refactor: deprecate legacy confirmation settings and enforce Policy Engine (#15626)

docs/cli/settings.md

@@ -94,7 +94,6 @@ they appear in the UI.
 | Enable Tool Output Truncation    | `tools.enableToolOutputTruncation`   | Enable truncation of large tool outputs.                                                                        | `true`  |
 | Tool Output Truncation Threshold | `tools.truncateToolOutputThreshold`  | Truncate tool output if it is larger than this many characters. Set to -1 to disable.                           | `10000` |
 | Tool Output Truncation Lines     | `tools.truncateToolOutputLines`      | The number of lines to keep when truncating tool output.                                                        | `100`   |
-| Enable Message Bus Integration   | `tools.enableMessageBusIntegration`  | Enable policy-based tool confirmation via message bus integration.                                              | `true`  |
 
 ### Security
 

docs/get-started/configuration.md

@@ -684,14 +684,6 @@ their corresponding top-level category object in your `settings.json` file.
   - **Default:** `1000`
   - **Requires restart:** Yes
 
-- **`tools.enableMessageBusIntegration`** (boolean):
-  - **Description:** Enable policy-based tool confirmation via message bus
-    integration. When enabled, tools automatically respect policy engine
-    decisions (ALLOW/DENY/ASK_USER) without requiring individual tool
-    implementations.
-  - **Default:** `true`
-  - **Requires restart:** Yes
-
 - **`tools.enableHooks`** (boolean):
   - **Description:** Enable the hooks system for intercepting and customizing
     Gemini CLI behavior. When enabled, hooks configured in settings will execute

packages/a2a-server/src/utils/testing_utils.ts

@@ -59,7 +59,6 @@ export function createMockConfig(
     getEmbeddingModel: vi.fn().mockReturnValue('text-embedding-004'),
     getSessionId: vi.fn().mockReturnValue('test-session-id'),
     getUserTier: vi.fn(),
-    getEnableMessageBusIntegration: vi.fn().mockReturnValue(false),
     getMessageBus: vi.fn(),
     getPolicyEngine: vi.fn(),
     getEnableExtensionReloading: vi.fn().mockReturnValue(false),

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

@@ -16,6 +16,7 @@ import {
   WEB_FETCH_TOOL_NAME,
   type ExtensionLoader,
   debugLogger,
+  ApprovalMode,
 } from '@google/gemini-cli-core';
 import { loadCliConfig, parseArguments, type CliArgs } from './config.js';
 import type { Settings } from './settings.js';
@@ -629,14 +630,7 @@ describe('loadCliConfig', () => {
     expect(config.getFileFilteringRespectGeminiIgnore()).toBe(
       DEFAULT_FILE_FILTERING_OPTIONS.respectGeminiIgnore,
     );
-  });
-
-  it('should default enableMessageBusIntegration to true when unconfigured', async () => {
-    process.argv = ['node', 'script.js'];
-    const argv = await parseArguments({} as Settings);
-    const settings: Settings = {};
-    const config = await loadCliConfig(settings, 'test-session', argv);
-    expect(config['enableMessageBusIntegration']).toBe(true);
+    expect(config.getApprovalMode()).toBe(ApprovalMode.DEFAULT);
   });
 });
 

packages/cli/src/config/config.ts

@@ -542,9 +542,6 @@ export async function loadCliConfig(
     approvalMode,
   );
 
-  const enableMessageBusIntegration =
-    settings.tools?.enableMessageBusIntegration ?? true;
-
   const allowedTools = argv.allowedTools || settings.tools?.allowed || [];
   const allowedToolsSet = new Set(allowedTools);
 
@@ -695,7 +692,6 @@ export async function loadCliConfig(
     output: {
       format: (argv.outputFormat ?? settings.output?.format) as OutputFormat,
     },
-    enableMessageBusIntegration,
     codebaseInvestigatorSettings:
       settings.experimental?.codebaseInvestigatorSettings,
     introspectionAgentSettings:

packages/cli/src/config/settings.ts

@@ -85,7 +85,6 @@ const MIGRATION_MAP: Record<string, string> = {
   disableAutoUpdate: 'general.disableAutoUpdate',
   disableUpdateNag: 'general.disableUpdateNag',
   dnsResolutionOrder: 'advanced.dnsResolutionOrder',
-  enableMessageBusIntegration: 'tools.enableMessageBusIntegration',
   enableHooks: 'tools.enableHooks',
   enablePromptCompletion: 'general.enablePromptCompletion',
   enforcedAuthType: 'security.auth.enforcedType',

packages/cli/src/config/settingsSchema.ts

@@ -1073,18 +1073,6 @@ const SETTINGS_SCHEMA = {
         description: 'The number of lines to keep when truncating tool output.',
         showInDialog: true,
       },
-      enableMessageBusIntegration: {
-        type: 'boolean',
-        label: 'Enable Message Bus Integration',
-        category: 'Tools',
-        requiresRestart: true,
-        default: true,
-        description: oneLine`
-          Enable policy-based tool confirmation via message bus integration.
-          When enabled, tools automatically respect policy engine decisions (ALLOW/DENY/ASK_USER) without requiring individual tool implementations.
-        `,
-        showInDialog: true,
-      },
       enableHooks: {
         type: 'boolean',
         label: 'Enable Hooks System',

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

@@ -150,7 +150,7 @@ describe('Settings Repro', () => {
           showColor: true,
           enableInteractiveShell: true,
         },
-        enableMessageBusIntegration: true,
+        truncateToolOutputLines: 100,
       },
       experimental: {
         useModelRouter: false,

packages/cli/src/services/BuiltinCommandLoader.test.ts

@@ -96,7 +96,6 @@ describe('BuiltinCommandLoader', () => {
     vi.clearAllMocks();
     mockConfig = {
       getFolderTrust: vi.fn().mockReturnValue(true),
-      getEnableMessageBusIntegration: () => false,
       getEnableExtensionReloading: () => false,
       getEnableHooks: () => false,
     } as unknown as Config;
@@ -172,7 +171,6 @@ describe('BuiltinCommandLoader', () => {
   it('should include policies command when message bus integration is enabled', async () => {
     const mockConfigWithMessageBus = {
       ...mockConfig,
-      getEnableMessageBusIntegration: () => true,
       getEnableHooks: () => false,
     } as unknown as Config;
     const loader = new BuiltinCommandLoader(mockConfigWithMessageBus);
@@ -180,18 +178,6 @@ describe('BuiltinCommandLoader', () => {
     const policiesCmd = commands.find((c) => c.name === 'policies');
     expect(policiesCmd).toBeDefined();
   });
-
-  it('should exclude policies command when message bus integration is disabled', async () => {
-    const mockConfigWithoutMessageBus = {
-      ...mockConfig,
-      getEnableMessageBusIntegration: () => false,
-      getEnableHooks: () => false,
-    } as unknown as Config;
-    const loader = new BuiltinCommandLoader(mockConfigWithoutMessageBus);
-    const commands = await loader.loadCommands(new AbortController().signal);
-    const policiesCmd = commands.find((c) => c.name === 'policies');
-    expect(policiesCmd).toBeUndefined();
-  });
 });
 
 describe('BuiltinCommandLoader profile', () => {
@@ -202,7 +188,6 @@ describe('BuiltinCommandLoader profile', () => {
     mockConfig = {
       getFolderTrust: vi.fn().mockReturnValue(false),
       getCheckpointingEnabled: () => false,
-      getEnableMessageBusIntegration: () => false,
       getEnableExtensionReloading: () => false,
       getEnableHooks: () => false,
     } as unknown as Config;

packages/cli/src/services/BuiltinCommandLoader.ts

@@ -81,9 +81,7 @@ export class BuiltinCommandLoader implements ICommandLoader {
       modelCommand,
       ...(this.config?.getFolderTrust() ? [permissionsCommand] : []),
       privacyCommand,
-      ...(this.config?.getEnableMessageBusIntegration()
-        ? [policiesCommand]
-        : []),
+      policiesCommand,
       ...(isDevelopment ? [profileCommand] : []),
       quitCommand,
       restoreCommand(this.config),

packages/cli/src/ui/hooks/useToolScheduler.test.ts

@@ -80,7 +80,6 @@ const mockConfig = {
   getUseSmartEdit: () => false,
   getGeminiClient: () => null, // No client needed for these tests
   getShellExecutionConfig: () => ({ terminalWidth: 80, terminalHeight: 24 }),
-  getEnableMessageBusIntegration: () => false,
   getMessageBus: () => null,
   getPolicyEngine: () => null,
   isInteractive: () => false,

packages/core/src/config/config.test.ts

@@ -61,6 +61,7 @@ vi.mock('../tools/tool-registry', () => {
   ToolRegistryMock.prototype.sortTools = vi.fn();
   ToolRegistryMock.prototype.getAllTools = vi.fn(() => []); // Mock methods if needed
   ToolRegistryMock.prototype.getTool = vi.fn();
+  ToolRegistryMock.prototype.setMessageBus = vi.fn();
   ToolRegistryMock.prototype.getFunctionDeclarations = vi.fn(() => []);
   return { ToolRegistry: ToolRegistryMock };
 });
@@ -923,7 +924,7 @@ describe('Server Config (config.ts)', () => {
       expect(DelegateToAgentToolMock).toHaveBeenCalledWith(
         expect.anything(), // AgentRegistry
         config,
-        undefined,
+        expect.anything(), // MessageBus
       );
 
       const calls = registerToolMock.mock.calls;

packages/core/src/config/config.ts

@@ -312,7 +312,6 @@ export interface ConfigParameters {
   useWriteTodos?: boolean;
   policyEngineConfig?: PolicyEngineConfig;
   output?: OutputSettings;
-  enableMessageBusIntegration?: boolean;
   disableModelRouterForAuth?: AuthType[];
   codebaseInvestigatorSettings?: CodebaseInvestigatorSettings;
   introspectionAgentSettings?: IntrospectionAgentSettings;
@@ -436,7 +435,6 @@ export class Config {
   private readonly messageBus: MessageBus;
   private readonly policyEngine: PolicyEngine;
   private readonly outputSettings: OutputSettings;
-  private readonly enableMessageBusIntegration: boolean;
   private readonly codebaseInvestigatorSettings: CodebaseInvestigatorSettings;
   private readonly introspectionAgentSettings: IntrospectionAgentSettings;
   private readonly continueOnFailedApiCall: boolean;
@@ -579,14 +577,6 @@ export class Config {
         ? params.hooks.disabled
         : undefined) ?? [];
 
-    // Enable MessageBus integration if:
-    // 1. Explicitly enabled via setting, OR
-    // 2. Hooks are enabled and hooks are configured
-    const hasHooks = params.hooks && Object.keys(params.hooks).length > 0;
-    const hooksNeedMessageBus = this.enableHooks && hasHooks;
-    this.enableMessageBusIntegration =
-      params.enableMessageBusIntegration ??
-      (hooksNeedMessageBus ? true : false);
     this.codebaseInvestigatorSettings = {
       enabled: params.codebaseInvestigatorSettings?.enabled ?? true,
       maxNumTurns: params.codebaseInvestigatorSettings?.maxNumTurns ?? 10,
@@ -1580,10 +1570,6 @@ export class Config {
     return this.policyEngine;
   }
 
-  getEnableMessageBusIntegration(): boolean {
-    return this.enableMessageBusIntegration;
-  }
-
   getEnableHooks(): boolean {
     return this.enableHooks;
   }
@@ -1600,9 +1586,7 @@ export class Config {
     const registry = new ToolRegistry(this);
 
     // Set message bus on tool registry before discovery so MCP tools can access it
-    if (this.getEnableMessageBusIntegration()) {
-      registry.setMessageBus(this.messageBus);
-    }
+    registry.setMessageBus(this.messageBus);
 
     // helper to create & register core tools that are enabled
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -1628,11 +1612,7 @@ export class Config {
         // Pass message bus to tools when feature flag is enabled
         // This first implementation is only focused on the general case of
         // the tool registry.
-        const messageBusEnabled = this.getEnableMessageBusIntegration();
-
-        const toolArgs = messageBusEnabled
-          ? [...args, this.getMessageBus()]
-          : args;
+        const toolArgs = [...args, this.getMessageBus()];
 
         registry.registerTool(new ToolClass(...toolArgs));
       }
@@ -1686,11 +1666,10 @@ export class Config {
         !allowedTools || allowedTools.includes(DELEGATE_TO_AGENT_TOOL_NAME);
 
       if (isAllowed) {
-        const messageBusEnabled = this.getEnableMessageBusIntegration();
         const delegateTool = new DelegateToAgentTool(
           this.agentRegistry,
           this,
-          messageBusEnabled ? this.getMessageBus() : undefined,
+          this.getMessageBus(),
         );
         registry.registerTool(delegateTool);
       }

packages/core/src/core/coreToolScheduler.test.ts

@@ -257,8 +257,7 @@ function createMockConfig(overrides: Partial<Config> = {}): Config {
     getActiveModel: () => DEFAULT_GEMINI_MODEL,
     getUseSmartEdit: () => false,
     getGeminiClient: () => null,
-    getEnableMessageBusIntegration: () => false,
-    getMessageBus: () => null,
+    getMessageBus: () => createMockMessageBus(),
     getEnableHooks: () => false,
     getPolicyEngine: () => null,
     getExperiments: () => {},

packages/core/src/core/coreToolScheduler.ts

@@ -148,32 +148,30 @@ export class CoreToolScheduler {
     // Use a static WeakMap to ensure we only subscribe ONCE per MessageBus instance
     // This prevents memory leaks when multiple CoreToolScheduler instances are created
     // (e.g., on every React render, or for each non-interactive tool call)
-    if (this.config.getEnableMessageBusIntegration()) {
-      const messageBus = this.config.getMessageBus();
+    const messageBus = this.config.getMessageBus();
 
-      // Check if we've already subscribed a handler to this message bus
-      if (!CoreToolScheduler.subscribedMessageBuses.has(messageBus)) {
-        // Create a shared handler that will be used for this message bus
-        const sharedHandler = (request: ToolConfirmationRequest) => {
-          // When ASK_USER policy decision is made, respond with requiresUserConfirmation=true
-          // to tell tools to use their legacy confirmation flow
-          // eslint-disable-next-line @typescript-eslint/no-floating-promises
-          messageBus.publish({
-            type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
-            correlationId: request.correlationId,
-            confirmed: false,
-            requiresUserConfirmation: true,
-          });
-        };
+    // Check if we've already subscribed a handler to this message bus
+    if (!CoreToolScheduler.subscribedMessageBuses.has(messageBus)) {
+      // Create a shared handler that will be used for this message bus
+      const sharedHandler = (request: ToolConfirmationRequest) => {
+        // When ASK_USER policy decision is made, respond with requiresUserConfirmation=true
+        // to tell tools to use their legacy confirmation flow
+        // eslint-disable-next-line @typescript-eslint/no-floating-promises
+        messageBus.publish({
+          type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+          correlationId: request.correlationId,
+          confirmed: false,
+          requiresUserConfirmation: true,
+        });
+      };
 
-        messageBus.subscribe(
-          MessageBusType.TOOL_CONFIRMATION_REQUEST,
-          sharedHandler,
-        );
+      messageBus.subscribe(
+        MessageBusType.TOOL_CONFIRMATION_REQUEST,
+        sharedHandler,
+      );
 
-        // Store the handler in the WeakMap so we don't subscribe again
-        CoreToolScheduler.subscribedMessageBuses.set(messageBus, sharedHandler);
-      }
+      // Store the handler in the WeakMap so we don't subscribe again
+      CoreToolScheduler.subscribedMessageBuses.set(messageBus, sharedHandler);
     }
   }
 

packages/core/src/core/nonInteractiveToolExecutor.test.ts

@@ -65,7 +65,6 @@ describe('executeToolCall', () => {
       getActiveModel: () => PREVIEW_GEMINI_MODEL,
       getUseSmartEdit: () => false,
       getGeminiClient: () => null, // No client needed for these tests
-      getEnableMessageBusIntegration: () => false,
       getMessageBus: () => null,
       getPolicyEngine: () => null,
       isInteractive: () => false,

schemas/settings.schema.json

@@ -1128,13 +1128,6 @@
           "default": 1000,
           "type": "number"
         },
-        "enableMessageBusIntegration": {
-          "title": "Enable Message Bus Integration",
-          "description": "Enable policy-based tool confirmation via message bus integration. When enabled, tools automatically respect policy engine decisions (ALLOW/DENY/ASK_USER) without requiring individual tool implementations.",
-          "markdownDescription": "Enable policy-based tool confirmation via message bus integration. When enabled, tools automatically respect policy engine decisions (ALLOW/DENY/ASK_USER) without requiring individual tool implementations.\n\n- Category: `Tools`\n- Requires restart: `yes`\n- Default: `true`",
-          "default": true,
-          "type": "boolean"
-        },
         "enableHooks": {
           "title": "Enable Hooks System",
           "description": "Enable the hooks system for intercepting and customizing Gemini CLI behavior. When enabled, hooks configured in settings will execute at appropriate lifecycle events (BeforeTool, AfterTool, BeforeModel, etc.). Requires MessageBus integration.",