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

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,