feat(a2a): add agent acknowledgment command and enhance registry discovery (#22389)

packages/a2a-server/src/config/config.test.ts

@@ -19,6 +19,8 @@ import {
   AuthType,
   isHeadlessMode,
   FatalAuthenticationError,
+  PolicyDecision,
+  PRIORITY_YOLO_ALLOW_ALL,
 } from '@google/gemini-cli-core';
 
 // Mock dependencies
@@ -325,6 +327,29 @@ describe('loadConfig', () => {
       );
     });
 
+    it('should pass enableAgents to Config constructor', async () => {
+      const settings: Settings = {
+        experimental: {
+          enableAgents: false,
+        },
+      };
+      await loadConfig(settings, mockExtensionLoader, taskId);
+      expect(Config).toHaveBeenCalledWith(
+        expect.objectContaining({
+          enableAgents: false,
+        }),
+      );
+    });
+
+    it('should default enableAgents to true when not provided', async () => {
+      await loadConfig(mockSettings, mockExtensionLoader, taskId);
+      expect(Config).toHaveBeenCalledWith(
+        expect.objectContaining({
+          enableAgents: true,
+        }),
+      );
+    });
+
     describe('interactivity', () => {
       it('should set interactive true when not headless', async () => {
         vi.mocked(isHeadlessMode).mockReturnValue(false);
@@ -349,6 +374,41 @@ describe('loadConfig', () => {
       });
     });
 
+    describe('YOLO mode', () => {
+      it('should enable YOLO mode and add policy rule when GEMINI_YOLO_MODE is true', async () => {
+        vi.stubEnv('GEMINI_YOLO_MODE', 'true');
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+        expect(Config).toHaveBeenCalledWith(
+          expect.objectContaining({
+            approvalMode: 'yolo',
+            policyEngineConfig: expect.objectContaining({
+              rules: expect.arrayContaining([
+                expect.objectContaining({
+                  decision: PolicyDecision.ALLOW,
+                  priority: PRIORITY_YOLO_ALLOW_ALL,
+                  modes: ['yolo'],
+                  allowRedirection: true,
+                }),
+              ]),
+            }),
+          }),
+        );
+      });
+
+      it('should use default approval mode and empty rules when GEMINI_YOLO_MODE is not true', async () => {
+        vi.stubEnv('GEMINI_YOLO_MODE', 'false');
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+        expect(Config).toHaveBeenCalledWith(
+          expect.objectContaining({
+            approvalMode: 'default',
+            policyEngineConfig: expect.objectContaining({
+              rules: [],
+            }),
+          }),
+        );
+      });
+    });
+
     describe('authentication fallback', () => {
       beforeEach(() => {
         vi.stubEnv('USE_CCPA', 'true');

packages/a2a-server/src/config/config.ts

@@ -26,6 +26,8 @@ import {
   isHeadlessMode,
   FatalAuthenticationError,
   isCloudShell,
+  PolicyDecision,
+  PRIORITY_YOLO_ALLOW_ALL,
   type TelemetryTarget,
   type ConfigParameters,
   type ExtensionLoader,
@@ -60,6 +62,11 @@ export async function loadConfig(
     }
   }
 
+  const approvalMode =
+    process.env['GEMINI_YOLO_MODE'] === 'true'
+      ? ApprovalMode.YOLO
+      : ApprovalMode.DEFAULT;
+
   const configParams: ConfigParameters = {
     sessionId: taskId,
     clientName: 'a2a-server',
@@ -74,10 +81,20 @@ export async function loadConfig(
     excludeTools: settings.excludeTools || settings.tools?.exclude || undefined,
     allowedTools: settings.allowedTools || settings.tools?.allowed || undefined,
     showMemoryUsage: settings.showMemoryUsage || false,
-    approvalMode:
-      process.env['GEMINI_YOLO_MODE'] === 'true'
-        ? ApprovalMode.YOLO
-        : ApprovalMode.DEFAULT,
+    approvalMode,
+    policyEngineConfig: {
+      rules:
+        approvalMode === ApprovalMode.YOLO
+          ? [
+              {
+                decision: PolicyDecision.ALLOW,
+                priority: PRIORITY_YOLO_ALLOW_ALL,
+                modes: [ApprovalMode.YOLO],
+                allowRedirection: true,
+              },
+            ]
+          : [],
+    },
     mcpServers: settings.mcpServers,
     cwd: workspaceDir,
     telemetry: {
@@ -110,6 +127,7 @@ export async function loadConfig(
     interactive: !isHeadlessMode(),
     enableInteractiveShell: !isHeadlessMode(),
     ptyInfo: 'auto',
+    enableAgents: settings.experimental?.enableAgents ?? true,
   };
 
   const fileService = new FileDiscoveryService(workspaceDir, {

packages/a2a-server/src/config/settings.test.ts

@@ -112,6 +112,18 @@ describe('loadSettings', () => {
     expect(result.fileFiltering?.respectGitIgnore).toBe(true);
   });
 
+  it('should load experimental settings correctly', () => {
+    const settings = {
+      experimental: {
+        enableAgents: true,
+      },
+    };
+    fs.writeFileSync(USER_SETTINGS_PATH, JSON.stringify(settings));
+
+    const result = loadSettings(mockWorkspaceDir);
+    expect(result.experimental?.enableAgents).toBe(true);
+  });
+
   it('should overwrite top-level settings from workspace (shallow merge)', () => {
     const userSettings = {
       showMemoryUsage: false,

packages/a2a-server/src/config/settings.ts

@@ -48,6 +48,9 @@ export interface Settings {
     enableRecursiveFileSearch?: boolean;
     customIgnoreFilePaths?: string[];
   };
+  experimental?: {
+    enableAgents?: boolean;
+  };
 }
 
 export interface SettingsError {