgv;
+      }
+    });
+  });
 });
diff --git a/packages/cli/src/config/config.test.ts b/packages/cli/src/config/config.test.ts
index 178980eb..fc4d24bd 100644
--- a/packages/cli/src/config/config.test.ts
+++ b/packages/cli/src/config/config.test.ts
@@ -156,6 +156,93 @@ describe('parseArguments', () => {
     expect(argv.promptInteractive).toBe('interactive prompt');
     expect(argv.prompt).toBeUndefined();
   });
+
+  it('should throw an error when both --yolo and --approval-mode are used together', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--yolo',
+      '--approval-mode',
+      'default',
+    ];
+
+    const mockExit = vi.spyOn(process, 'exit').mockImplementation(() => {
+      throw new Error('process.exit called');
+    });
+
+    const mockConsoleError = vi
+      .spyOn(console, 'error')
+      .mockImplementation(() => {});
+
+    await expect(parseArguments()).rejects.toThrow('process.exit called');
+
+    expect(mockConsoleError).toHaveBeenCalledWith(
+      expect.stringContaining(
+        'Cannot use both --yolo (-y) and --approval-mode together. Use --approval-mode=yolo instead.',
+      ),
+    );
+
+    mockExit.mockRestore();
+    mockConsoleError.mockRestore();
+  });
+
+  it('should throw an error when using short flags -y and --approval-mode together', async () => {
+    process.argv = ['node', 'script.js', '-y', '--approval-mode', 'yolo'];
+
+    const mockExit = vi.spyOn(process, 'exit').mockImplementation(() => {
+      throw new Error('process.exit called');
+    });
+
+    const mockConsoleError = vi
+      .spyOn(console, 'error')
+      .mockImplementation(() => {});
+
+    await expect(parseArguments()).rejects.toThrow('process.exit called');
+
+    expect(mockConsoleError).toHaveBeenCalledWith(
+      expect.stringContaining(
+        'Cannot use both --yolo (-y) and --approval-mode together. Use --approval-mode=yolo instead.',
+      ),
+    );
+
+    mockExit.mockRestore();
+    mockConsoleError.mockRestore();
+  });
+
+  it('should allow --approval-mode without --yolo', async () => {
+    process.argv = ['node', 'script.js', '--approval-mode', 'auto_edit'];
+    const argv = await parseArguments();
+    expect(argv.approvalMode).toBe('auto_edit');
+    expect(argv.yolo).toBe(false);
+  });
+
+  it('should allow --yolo without --approval-mode', async () => {
+    process.argv = ['node', 'script.js', '--yolo'];
+    const argv = await parseArguments();
+    expect(argv.yolo).toBe(true);
+    expect(argv.approvalMode).toBeUndefined();
+  });
+
+  it('should reject invalid --approval-mode values', async () => {
+    process.argv = ['node', 'script.js', '--approval-mode', 'invalid'];
+
+    const mockExit = vi.spyOn(process, 'exit').mockImplementation(() => {
+      throw new Error('process.exit called');
+    });
+
+    const mockConsoleError = vi
+      .spyOn(console, 'error')
+      .mockImplementation(() => {});
+
+    await expect(parseArguments()).rejects.toThrow('process.exit called');
+
+    expect(mockConsoleError).toHaveBeenCalledWith(
+      expect.stringContaining('Invalid values:'),
+    );
+
+    mockExit.mockRestore();
+    mockConsoleError.mockRestore();
+  });
 });
 
 describe('loadCliConfig', () => {
@@ -760,6 +847,211 @@ describe('mergeExcludeTools', () => {
   });
 });
 
+describe('Approval mode tool exclusion logic', () => {
+  const originalIsTTY = process.stdin.isTTY;
+
+  beforeEach(() => {
+    process.stdin.isTTY = false; // Ensure non-interactive mode
+  });
+
+  afterEach(() => {
+    process.stdin.isTTY = originalIsTTY;
+  });
+
+  it('should exclude all interactive tools in non-interactive mode with default approval mode', async () => {
+    process.argv = ['node', 'script.js', '-p', 'test'];
+    const argv = await parseArguments();
+    const settings: Settings = {};
+    const extensions: Extension[] = [];
+
+    const config = await loadCliConfig(
+      settings,
+      extensions,
+      'test-session',
+      argv,
+    );
+
+    const excludedTools = config.getExcludeTools();
+    expect(excludedTools).toContain(ShellTool.Name);
+    expect(excludedTools).toContain(EditTool.Name);
+    expect(excludedTools).toContain(WriteFileTool.Name);
+  });
+
+  it('should exclude all interactive tools in non-interactive mode with explicit default approval mode', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--approval-mode',
+      'default',
+      '-p',
+      'test',
+    ];
+    const argv = await parseArguments();
+    const settings: Settings = {};
+    const extensions: Extension[] = [];
+
+    const config = await loadCliConfig(
+      settings,
+      extensions,
+      'test-session',
+      argv,
+    );
+
+    const excludedTools = config.getExcludeTools();
+    expect(excludedTools).toContain(ShellTool.Name);
+    expect(excludedTools).toContain(EditTool.Name);
+    expect(excludedTools).toContain(WriteFileTool.Name);
+  });
+
+  it('should exclude only shell tools in non-interactive mode with auto_edit approval mode', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--approval-mode',
+      'auto_edit',
+      '-p',
+      'test',
+    ];
+    const argv = await parseArguments();
+    const settings: Settings = {};
+    const extensions: Extension[] = [];
+
+    const config = await loadCliConfig(
+      settings,
+      extensions,
+      'test-session',
+      argv,
+    );
+
+    const excludedTools = config.getExcludeTools();
+    expect(excludedTools).toContain(ShellTool.Name);
+    expect(excludedTools).not.toContain(EditTool.Name);
+    expect(excludedTools).not.toContain(WriteFileTool.Name);
+  });
+
+  it('should exclude no interactive tools in non-interactive mode with yolo approval mode', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--approval-mode',
+      'yolo',
+      '-p',
+      'test',
+    ];
+    const argv = await parseArguments();
+    const settings: Settings = {};
+    const extensions: Extension[] = [];
+
+    const config = await loadCliConfig(
+      settings,
+      extensions,
+      'test-session',
+      argv,
+    );
+
+    const excludedTools = config.getExcludeTools();
+    expect(excludedTools).not.toContain(ShellTool.Name);
+    expect(excludedTools).not.toContain(EditTool.Name);
+    expect(excludedTools).not.toContain(WriteFileTool.Name);
+  });
+
+  it('should exclude no interactive tools in non-interactive mode with legacy yolo flag', async () => {
+    process.argv = ['node', 'script.js', '--yolo', '-p', 'test'];
+    const argv = await parseArguments();
+    const settings: Settings = {};
+    const extensions: Extension[] = [];
+
+    const config = await loadCliConfig(
+      settings,
+      extensions,
+      'test-session',
+      argv,
+    );
+
+    const excludedTools = config.getExcludeTools();
+    expect(excludedTools).not.toContain(ShellTool.Name);
+    expect(excludedTools).not.toContain(EditTool.Name);
+    expect(excludedTools).not.toContain(WriteFileTool.Name);
+  });
+
+  it('should not exclude interactive tools in interactive mode regardless of approval mode', async () => {
+    process.stdin.isTTY = true; // Interactive mode
+
+    const testCases = [
+      { args: ['node', 'script.js'] }, // default
+      { args: ['node', 'script.js', '--approval-mode', 'default'] },
+      { args: ['node', 'script.js', '--approval-mode', 'auto_edit'] },
+      { args: ['node', 'script.js', '--approval-mode', 'yolo'] },
+      { args: ['node', 'script.js', '--yolo'] },
+    ];
+
+    for (const testCase of testCases) {
+      process.argv = testCase.args;
+      const argv = await parseArguments();
+      const settings: Settings = {};
+      const extensions: Extension[] = [];
+
+      const config = await loadCliConfig(
+        settings,
+        extensions,
+        'test-session',
+        argv,
+      );
+
+      const excludedTools = config.getExcludeTools();
+      expect(excludedTools).not.toContain(ShellTool.Name);
+      expect(excludedTools).not.toContain(EditTool.Name);
+      expect(excludedTools).not.toContain(WriteFileTool.Name);
+    }
+  });
+
+  it('should merge approval mode exclusions with settings exclusions in auto_edit mode', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--approval-mode',
+      'auto_edit',
+      '-p',
+      'test',
+    ];
+    const argv = await parseArguments();
+    const settings: Settings = { excludeTools: ['custom_tool'] };
+    const extensions: Extension[] = [];
+
+    const config = await loadCliConfig(
+      settings,
+      extensions,
+      'test-session',
+      argv,
+    );
+
+    const excludedTools = config.getExcludeTools();
+    expect(excludedTools).toContain('custom_tool'); // From settings
+    expect(excludedTools).toContain(ShellTool.Name); // From approval mode
+    expect(excludedTools).not.toContain(EditTool.Name); // Should be allowed in auto_edit
+    expect(excludedTools).not.toContain(WriteFileTool.Name); // Should be allowed in auto_edit
+  });
+
+  it('should throw an error for invalid approval mode values in loadCliConfig', async () => {
+    // Create a mock argv with an invalid approval mode that bypasses argument parsing validation
+    const invalidArgv: Partial<CliArgs> & { approvalMode: string } = {
+      approvalMode: 'invalid_mode',
+      promptInteractive: '',
+      prompt: '',
+      yolo: false,
+    };
+
+    const settings: Settings = {};
+    const extensions: Extension[] = [];
+
+    await expect(
+      loadCliConfig(settings, extensions, 'test-session', invalidArgv),
+    ).rejects.toThrow(
+      'Invalid approval mode: invalid_mode. Valid values are: yolo, auto_edit, default',
+    );
+  });
+});
+
 describe('loadCliConfig with allowed-mcp-server-names', () => {
   const originalArgv = process.argv;
   const originalEnv = { ...process.env };
@@ -1327,3 +1619,80 @@ describe('loadCliConfig interactive', () => {
     expect(config.isInteractive()).toBe(false);
   });
 });
+
+describe('loadCliConfig approval mode', () => {
+  const originalArgv = process.argv;
+  const originalEnv = { ...process.env };
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+    vi.mocked(os.homedir).mockReturnValue('/mock/home/user');
+    process.env.GEMINI_API_KEY = 'test-api-key';
+  });
+
+  afterEach(() => {
+    process.argv = originalArgv;
+    process.env = originalEnv;
+    vi.restoreAllMocks();
+  });
+
+  it('should default to DEFAULT approval mode when no flags are set', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.DEFAULT);
+  });
+
+  it('should set YOLO approval mode when --yolo flag is used', async () => {
+    process.argv = ['node', 'script.js', '--yolo'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.YOLO);
+  });
+
+  it('should set YOLO approval mode when -y flag is used', async () => {
+    process.argv = ['node', 'script.js', '-y'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.YOLO);
+  });
+
+  it('should set DEFAULT approval mode when --approval-mode=default', async () => {
+    process.argv = ['node', 'script.js', '--approval-mode', 'default'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.DEFAULT);
+  });
+
+  it('should set AUTO_EDIT approval mode when --approval-mode=auto_edit', async () => {
+    process.argv = ['node', 'script.js', '--approval-mode', 'auto_edit'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.AUTO_EDIT);
+  });
+
+  it('should set YOLO approval mode when --approval-mode=yolo', async () => {
+    process.argv = ['node', 'script.js', '--approval-mode', 'yolo'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.YOLO);
+  });
+
+  it('should prioritize --approval-mode over --yolo when both would be valid (but validation prevents this)', async () => {
+    // Note: This test documents the intended behavior, but in practice the validation
+    // prevents both flags from being used together
+    process.argv = ['node', 'script.js', '--approval-mode', 'default'];
+    const argv = await parseArguments();
+    // Manually set yolo to true to simulate what would happen if validation didn't prevent it
+    argv.yolo = true;
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.DEFAULT);
+  });
+
+  it('should fall back to --yolo behavior when --approval-mode is not set', async () => {
+    process.argv = ['node', 'script.js', '--yolo'];
+    const argv = await parseArguments();
+    const config = await loadCliConfig({}, [], 'test-session', argv);
+    expect(config.getApprovalMode()).toBe(ServerConfig.ApprovalMode.YOLO);
+  });
+});
diff --git a/packages/cli/src/config/config.ts b/packages/cli/src/config/config.ts
index d0658e75..dd207ff2 100644
--- a/packages/cli/src/config/config.ts
+++ b/packages/cli/src/config/config.ts
@@ -57,6 +57,7 @@ export interface CliArgs {
   showMemoryUsage: boolean | undefined;
   show_memory_usage: boolean | undefined;
   yolo: boolean | undefined;
+  approvalMode: string | undefined;
   telemetry: boolean | undefined;
   checkpointing: boolean | undefined;
   telemetryTarget: string | undefined;
@@ -147,6 +148,12 @@ export async function parseArguments(): Promise<CliArgs> {
             'Automatically accept all actions (aka YOLO mode, see https://www.youtube.com/watch?v=xvFZjo5PgG0 for more details)?',
           default: false,
         })
+        .option('approval-mode', {
+          type: 'string',
+          choices: ['default', 'auto_edit', 'yolo'],
+          description:
+            'Set the approval mode: default (prompt for approval), auto_edit (auto-approve edit tools), yolo (auto-approve all tools)',
+        })
         .option('telemetry', {
           type: 'boolean',
           description:
@@ -219,6 +226,11 @@ export async function parseArguments(): Promise<CliArgs> {
               'Cannot use both --prompt (-p) and --prompt-interactive (-i) together',
             );
           }
+          if (argv.yolo && argv.approvalMode) {
+            throw new Error(
+              'Cannot use both --yolo (-y) and --approval-mode together. Use --approval-mode=yolo instead.',
+            );
+          }
           return true;
         }),
     )
@@ -356,20 +368,59 @@ export async function loadCliConfig(
 
   let mcpServers = mergeMcpServers(settings, activeExtensions);
   const question = argv.promptInteractive || argv.prompt || '';
-  const approvalMode =
-    argv.yolo || false ? ApprovalMode.YOLO : ApprovalMode.DEFAULT;
+
+  // Determine approval mode with backward compatibility
+  let approvalMode: ApprovalMode;
+  if (argv.approvalMode) {
+    // New --approval-mode flag takes precedence
+    switch (argv.approvalMode) {
+      case 'yolo':
+        approvalMode = ApprovalMode.YOLO;
+        break;
+      case 'auto_edit':
+        approvalMode = ApprovalMode.AUTO_EDIT;
+        break;
+      case 'default':
+        approvalMode = ApprovalMode.DEFAULT;
+        break;
+      default:
+        throw new Error(
+          `Invalid approval mode: ${argv.approvalMode}. Valid values are: yolo, auto_edit, default`,
+        );
+    }
+  } else {
+    // Fallback to legacy --yolo flag behavior
+    approvalMode =
+      argv.yolo || false ? ApprovalMode.YOLO : ApprovalMode.DEFAULT;
+  }
+
   const interactive =
     !!argv.promptInteractive || (process.stdin.isTTY && question.length === 0);
-  // In non-interactive and non-yolo mode, exclude interactive built in tools.
-  const extraExcludes =
-    !interactive && approvalMode !== ApprovalMode.YOLO
-      ? [ShellTool.Name, EditTool.Name, WriteFileTool.Name]
-      : undefined;
+  // In non-interactive mode, exclude tools that require a prompt.
+  const extraExcludes: string[] = [];
+  if (!interactive) {
+    switch (approvalMode) {
+      case ApprovalMode.DEFAULT:
+        // In default non-interactive mode, all tools that require approval are excluded.
+        extraExcludes.push(ShellTool.Name, EditTool.Name, WriteFileTool.Name);
+        break;
+      case ApprovalMode.AUTO_EDIT:
+        // In auto-edit non-interactive mode, only tools that still require a prompt are excluded.
+        extraExcludes.push(ShellTool.Name);
+        break;
+      case ApprovalMode.YOLO:
+        // No extra excludes for YOLO mode.
+        break;
+      default:
+        // This should never happen due to validation earlier, but satisfies the linter
+        break;
+    }
+  }
 
   const excludeTools = mergeExcludeTools(
     settings,
     activeExtensions,
-    extraExcludes,
+    extraExcludes.length > 0 ? extraExcludes : undefined,
   );
   const blockedMcpServers: Array<{ name: string; extensionName: string }> = [];