Merge remote-tracking branch 'origin/main' into fix/agent-loader-error-formatting

# Conflicts:
#	packages/core/src/agents/agentLoader.ts

# Conflicts:
#	packages/core/src/agents/agentLoader.ts

docs/reference/configuration.md

@@ -1540,7 +1540,7 @@ their corresponding top-level category object in your `settings.json` file.
 
 - **`experimental.enableAgents`** (boolean):
   - **Description:** Enable local and remote subagents.
-  - **Default:** `false`
+  - **Default:** `true`
   - **Requires restart:** Yes
 
 - **`experimental.worktrees`** (boolean):

integration-tests/browser-policy.test.ts

@@ -63,9 +63,6 @@ describe.skipIf(!chromeAvailable)('browser-policy', () => {
     rig.setup('browser-policy-skip-confirmation', {
       fakeResponsesPath: join(__dirname, 'browser-policy.responses'),
       settings: {
-        experimental: {
-          enableAgents: true,
-        },
         agents: {
           overrides: {
             browser_agent: {
@@ -183,9 +180,6 @@ priority = 200
     rig.setup('browser-session-warning', {
       fakeResponsesPath: join(__dirname, 'browser-agent.cleanup.responses'),
       settings: {
-        experimental: {
-          enableAgents: true,
-        },
         general: {
           enableAutoUpdateNotification: false,
         },

integration-tests/ctrl-c-exit.test.ts

@@ -6,9 +6,9 @@
 
 import { describe, it, expect, beforeEach, afterEach } from 'vitest';
 import * as os from 'node:os';
-import { TestRig } from './test-helper.js';
+import { TestRig, skipFlaky } from './test-helper.js';
 
-describe('Ctrl+C exit', () => {
+describe.skipIf(skipFlaky)('Ctrl+C exit', () => {
   let rig: TestRig;
 
   beforeEach(() => {

integration-tests/plan-mode.test.ts

@@ -4,10 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { writeFileSync } from 'node:fs';
-import { join } from 'node:path';
 import { describe, it, expect, beforeEach, afterEach } from 'vitest';
-import { TestRig, checkModelOutputContent, GEMINI_DIR } from './test-helper.js';
+import { TestRig, checkModelOutputContent } from './test-helper.js';
 
 describe('Plan Mode', () => {
   let rig: TestRig;
@@ -36,27 +34,23 @@ describe('Plan Mode', () => {
       },
     );
 
-    // We use a prompt that asks for both a read-only action and a write action.
-    // "List files" (read-only) followed by "touch denied.txt" (write).
     const result = await rig.run({
       approvalMode: 'plan',
-      stdin:
-        'Please list the files in the current directory, and then attempt to create a new file named "denied.txt" using a shell command.',
+      args: 'Please list the files in the current directory, and then attempt to create a new file named "denied.txt" using a shell command.',
     });
 
-    const lsCallFound = await rig.waitForToolCall('list_directory');
-    expect(lsCallFound, 'Expected list_directory to be called').toBe(true);
-
-    const shellCallFound = await rig.waitForToolCall('run_shell_command');
-    expect(shellCallFound, 'Expected run_shell_command to fail').toBe(false);
-
     const toolLogs = rig.readToolLogs();
     const lsLog = toolLogs.find((l) => l.toolRequest.name === 'list_directory');
-    expect(
-      toolLogs.find((l) => l.toolRequest.name === 'run_shell_command'),
-    ).toBeUndefined();
+    const shellLog = toolLogs.find(
+      (l) => l.toolRequest.name === 'run_shell_command',
+    );
 
+    expect(lsLog, 'Expected list_directory to be called').toBeDefined();
     expect(lsLog?.toolRequest.success).toBe(true);
+    expect(
+      shellLog,
+      'Expected run_shell_command to be blocked (not even called)',
+    ).toBeUndefined();
 
     checkModelOutputContent(result, {
       expectedContent: ['Plan Mode', 'read-only'],
@@ -84,23 +78,11 @@ describe('Plan Mode', () => {
       },
     });
 
-    // Disable the interactive terminal setup prompt in tests
-    writeFileSync(
-      join(rig.homeDir!, GEMINI_DIR, 'state.json'),
-      JSON.stringify({ terminalSetupPromptShown: true }, null, 2),
-    );
-
-    const run = await rig.runInteractive({
+    await rig.run({
       approvalMode: 'plan',
+      args: 'Create a file called plan.md in the plans directory.',
     });
 
-    await run.type('Create a file called plan.md in the plans directory.');
-    await run.type('\r');
-
-    await rig.expectToolCallSuccess(['write_file'], 30000, (args) =>
-      args.includes('plan.md'),
-    );
-
     const toolLogs = rig.readToolLogs();
     const planWrite = toolLogs.find(
       (l) =>
@@ -108,7 +90,25 @@ describe('Plan Mode', () => {
         l.toolRequest.args.includes('plans') &&
         l.toolRequest.args.includes('plan.md'),
     );
-    expect(planWrite?.toolRequest.success).toBe(true);
+
+    if (!planWrite) {
+      console.error(
+        'All tool calls found:',
+        toolLogs.map((l) => ({
+          name: l.toolRequest.name,
+          args: l.toolRequest.args,
+        })),
+      );
+    }
+
+    expect(
+      planWrite,
+      'Expected write_file to be called for plan.md',
+    ).toBeDefined();
+    expect(
+      planWrite?.toolRequest.success,
+      `Expected write_file to succeed, but it failed with error: ${planWrite?.toolRequest.error}`,
+    ).toBe(true);
   });
 
   it('should deny write_file to non-plans directory in plan mode', async () => {
@@ -131,19 +131,11 @@ describe('Plan Mode', () => {
       },
     });
 
-    // Disable the interactive terminal setup prompt in tests
-    writeFileSync(
-      join(rig.homeDir!, GEMINI_DIR, 'state.json'),
-      JSON.stringify({ terminalSetupPromptShown: true }, null, 2),
-    );
-
-    const run = await rig.runInteractive({
+    await rig.run({
       approvalMode: 'plan',
+      args: 'Create a file called hello.txt in the current directory.',
     });
 
-    await run.type('Create a file called hello.txt in the current directory.');
-    await run.type('\r');
-
     const toolLogs = rig.readToolLogs();
     const writeLog = toolLogs.find(
       (l) =>
@@ -151,10 +143,11 @@ describe('Plan Mode', () => {
         l.toolRequest.args.includes('hello.txt'),
     );
 
-    // In Plan Mode, writes outside the plans directory should be blocked.
-    // Model is undeterministic, sometimes it doesn't even try, but if it does, it must fail.
     if (writeLog) {
-      expect(writeLog.toolRequest.success).toBe(false);
+      expect(
+        writeLog.toolRequest.success,
+        'Expected write_file to non-plans dir to fail',
+      ).toBe(false);
     }
   });
 
@@ -169,28 +162,69 @@ describe('Plan Mode', () => {
       },
     });
 
-    // Disable the interactive terminal setup prompt in tests
-    writeFileSync(
-      join(rig.homeDir!, GEMINI_DIR, 'state.json'),
-      JSON.stringify({ terminalSetupPromptShown: true }, null, 2),
-    );
-
-    // Start in default mode and ask to enter plan mode.
     await rig.run({
       approvalMode: 'default',
-      stdin:
-        'I want to perform a complex refactoring. Please enter plan mode so we can design it first.',
+      args: 'I want to perform a complex refactoring. Please enter plan mode so we can design it first.',
     });
 
-    const enterPlanCallFound = await rig.waitForToolCall('enter_plan_mode');
-    expect(enterPlanCallFound, 'Expected enter_plan_mode to be called').toBe(
-      true,
-    );
-
     const toolLogs = rig.readToolLogs();
     const enterLog = toolLogs.find(
       (l) => l.toolRequest.name === 'enter_plan_mode',
     );
+    expect(enterLog, 'Expected enter_plan_mode to be called').toBeDefined();
     expect(enterLog?.toolRequest.success).toBe(true);
   });
+
+  it('should allow write_file to the plans directory in plan mode even without a session ID', async () => {
+    const plansDir = '.gemini/tmp/foo/plans';
+    const testName =
+      'should allow write_file to the plans directory in plan mode even without a session ID';
+
+    await rig.setup(testName, {
+      settings: {
+        experimental: { plan: true },
+        tools: {
+          core: ['write_file', 'read_file', 'list_directory'],
+        },
+        general: {
+          defaultApprovalMode: 'plan',
+          plan: {
+            directory: plansDir,
+          },
+        },
+      },
+    });
+
+    await rig.run({
+      approvalMode: 'plan',
+      args: 'Create a file called plan-no-session.md in the plans directory.',
+    });
+
+    const toolLogs = rig.readToolLogs();
+    const planWrite = toolLogs.find(
+      (l) =>
+        l.toolRequest.name === 'write_file' &&
+        l.toolRequest.args.includes('plans') &&
+        l.toolRequest.args.includes('plan-no-session.md'),
+    );
+
+    if (!planWrite) {
+      console.error(
+        'All tool calls found:',
+        toolLogs.map((l) => ({
+          name: l.toolRequest.name,
+          args: l.toolRequest.args,
+        })),
+      );
+    }
+
+    expect(
+      planWrite,
+      'Expected write_file to be called for plan-no-session.md',
+    ).toBeDefined();
+    expect(
+      planWrite?.toolRequest.success,
+      `Expected write_file to succeed, but it failed with error: ${planWrite?.toolRequest.error}`,
+    ).toBe(true);
+  });
 });

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@google/gemini-cli",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@google/gemini-cli",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "workspaces": [
         "packages/*"
       ],
@@ -17413,7 +17413,7 @@
     },
     "packages/a2a-server": {
       "name": "@google/gemini-cli-a2a-server",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "dependencies": {
         "@a2a-js/sdk": "0.3.11",
         "@google-cloud/storage": "^7.16.0",
@@ -17528,7 +17528,7 @@
     },
     "packages/cli": {
       "name": "@google/gemini-cli",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "license": "Apache-2.0",
       "dependencies": {
         "@agentclientprotocol/sdk": "^0.16.1",
@@ -17700,7 +17700,7 @@
     },
     "packages/core": {
       "name": "@google/gemini-cli-core",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "license": "Apache-2.0",
       "dependencies": {
         "@a2a-js/sdk": "0.3.11",
@@ -17966,7 +17966,7 @@
     },
     "packages/devtools": {
       "name": "@google/gemini-cli-devtools",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "license": "Apache-2.0",
       "dependencies": {
         "ws": "^8.16.0"
@@ -17981,7 +17981,7 @@
     },
     "packages/sdk": {
       "name": "@google/gemini-cli-sdk",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "license": "Apache-2.0",
       "dependencies": {
         "@google/gemini-cli-core": "file:../core",
@@ -17998,7 +17998,7 @@
     },
     "packages/test-utils": {
       "name": "@google/gemini-cli-test-utils",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "license": "Apache-2.0",
       "dependencies": {
         "@google/gemini-cli-core": "file:../core",
@@ -18015,7 +18015,7 @@
     },
     "packages/vscode-ide-companion": {
       "name": "gemini-cli-vscode-ide-companion",
-      "version": "0.36.0-nightly.20260317.2f90b4653",
+      "version": "0.36.0-preview.3",
       "license": "LICENSE",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.23.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "engines": {
     "node": ">=20.0.0"
   },
@@ -14,7 +14,7 @@
     "url": "git+https://github.com/google-gemini/gemini-cli.git"
   },
   "config": {
-    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.36.0-nightly.20260317.2f90b4653"
+    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.36.0-preview.3"
   },
   "scripts": {
     "start": "cross-env NODE_ENV=development node scripts/start.js",

packages/a2a-server/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-a2a-server",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "description": "Gemini CLI A2A Server",
   "repository": {
     "type": "git",

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

@@ -29,6 +29,7 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
     await importOriginal<typeof import('@google/gemini-cli-core')>();
   return {
     ...actual,
+    PRIORITY_YOLO_ALLOW_ALL: 998,
     Config: vi.fn().mockImplementation((params) => {
       const mockConfig = {
         ...params,
@@ -341,11 +342,11 @@ describe('loadConfig', () => {
       );
     });
 
-    it('should default enableAgents to false when not provided', async () => {
+    it('should default enableAgents to true when not provided', async () => {
       await loadConfig(mockSettings, mockExtensionLoader, taskId);
       expect(Config).toHaveBeenCalledWith(
         expect.objectContaining({
-          enableAgents: false,
+          enableAgents: true,
         }),
       );
     });

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

@@ -128,7 +128,7 @@ export async function loadConfig(
     interactive: !isHeadlessMode(),
     enableInteractiveShell: !isHeadlessMode(),
     ptyInfo: 'auto',
-    enableAgents: settings.experimental?.enableAgents ?? false,
+    enableAgents: settings.experimental?.enableAgents ?? true,
   };
 
   const fileService = new FileDiscoveryService(workspaceDir, {

packages/cli/index.ts

@@ -6,19 +6,12 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-// --- Fast Path for Version ---
-// We check for version flags at the very top to avoid loading any heavy dependencies.
-// process.env.CLI_VERSION is defined during the build process by esbuild.
-if (process.argv.includes('--version') || process.argv.includes('-v')) {
-  console.log(process.env['CLI_VERSION'] || 'unknown');
-  process.exit(0);
-}
+import { main } from './src/gemini.js';
+import { FatalError, writeToStderr } from '@google/gemini-cli-core';
+import { runExitCleanup } from './src/utils/cleanup.js';
 
 // --- Global Entry Point ---
 
-let writeToStderrFn: (message: string) => void = (msg) =>
-  process.stderr.write(msg);
-
 // Suppress known race condition error in node-pty on Windows
 // Tracking bug: https://github.com/microsoft/node-pty/issues/827
 process.on('uncaughtException', (error) => {
@@ -35,22 +28,13 @@ process.on('uncaughtException', (error) => {
   // For other errors, we rely on the default behavior, but since we attached a listener,
   // we must manually replicate it.
   if (error instanceof Error) {
-    writeToStderrFn(error.stack + '\n');
+    writeToStderr(error.stack + '\n');
   } else {
-    writeToStderrFn(String(error) + '\n');
+    writeToStderr(String(error) + '\n');
   }
   process.exit(1);
 });
 
-const [{ main }, { FatalError, writeToStderr }, { runExitCleanup }] =
-  await Promise.all([
-    import('./src/gemini.js'),
-    import('@google/gemini-cli-core'),
-    import('./src/utils/cleanup.js'),
-  ]);
-
-writeToStderrFn = writeToStderr;
-
 main().catch(async (error) => {
   // Set a timeout to force exit if cleanup hangs
   const cleanupTimeout = setTimeout(() => {

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "description": "Gemini CLI",
   "license": "Apache-2.0",
   "repository": {
@@ -27,7 +27,7 @@
     "dist"
   ],
   "config": {
-    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.36.0-nightly.20260317.2f90b4653"
+    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.36.0-preview.3"
   },
   "dependencies": {
     "@agentclientprotocol/sdk": "^0.16.1",

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

@@ -400,7 +400,7 @@ describe('SettingsSchema', () => {
       expect(setting).toBeDefined();
       expect(setting.type).toBe('boolean');
       expect(setting.category).toBe('Experimental');
-      expect(setting.default).toBe(false);
+      expect(setting.default).toBe(true);
       expect(setting.requiresRestart).toBe(true);
       expect(setting.showInDialog).toBe(false);
       expect(setting.description).toBe('Enable local and remote subagents.');

packages/cli/src/config/settingsSchema.ts

@@ -1932,7 +1932,7 @@ const SETTINGS_SCHEMA = {
         label: 'Enable Agents',
         category: 'Experimental',
         requiresRestart: true,
-        default: false,
+        default: true,
         description: 'Enable local and remote subagents.',
         showInDialog: false,
       },

packages/core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-core",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "description": "Gemini CLI Core",
   "license": "Apache-2.0",
   "repository": {

packages/core/src/agents/a2a-client-manager.test.ts

@@ -128,7 +128,10 @@ describe('A2AClientManager', () => {
 
   describe('getInstance / dispatcher initialization', () => {
     it('should use UndiciAgent when no proxy is configured', async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
 
       const resolverOptions = vi.mocked(DefaultAgentCardResolver).mock
         .calls[0][0];
@@ -153,7 +156,10 @@ describe('A2AClientManager', () => {
       } as Config;
 
       manager = new A2AClientManager(mockConfigWithProxy);
-      await manager.loadAgent('TestProxyAgent', 'http://test.proxy.agent/card');
+      await manager.loadAgent('TestProxyAgent', {
+        type: 'url',
+        url: 'http://test.proxy.agent/card',
+      });
 
       const resolverOptions = vi.mocked(DefaultAgentCardResolver).mock
         .calls[0][0];
@@ -172,28 +178,40 @@ describe('A2AClientManager', () => {
 
   describe('loadAgent', () => {
     it('should create and cache an A2AClient', async () => {
-      const agentCard = await manager.loadAgent(
-        'TestAgent',
-        'http://test.agent/card',
-      );
+      const agentCard = await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
       expect(manager.getAgentCard('TestAgent')).toBe(agentCard);
       expect(manager.getClient('TestAgent')).toBeDefined();
     });
 
     it('should configure ClientFactory with REST, JSON-RPC, and gRPC transports', async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
       expect(ClientFactoryOptions.createFrom).toHaveBeenCalled();
     });
 
     it('should throw an error if an agent with the same name is already loaded', async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
       await expect(
-        manager.loadAgent('TestAgent', 'http://test.agent/card'),
+        manager.loadAgent('TestAgent', {
+          type: 'url',
+          url: 'http://test.agent/card',
+        }),
       ).rejects.toThrow("Agent with name 'TestAgent' is already loaded.");
     });
 
     it('should use native fetch by default', async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
       expect(createAuthenticatingFetchWithRetry).not.toHaveBeenCalled();
     });
 
@@ -204,7 +222,7 @@ describe('A2AClientManager', () => {
       };
       await manager.loadAgent(
         'TestAgent',
-        'http://test.agent/card',
+        { type: 'url', url: 'http://test.agent/card' },
         customAuthHandler as unknown as AuthenticationHandler,
       );
 
@@ -221,7 +239,7 @@ describe('A2AClientManager', () => {
       };
       await manager.loadAgent(
         'AuthCardAgent',
-        'http://authcard.agent/card',
+        { type: 'url', url: 'http://authcard.agent/card' },
         customAuthHandler as unknown as AuthenticationHandler,
       );
 
@@ -252,7 +270,7 @@ describe('A2AClientManager', () => {
 
       await manager.loadAgent(
         'AuthCardAgent401',
-        'http://authcard.agent/card',
+        { type: 'url', url: 'http://authcard.agent/card' },
         customAuthHandler as unknown as AuthenticationHandler,
       );
 
@@ -267,19 +285,65 @@ describe('A2AClientManager', () => {
     });
 
     it('should log a debug message upon loading an agent', async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
       expect(debugLogger.debug).toHaveBeenCalledWith(
         expect.stringContaining("Loaded agent 'TestAgent'"),
       );
     });
 
     it('should clear the cache', async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
       manager.clearCache();
       expect(manager.getAgentCard('TestAgent')).toBeUndefined();
       expect(manager.getClient('TestAgent')).toBeUndefined();
     });
 
+    it('should load an agent from inline JSON without calling resolver', async () => {
+      const inlineJson = JSON.stringify(mockAgentCard);
+      const agentCard = await manager.loadAgent('JsonAgent', {
+        type: 'json',
+        json: inlineJson,
+      });
+      expect(agentCard).toBeDefined();
+      expect(agentCard.name).toBe('test-agent');
+      expect(manager.getAgentCard('JsonAgent')).toBe(agentCard);
+      expect(manager.getClient('JsonAgent')).toBeDefined();
+      // Resolver should not have been called for inline JSON
+      const resolverInstance = vi.mocked(DefaultAgentCardResolver).mock
+        .results[0]?.value;
+      if (resolverInstance) {
+        expect(resolverInstance.resolve).not.toHaveBeenCalled();
+      }
+    });
+
+    it('should throw a descriptive error for invalid inline JSON', async () => {
+      await expect(
+        manager.loadAgent('BadJsonAgent', {
+          type: 'json',
+          json: 'not valid json {{',
+        }),
+      ).rejects.toThrow(
+        /Failed to parse inline agent card JSON for agent 'BadJsonAgent'/,
+      );
+    });
+
+    it('should log "inline JSON" for JSON-loaded agents', async () => {
+      const inlineJson = JSON.stringify(mockAgentCard);
+      await manager.loadAgent('JsonLogAgent', {
+        type: 'json',
+        json: inlineJson,
+      });
+      expect(debugLogger.debug).toHaveBeenCalledWith(
+        expect.stringContaining('inline JSON'),
+      );
+    });
+
     it('should throw if resolveAgentCard fails', async () => {
       const resolverInstance = {
         resolve: vi.fn().mockRejectedValue(new Error('Resolution failed')),
@@ -289,7 +353,10 @@ describe('A2AClientManager', () => {
       );
 
       await expect(
-        manager.loadAgent('FailAgent', 'http://fail.agent'),
+        manager.loadAgent('FailAgent', {
+          type: 'url',
+          url: 'http://fail.agent',
+        }),
       ).rejects.toThrow('Resolution failed');
     });
 
@@ -304,7 +371,10 @@ describe('A2AClientManager', () => {
       );
 
       await expect(
-        manager.loadAgent('FailAgent', 'http://fail.agent'),
+        manager.loadAgent('FailAgent', {
+          type: 'url',
+          url: 'http://fail.agent',
+        }),
       ).rejects.toThrow('Factory failed');
     });
   });
@@ -318,7 +388,10 @@ describe('A2AClientManager', () => {
 
   describe('sendMessageStream', () => {
     beforeEach(async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
     });
 
     it('should send a message and return a stream', async () => {
@@ -433,7 +506,10 @@ describe('A2AClientManager', () => {
 
   describe('getTask', () => {
     beforeEach(async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
     });
 
     it('should get a task from the correct agent', async () => {
@@ -462,7 +538,10 @@ describe('A2AClientManager', () => {
 
   describe('cancelTask', () => {
     beforeEach(async () => {
-      await manager.loadAgent('TestAgent', 'http://test.agent/card');
+      await manager.loadAgent('TestAgent', {
+        type: 'url',
+        url: 'http://test.agent/card',
+      });
     });
 
     it('should cancel a task on the correct agent', async () => {

packages/core/src/agents/a2a-client-manager.ts

@@ -26,6 +26,7 @@ import * as grpc from '@grpc/grpc-js';
 import { v4 as uuidv4 } from 'uuid';
 import { Agent as UndiciAgent, ProxyAgent } from 'undici';
 import { normalizeAgentCard } from './a2aUtils.js';
+import type { AgentCardLoadOptions } from './types.js';
 import type { Config } from '../config/config.js';
 import { debugLogger } from '../utils/debugLogger.js';
 import { classifyAgentError } from './a2a-errors.js';
@@ -85,7 +86,7 @@ export class A2AClientManager {
    */
   async loadAgent(
     name: string,
-    agentCardUrl: string,
+    options: AgentCardLoadOptions,
     authHandler?: AuthenticationHandler,
   ): Promise<AgentCard> {
     if (this.clients.has(name) && this.agentCards.has(name)) {
@@ -119,7 +120,24 @@ export class A2AClientManager {
     };
 
     const resolver = new DefaultAgentCardResolver({ fetchImpl: cardFetch });
-    const rawCard = await resolver.resolve(agentCardUrl, '');
+
+    let rawCard: unknown;
+    let urlIdentifier = 'inline JSON';
+
+    if (options.type === 'json') {
+      try {
+        rawCard = JSON.parse(options.json);
+      } catch (error) {
+        const msg = error instanceof Error ? error.message : String(error);
+        throw new Error(
+          `Failed to parse inline agent card JSON for agent '${name}': ${msg}`,
+        );
+      }
+    } else {
+      urlIdentifier = options.url;
+      rawCard = await resolver.resolve(options.url, '');
+    }
+
     // TODO: Remove normalizeAgentCard once @a2a-js/sdk handles
     // proto field name aliases (supportedInterfaces → additionalInterfaces,
     // protocolBinding → transport).
@@ -153,12 +171,12 @@ export class A2AClientManager {
       this.agentCards.set(name, agentCard);
 
       debugLogger.debug(
-        `[A2AClientManager] Loaded agent '${name}' from ${agentCardUrl}`,
+        `[A2AClientManager] Loaded agent '${name}' from ${urlIdentifier}`,
       );
 
       return agentCard;
     } catch (error: unknown) {
-      throw classifyAgentError(name, agentCardUrl, error);
+      throw classifyAgentError(name, urlIdentifier, error);
     }
   }
 

packages/core/src/agents/agentLoader.test.ts

@@ -19,6 +19,9 @@ import {
   DEFAULT_MAX_TIME_MINUTES,
   DEFAULT_MAX_TURNS,
   type LocalAgentDefinition,
+  type RemoteAgentDefinition,
+  getAgentCardLoadOptions,
+  getRemoteAgentTargetUrl,
 } from './types.js';
 
 describe('loader', () => {
@@ -232,6 +235,75 @@ agent_card_url: https://example.com/card
       });
     });
 
+    it('should parse a remote agent with agent_card_json', async () => {
+      const cardJson = JSON.stringify({
+        name: 'json-agent',
+        url: 'https://example.com/agent',
+        version: '1.0',
+      });
+      const filePath = await writeAgentMarkdown(`---
+kind: remote
+name: json-remote
+description: A JSON-based remote agent
+agent_card_json: '${cardJson}'
+---
+`);
+      const result = await parseAgentMarkdown(filePath);
+      expect(result).toHaveLength(1);
+      expect(result[0]).toMatchObject({
+        kind: 'remote',
+        name: 'json-remote',
+        description: 'A JSON-based remote agent',
+        agent_card_json: cardJson,
+      });
+      // Should NOT have agent_card_url
+      expect(result[0]).not.toHaveProperty('agent_card_url');
+    });
+
+    it('should reject agent_card_json that is not valid JSON', async () => {
+      const filePath = await writeAgentMarkdown(`---
+kind: remote
+name: invalid-json-remote
+agent_card_json: "not valid json {{"
+---
+`);
+      await expect(parseAgentMarkdown(filePath)).rejects.toThrow(
+        /agent_card_json must be valid JSON/,
+      );
+    });
+
+    it('should reject a remote agent with both agent_card_url and agent_card_json', async () => {
+      const filePath = await writeAgentMarkdown(`---
+kind: remote
+name: both-fields
+agent_card_url: https://example.com/card
+agent_card_json: '{"name":"test"}'
+---
+`);
+      await expect(parseAgentMarkdown(filePath)).rejects.toThrow(
+        /Validation failed/,
+      );
+    });
+
+    it('should infer remote kind from agent_card_json', async () => {
+      const cardJson = JSON.stringify({
+        name: 'test',
+        url: 'https://example.com',
+      });
+      const filePath = await writeAgentMarkdown(`---
+name: inferred-json-remote
+agent_card_json: '${cardJson}'
+---
+`);
+      const result = await parseAgentMarkdown(filePath);
+      expect(result).toHaveLength(1);
+      expect(result[0]).toMatchObject({
+        kind: 'remote',
+        name: 'inferred-json-remote',
+        agent_card_json: cardJson,
+      });
+    });
+
     it('should throw AgentLoadError if agent name is not a valid slug', async () => {
       const filePath = await writeAgentMarkdown(`---
 name: Invalid Name With Spaces
@@ -242,6 +314,99 @@ Body`);
         /Name must be a valid slug/,
       );
     });
+
+    describe('error formatting and kind inference', () => {
+      it('should only show local agent errors when kind is inferred as local (via kind field)', async () => {
+        const filePath = await writeAgentMarkdown(`---
+kind: local
+name: invalid-local
+# missing description
+---
+Body`);
+        const error = await parseAgentMarkdown(filePath).catch((e) => e);
+        expect(error).toBeInstanceOf(AgentLoadError);
+        expect(error.message).toContain('Validation failed');
+        expect(error.message).toContain('description: Required');
+        expect(error.message).not.toContain('Remote Agent');
+      });
+
+      it('should only show local agent errors when kind is inferred as local (via local-specific keys)', async () => {
+        const filePath = await writeAgentMarkdown(`---
+name: invalid-local
+# missing description
+tools:
+  - run_shell_command
+---
+Body`);
+        const error = await parseAgentMarkdown(filePath).catch((e) => e);
+        expect(error).toBeInstanceOf(AgentLoadError);
+        expect(error.message).toContain('Validation failed');
+        expect(error.message).toContain('description: Required');
+        expect(error.message).not.toContain('Remote Agent');
+      });
+
+      it('should only show remote agent errors when kind is inferred as remote (via kind field)', async () => {
+        const filePath = await writeAgentMarkdown(`---
+kind: remote
+name: invalid-remote
+# missing agent_card_url
+---
+Body`);
+        const error = await parseAgentMarkdown(filePath).catch((e) => e);
+        expect(error).toBeInstanceOf(AgentLoadError);
+        expect(error.message).toContain('Validation failed');
+        expect(error.message).toContain('agent_card_url: Required');
+        expect(error.message).not.toContain('Local Agent');
+      });
+
+      it('should only show remote agent errors when kind is inferred as remote (via remote-specific keys)', async () => {
+        const filePath = await writeAgentMarkdown(`---
+name: invalid-remote
+auth:
+  type: apiKey
+  key: my_key
+# missing agent_card_url
+---
+Body`);
+        const error = await parseAgentMarkdown(filePath).catch((e) => e);
+        expect(error).toBeInstanceOf(AgentLoadError);
+        expect(error.message).toContain('Validation failed');
+        expect(error.message).toContain('agent_card_url: Required');
+        expect(error.message).not.toContain('Local Agent');
+      });
+
+      it('should show errors for both types when kind cannot be inferred', async () => {
+        const filePath = await writeAgentMarkdown(`---
+name: invalid-unknown
+# missing description and missing agent_card_url, no specific keys
+---
+Body`);
+        const error = await parseAgentMarkdown(filePath).catch((e) => e);
+        expect(error).toBeInstanceOf(AgentLoadError);
+        expect(error.message).toContain('Validation failed');
+        expect(error.message).toContain('(Local Agent)');
+        expect(error.message).toContain('(Remote Agent)');
+        expect(error.message).toContain('description: Required');
+        expect(error.message).toContain('agent_card_url: Required');
+      });
+
+      it('should format errors without a stray colon when the path is empty (e.g. strict object with unknown keys)', async () => {
+        const filePath = await writeAgentMarkdown(`---
+kind: local
+name: my-agent
+description: test
+unknown_field: true
+---
+Body`);
+        const error = await parseAgentMarkdown(filePath).catch((e) => e);
+        expect(error).toBeInstanceOf(AgentLoadError);
+        expect(error.message).toContain(
+          "Unrecognized key(s) in object: 'unknown_field'",
+        );
+        expect(error.message).not.toContain(': Unrecognized key(s)');
+        expect(error.message).not.toContain('Required');
+      });
+    });
   });
 
   describe('markdownToAgentDefinition', () => {
@@ -372,6 +537,40 @@ Body`);
         },
       });
     });
+
+    it('should convert remote agent definition with agent_card_json', () => {
+      const cardJson = JSON.stringify({
+        name: 'json-agent',
+        url: 'https://example.com/agent',
+      });
+      const markdown = {
+        kind: 'remote' as const,
+        name: 'json-remote',
+        description: 'A JSON remote agent',
+        agent_card_json: cardJson,
+      };
+
+      const result = markdownToAgentDefinition(
+        markdown,
+      ) as RemoteAgentDefinition;
+      expect(result.kind).toBe('remote');
+      expect(result.name).toBe('json-remote');
+      expect(result.agentCardJson).toBe(cardJson);
+      expect(result.agentCardUrl).toBeUndefined();
+    });
+
+    it('should throw for remote agent with neither agent_card_url nor agent_card_json', () => {
+      // Cast to bypass compile-time check — this tests the runtime guard
+      const markdown = {
+        kind: 'remote' as const,
+        name: 'no-card-agent',
+        description: 'Missing card info',
+      } as Parameters<typeof markdownToAgentDefinition>[0];
+
+      expect(() => markdownToAgentDefinition(markdown)).toThrow(
+        /neither agent_card_json nor agent_card_url/,
+      );
+    });
   });
 
   describe('loadAgentsFromDirectory', () => {
@@ -744,5 +943,103 @@ auth:
         },
       });
     });
+
+    it('should throw an error for an unknown auth type in markdownToAgentDefinition', () => {
+      const markdown = {
+        kind: 'remote' as const,
+        name: 'unknown-auth-agent',
+        agent_card_url: 'https://example.com/card',
+        auth: {
+          type: 'apiKey' as const,
+          key: 'some-key',
+        },
+      };
+
+      // Mutate the object at runtime to bypass TypeScript compile-time checks cleanly
+      Object.assign(markdown.auth, { type: 'some-unknown-type' });
+
+      expect(() => markdownToAgentDefinition(markdown)).toThrow(
+        /Unknown auth type: some-unknown-type/,
+      );
+    });
+  });
+
+  describe('getAgentCardLoadOptions', () => {
+    it('should return json options when agentCardJson is present', () => {
+      const def = {
+        name: 'test',
+        agentCardJson: '{"url":"http://x"}',
+      } as RemoteAgentDefinition;
+      const opts = getAgentCardLoadOptions(def);
+      expect(opts).toEqual({ type: 'json', json: '{"url":"http://x"}' });
+    });
+
+    it('should return url options when agentCardUrl is present', () => {
+      const def = {
+        name: 'test',
+        agentCardUrl: 'http://x/card',
+      } as RemoteAgentDefinition;
+      const opts = getAgentCardLoadOptions(def);
+      expect(opts).toEqual({ type: 'url', url: 'http://x/card' });
+    });
+
+    it('should prefer agentCardJson over agentCardUrl when both present', () => {
+      const def = {
+        name: 'test',
+        agentCardJson: '{"url":"http://x"}',
+        agentCardUrl: 'http://x/card',
+      } as RemoteAgentDefinition;
+      const opts = getAgentCardLoadOptions(def);
+      expect(opts.type).toBe('json');
+    });
+
+    it('should throw when neither is present', () => {
+      const def = { name: 'orphan' } as RemoteAgentDefinition;
+      expect(() => getAgentCardLoadOptions(def)).toThrow(
+        /Remote agent 'orphan' has neither agentCardUrl nor agentCardJson/,
+      );
+    });
+  });
+
+  describe('getRemoteAgentTargetUrl', () => {
+    it('should return agentCardUrl when present', () => {
+      const def = {
+        name: 'test',
+        agentCardUrl: 'http://x/card',
+      } as RemoteAgentDefinition;
+      expect(getRemoteAgentTargetUrl(def)).toBe('http://x/card');
+    });
+
+    it('should extract url from agentCardJson when agentCardUrl is absent', () => {
+      const def = {
+        name: 'test',
+        agentCardJson: JSON.stringify({
+          name: 'agent',
+          url: 'https://example.com/agent',
+        }),
+      } as RemoteAgentDefinition;
+      expect(getRemoteAgentTargetUrl(def)).toBe('https://example.com/agent');
+    });
+
+    it('should return undefined when JSON has no url field', () => {
+      const def = {
+        name: 'test',
+        agentCardJson: JSON.stringify({ name: 'agent' }),
+      } as RemoteAgentDefinition;
+      expect(getRemoteAgentTargetUrl(def)).toBeUndefined();
+    });
+
+    it('should return undefined when agentCardJson is invalid JSON', () => {
+      const def = {
+        name: 'test',
+        agentCardJson: 'not json',
+      } as RemoteAgentDefinition;
+      expect(getRemoteAgentTargetUrl(def)).toBeUndefined();
+    });
+
+    it('should return undefined when neither field is present', () => {
+      const def = { name: 'test' } as RemoteAgentDefinition;
+      expect(getRemoteAgentTargetUrl(def)).toBeUndefined();
+    });
   });
 });

packages/core/src/agents/agentLoader.ts

@@ -12,6 +12,7 @@ import * as crypto from 'node:crypto';
 import { z } from 'zod';
 import {
   type AgentDefinition,
+  type RemoteAgentDefinition,
   DEFAULT_MAX_TURNS,
   DEFAULT_MAX_TIME_MINUTES,
 } from './types.js';
@@ -21,79 +22,6 @@ import { isValidToolName } from '../tools/tool-names.js';
 import { FRONTMATTER_REGEX } from '../skills/skillLoader.js';
 import { getErrorMessage } from '../utils/errors.js';
 
-/**
- * DTO for Markdown parsing - represents the structure from frontmatter.
- */
-interface FrontmatterBaseAgentDefinition {
-  name: string;
-  display_name?: string;
-}
-
-interface FrontmatterMCPServerConfig {
-  command?: string;
-  args?: string[];
-  env?: Record<string, string>;
-  cwd?: string;
-  url?: string;
-  http_url?: string;
-  headers?: Record<string, string>;
-  tcp?: string;
-  type?: 'sse' | 'http';
-  timeout?: number;
-  trust?: boolean;
-  description?: string;
-  include_tools?: string[];
-  exclude_tools?: string[];
-}
-
-interface FrontmatterLocalAgentDefinition
-  extends FrontmatterBaseAgentDefinition {
-  kind: 'local';
-  description: string;
-  tools?: string[];
-  mcp_servers?: Record<string, FrontmatterMCPServerConfig>;
-  system_prompt: string;
-  model?: string;
-  temperature?: number;
-  max_turns?: number;
-  timeout_mins?: number;
-}
-
-/**
- * Authentication configuration for remote agents in frontmatter format.
- */
-interface FrontmatterAuthConfig {
-  type: 'apiKey' | 'http' | 'google-credentials' | 'oauth';
-  // API Key
-  key?: string;
-  name?: string;
-  // HTTP
-  scheme?: string;
-  token?: string;
-  username?: string;
-  password?: string;
-  value?: string;
-  // Google Credentials
-  scopes?: string[];
-  // OAuth2
-  client_id?: string;
-  client_secret?: string;
-  authorization_url?: string;
-  token_url?: string;
-}
-
-interface FrontmatterRemoteAgentDefinition
-  extends FrontmatterBaseAgentDefinition {
-  kind: 'remote';
-  description?: string;
-  agent_card_url: string;
-  auth?: FrontmatterAuthConfig;
-}
-
-type FrontmatterAgentDefinition =
-  | FrontmatterLocalAgentDefinition
-  | FrontmatterRemoteAgentDefinition;
-
 /**
  * Error thrown when an agent definition is invalid or cannot be loaded.
  */
@@ -159,15 +87,13 @@ const localAgentSchema = z
   })
   .strict();
 
-/**
- * Base fields shared by all auth configs.
- */
+type FrontmatterLocalAgentDefinition = z.infer<typeof localAgentSchema> & {
+  system_prompt: string;
+};
+
+// Base fields shared by all auth configs.
 const baseAuthFields = {};
 
-/**
- * API Key auth schema.
- * Supports sending key in header, query parameter, or cookie.
- */
 const apiKeyAuthSchema = z.object({
   ...baseAuthFields,
   type: z.literal('apiKey'),
@@ -175,11 +101,6 @@ const apiKeyAuthSchema = z.object({
   name: z.string().optional(),
 });
 
-/**
- * HTTP auth schema (Bearer or Basic).
- * Note: Validation for scheme-specific fields is applied in authConfigSchema
- * since discriminatedUnion doesn't support refined schemas directly.
- */
 const httpAuthSchema = z.object({
   ...baseAuthFields,
   type: z.literal('http'),
@@ -190,19 +111,12 @@ const httpAuthSchema = z.object({
   value: z.string().min(1).optional(),
 });
 
-/**
- * Google Credentials auth schema.
- */
 const googleCredentialsAuthSchema = z.object({
   ...baseAuthFields,
   type: z.literal('google-credentials'),
   scopes: z.array(z.string()).optional(),
 });
 
-/**
- * OAuth2 auth schema.
- * authorization_url and token_url can be discovered from the agent card if omitted.
- */
 const oauth2AuthSchema = z.object({
   ...baseAuthFields,
   type: z.literal('oauth'),
@@ -222,18 +136,16 @@ const authConfigSchema = z
   ])
   .superRefine((data, ctx) => {
     if (data.type === 'http') {
-      if (data.value) {
-        // Raw mode - only scheme and value are needed
-        return;
-      }
-      if (data.scheme === 'Bearer' && !data.token) {
-        ctx.addIssue({
-          code: z.ZodIssueCode.custom,
-          message: 'Bearer scheme requires "token"',
-          path: ['token'],
-        });
-      }
-      if (data.scheme === 'Basic') {
+      if (data.value) return;
+      if (data.scheme === 'Bearer') {
+        if (!data.token) {
+          ctx.addIssue({
+            code: z.ZodIssueCode.custom,
+            message: 'Bearer scheme requires "token"',
+            path: ['token'],
+          });
+        }
+      } else if (data.scheme === 'Basic') {
         if (!data.username) {
           ctx.addIssue({
             code: z.ZodIssueCode.custom,
@@ -248,55 +160,127 @@ const authConfigSchema = z
             path: ['password'],
           });
         }
+      } else {
+        ctx.addIssue({
+          code: z.ZodIssueCode.custom,
+          message: `HTTP scheme "${data.scheme}" requires "value"`,
+          path: ['value'],
+        });
       }
     }
   });
 
-const remoteAgentSchema = z
-  .object({
-    kind: z.literal('remote').optional().default('remote'),
-    name: nameSchema,
-    description: z.string().optional(),
-    display_name: z.string().optional(),
+type FrontmatterAuthConfig = z.infer<typeof authConfigSchema>;
+
+const baseRemoteAgentSchema = z.object({
+  kind: z.literal('remote').optional().default('remote'),
+  name: nameSchema,
+  description: z.string().optional(),
+  display_name: z.string().optional(),
+  auth: authConfigSchema.optional(),
+});
+
+const remoteAgentUrlSchema = baseRemoteAgentSchema
+  .extend({
     agent_card_url: z.string().url(),
-    auth: authConfigSchema.optional(),
+    agent_card_json: z.undefined().optional(),
   })
   .strict();
 
-// Use a Zod union to automatically discriminate between local and remote
-// agent types.
+const remoteAgentJsonSchema = baseRemoteAgentSchema
+  .extend({
+    agent_card_url: z.undefined().optional(),
+    agent_card_json: z.string().refine(
+      (val) => {
+        try {
+          JSON.parse(val);
+          return true;
+        } catch {
+          return false;
+        }
+      },
+      { message: 'agent_card_json must be valid JSON' },
+    ),
+  })
+  .strict();
+
+const remoteAgentSchema = z.union([
+  remoteAgentUrlSchema,
+  remoteAgentJsonSchema,
+]);
+type FrontmatterRemoteAgentDefinition = z.infer<typeof remoteAgentSchema>;
+
+type FrontmatterAgentDefinition =
+  | FrontmatterLocalAgentDefinition
+  | FrontmatterRemoteAgentDefinition;
+
 const agentUnionOptions = [
-  { schema: localAgentSchema, label: 'Local Agent' },
-  { schema: remoteAgentSchema, label: 'Remote Agent' },
-] as const;
+  { label: 'Local Agent' },
+  { label: 'Remote Agent' },
+  { label: 'Remote Agent' },
+];
 
 const remoteAgentsListSchema = z.array(remoteAgentSchema);
 
 const markdownFrontmatterSchema = z.union([
-  agentUnionOptions[0].schema,
-  agentUnionOptions[1].schema,
+  localAgentSchema,
+  remoteAgentUrlSchema,
+  remoteAgentJsonSchema,
 ]);
 
-function formatZodError(error: z.ZodError, context: string): string {
-  const issues = error.issues
-    .map((i) => {
-      // Handle union errors specifically to give better context
+function guessIntendedKind(rawInput: unknown): 'local' | 'remote' | undefined {
+  if (typeof rawInput !== 'object' || rawInput === null) return undefined;
+  const input = rawInput as Partial<FrontmatterLocalAgentDefinition> &
+    Partial<FrontmatterRemoteAgentDefinition>;
+
+  if (input.kind === 'local') return 'local';
+  if (input.kind === 'remote') return 'remote';
+
+  const hasLocalKeys =
+    'tools' in input ||
+    'mcp_servers' in input ||
+    'model' in input ||
+    'temperature' in input ||
+    'max_turns' in input ||
+    'timeout_mins' in input;
+  const hasRemoteKeys =
+    'agent_card_url' in input || 'auth' in input || 'agent_card_json' in input;
+
+  if (hasLocalKeys && !hasRemoteKeys) return 'local';
+  if (hasRemoteKeys && !hasLocalKeys) return 'remote';
+
+  return undefined;
+}
+
+function formatZodError(
+  error: z.ZodError,
+  context: string,
+  rawInput?: unknown,
+): string {
+  const intendedKind = rawInput ? guessIntendedKind(rawInput) : undefined;
+
+  const formatIssues = (issues: z.ZodIssue[], unionPrefix?: string): string[] =>
+    issues.flatMap((i) => {
       if (i.code === z.ZodIssueCode.invalid_union) {
-        return i.unionErrors
-          .map((unionError, index) => {
-            const label =
-              agentUnionOptions[index]?.label ?? `Agent type #${index + 1}`;
-            const unionIssues = unionError.issues
-              .map((u) => `${u.path.join('.')}: ${u.message}`)
-              .join(', ');
-            return `(${label}) ${unionIssues}`;
-          })
-          .join('\n');
+        return i.unionErrors.flatMap((unionError, index) => {
+          const label = unionPrefix
+            ? unionPrefix
+            : ((agentUnionOptions[index] as { label?: string })?.label ??
+              `Branch #${index + 1}`);
+
+          if (intendedKind === 'local' && label === 'Remote Agent') return [];
+          if (intendedKind === 'remote' && label === 'Local Agent') return [];
+
+          return formatIssues(unionError.issues, label);
+        });
       }
-      return `${i.path.join('.')}: ${i.message}`;
-    })
-    .join('\n');
-  return `${context}:\n${issues}`;
+      const prefix = unionPrefix ? `(${unionPrefix}) ` : '';
+      const path = i.path.length > 0 ? `${i.path.join('.')}: ` : '';
+      return `${prefix}${path}${i.message}`;
+    });
+
+  const formatted = Array.from(new Set(formatIssues(error.issues))).join('\n');
+  return `${context}:\n${formatted}`;
 }
 
 /**
@@ -343,8 +327,7 @@ export async function parseAgentMarkdown(
   } catch (error) {
     throw new AgentLoadError(
       filePath,
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-      `YAML frontmatter parsing failed: ${(error as Error).message}`,
+      `YAML frontmatter parsing failed: ${getErrorMessage(error)}`,
     );
   }
 
@@ -368,7 +351,7 @@ export async function parseAgentMarkdown(
   if (!result.success) {
     throw new AgentLoadError(
       filePath,
-      `Validation failed: ${formatZodError(result.error, 'Agent Definition')}`,
+      `Validation failed: ${formatZodError(result.error, 'Agent Definition', rawFrontmatter)}`,
     );
   }
 
@@ -383,17 +366,14 @@ export async function parseAgentMarkdown(
     ];
   }
 
-  // Local agent validation
-  // Validate tools
-
   // Construct the local agent definition
-  const agentDef: FrontmatterLocalAgentDefinition = {
-    ...frontmatter,
-    kind: 'local',
-    system_prompt: body.trim(),
-  };
-
-  return [agentDef];
+  return [
+    {
+      ...frontmatter,
+      kind: 'local',
+      system_prompt: body.trim(),
+    },
+  ];
 }
 
 /**
@@ -403,15 +383,9 @@ export async function parseAgentMarkdown(
 function convertFrontmatterAuthToConfig(
   frontmatter: FrontmatterAuthConfig,
 ): A2AAuthConfig {
-  const base = {};
-
   switch (frontmatter.type) {
     case 'apiKey':
-      if (!frontmatter.key) {
-        throw new Error('Internal error: API key missing after validation.');
-      }
       return {
-        ...base,
         type: 'apiKey',
         key: frontmatter.key,
         name: frontmatter.name,
@@ -419,20 +393,13 @@ function convertFrontmatterAuthToConfig(
 
     case 'google-credentials':
       return {
-        ...base,
         type: 'google-credentials',
         scopes: frontmatter.scopes,
       };
 
-    case 'http': {
-      if (!frontmatter.scheme) {
-        throw new Error(
-          'Internal error: HTTP scheme missing after validation.',
-        );
-      }
+    case 'http':
       if (frontmatter.value) {
         return {
-          ...base,
           type: 'http',
           scheme: frontmatter.scheme,
           value: frontmatter.value,
@@ -440,40 +407,27 @@ function convertFrontmatterAuthToConfig(
       }
       switch (frontmatter.scheme) {
         case 'Bearer':
-          if (!frontmatter.token) {
-            throw new Error(
-              'Internal error: Bearer token missing after validation.',
-            );
-          }
+          // Token is required by schema validation
           return {
-            ...base,
             type: 'http',
             scheme: 'Bearer',
-            token: frontmatter.token,
+
+            token: frontmatter.token!,
           };
         case 'Basic':
-          if (!frontmatter.username || !frontmatter.password) {
-            throw new Error(
-              'Internal error: Basic auth credentials missing after validation.',
-            );
-          }
+          // Username/password are required by schema validation
           return {
-            ...base,
             type: 'http',
             scheme: 'Basic',
-            username: frontmatter.username,
-            password: frontmatter.password,
+            username: frontmatter.username!,
+            password: frontmatter.password!,
           };
-        default: {
-          // Other IANA schemes without a value should not reach here after validation
+        default:
           throw new Error(`Unknown HTTP scheme: ${frontmatter.scheme}`);
-        }
       }
-    }
 
     case 'oauth':
       return {
-        ...base,
         type: 'oauth2',
         client_id: frontmatter.client_id,
         client_secret: frontmatter.client_secret,
@@ -483,8 +437,12 @@ function convertFrontmatterAuthToConfig(
       };
 
     default: {
-      const exhaustive: never = frontmatter.type;
-      throw new Error(`Unknown auth type: ${exhaustive}`);
+      const exhaustive: never = frontmatter;
+      const raw: unknown = exhaustive;
+      if (typeof raw === 'object' && raw !== null && 'type' in raw) {
+        throw new Error(`Unknown auth type: ${String(raw['type'])}`);
+      }
+      throw new Error('Unknown auth type');
     }
   }
 }
@@ -515,25 +473,41 @@ export function markdownToAgentDefinition(
   };
 
   if (markdown.kind === 'remote') {
-    return {
+    const base: RemoteAgentDefinition = {
       kind: 'remote',
       name: markdown.name,
       description: markdown.description || '',
       displayName: markdown.display_name,
-      agentCardUrl: markdown.agent_card_url,
       auth: markdown.auth
         ? convertFrontmatterAuthToConfig(markdown.auth)
         : undefined,
       inputConfig,
       metadata,
     };
+
+    if (
+      'agent_card_json' in markdown &&
+      markdown.agent_card_json !== undefined
+    ) {
+      base.agentCardJson = markdown.agent_card_json;
+      return base;
+    }
+    if ('agent_card_url' in markdown && markdown.agent_card_url !== undefined) {
+      base.agentCardUrl = markdown.agent_card_url;
+      return base;
+    }
+
+    throw new AgentLoadError(
+      metadata?.filePath || 'unknown',
+      'Unexpected state: neither agent_card_json nor agent_card_url present on remote agent',
+    );
   }
 
   // If a model is specified, use it. Otherwise, inherit
   const modelName = markdown.model || 'inherit';
 
   const mcpServers: Record<string, MCPServerConfig> = {};
-  if (markdown.kind === 'local' && markdown.mcp_servers) {
+  if (markdown.mcp_servers) {
     for (const [name, config] of Object.entries(markdown.mcp_servers)) {
       mcpServers[name] = new MCPServerConfig(
         config.command,
@@ -606,15 +580,13 @@ export async function loadAgentsFromDirectory(
     dirEntries = await fs.readdir(dir, { withFileTypes: true });
   } catch (error) {
     // If directory doesn't exist, just return empty
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-    if ((error as NodeJS.ErrnoException).code === 'ENOENT') {
+    if (error instanceof Error && 'code' in error && error.code === 'ENOENT') {
       return result;
     }
     result.errors.push(
       new AgentLoadError(
         dir,
-        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-        `Could not list directory: ${(error as Error).message}`,
+        `Could not list directory: ${getErrorMessage(error)}`,
       ),
     );
     return result;
@@ -644,8 +616,7 @@ export async function loadAgentsFromDirectory(
         result.errors.push(
           new AgentLoadError(
             filePath,
-            // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-            `Unexpected error: ${(error as Error).message}`,
+            `Unexpected error: ${getErrorMessage(error)}`,
           ),
         );
       }

packages/core/src/agents/registry.test.ts

@@ -596,7 +596,7 @@ describe('AgentRegistry', () => {
       });
       expect(loadAgentSpy).toHaveBeenCalledWith(
         'RemoteAgentWithAuth',
-        'https://example.com/card',
+        { type: 'url', url: 'https://example.com/card' },
         mockHandler,
       );
       expect(registry.getDefinition('RemoteAgentWithAuth')).toEqual(

packages/core/src/agents/registry.ts

@@ -4,10 +4,12 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import * as crypto from 'node:crypto';
 import { Storage } from '../config/storage.js';
 import { CoreEvent, coreEvents } from '../utils/events.js';
 import type { AgentOverride, Config } from '../config/config.js';
 import type { AgentDefinition, LocalAgentDefinition } from './types.js';
+import { getAgentCardLoadOptions, getRemoteAgentTargetUrl } from './types.js';
 import { loadAgentsFromDirectory } from './agentLoader.js';
 import { CodebaseInvestigatorAgent } from './codebase-investigator.js';
 import { CliHelpAgent } from './cli-help-agent.js';
@@ -162,7 +164,14 @@ export class AgentRegistry {
           if (!agent.metadata) {
             agent.metadata = {};
           }
-          agent.metadata.hash = agent.agentCardUrl;
+          agent.metadata.hash =
+            agent.agentCardUrl ??
+            (agent.agentCardJson
+              ? crypto
+                  .createHash('sha256')
+                  .update(agent.agentCardJson)
+                  .digest('hex')
+              : undefined);
         }
 
         if (!agent.metadata?.hash) {
@@ -443,12 +452,13 @@ export class AgentRegistry {
         );
         return;
       }
+      const targetUrl = getRemoteAgentTargetUrl(remoteDef);
       let authHandler: AuthenticationHandler | undefined;
       if (definition.auth) {
         const provider = await A2AAuthProviderFactory.create({
           authConfig: definition.auth,
           agentName: definition.name,
-          targetUrl: definition.agentCardUrl,
+          targetUrl,
           agentCardUrl: remoteDef.agentCardUrl,
         });
         if (!provider) {
@@ -461,7 +471,7 @@ export class AgentRegistry {
 
       const agentCard = await clientManager.loadAgent(
         remoteDef.name,
-        remoteDef.agentCardUrl,
+        getAgentCardLoadOptions(remoteDef),
         authHandler,
       );
 
@@ -515,7 +525,7 @@ export class AgentRegistry {
 
       if (this.config.getDebugMode()) {
         debugLogger.log(
-          `[AgentRegistry] Registered remote agent '${definition.name}' with card: ${definition.agentCardUrl}`,
+          `[AgentRegistry] Registered remote agent '${definition.name}' with card: ${definition.agentCardUrl ?? 'inline JSON'}`,
         );
       }
       this.agents.set(definition.name, definition);

packages/core/src/agents/remote-invocation.test.ts

@@ -189,7 +189,7 @@ describe('RemoteAgentInvocation', () => {
 
       expect(mockClientManager.loadAgent).toHaveBeenCalledWith(
         'test-agent',
-        'http://test-agent/card',
+        { type: 'url', url: 'http://test-agent/card' },
         undefined,
       );
     });
@@ -240,7 +240,7 @@ describe('RemoteAgentInvocation', () => {
       });
       expect(mockClientManager.loadAgent).toHaveBeenCalledWith(
         'test-agent',
-        'http://test-agent/card',
+        { type: 'url', url: 'http://test-agent/card' },
         mockHandler,
       );
     });
@@ -266,11 +266,10 @@ describe('RemoteAgentInvocation', () => {
       );
       const result = await invocation.execute(new AbortController().signal);
 
-      expect(result.returnDisplay).toMatchObject({
-        result: expect.stringContaining(
-          "Failed to create auth provider for agent 'test-agent'",
-        ),
-      });
+      expect(result.returnDisplay).toMatchObject({ state: 'error' });
+      expect((result.returnDisplay as SubagentProgress).result).toContain(
+        "Failed to create auth provider for agent 'test-agent'",
+      );
     });
 
     it('should not load the agent if already present', async () => {

packages/core/src/agents/remote-invocation.ts

@@ -16,6 +16,8 @@ import {
   type RemoteAgentDefinition,
   type AgentInputs,
   type SubagentProgress,
+  getAgentCardLoadOptions,
+  getRemoteAgentTargetUrl,
 } from './types.js';
 import { type AgentLoopContext } from '../config/agent-loop-context.js';
 import type { MessageBus } from '../confirmation-bus/message-bus.js';
@@ -92,10 +94,11 @@ export class RemoteAgentInvocation extends BaseToolInvocation<
     }
 
     if (this.definition.auth) {
+      const targetUrl = getRemoteAgentTargetUrl(this.definition);
       const provider = await A2AAuthProviderFactory.create({
         authConfig: this.definition.auth,
         agentName: this.definition.name,
-        targetUrl: this.definition.agentCardUrl,
+        targetUrl,
         agentCardUrl: this.definition.agentCardUrl,
       });
       if (!provider) {
@@ -162,7 +165,7 @@ export class RemoteAgentInvocation extends BaseToolInvocation<
       if (!this.clientManager.getClient(this.definition.name)) {
         await this.clientManager.loadAgent(
           this.definition.name,
-          this.definition.agentCardUrl,
+          getAgentCardLoadOptions(this.definition),
           authHandler,
         );
       }

packages/core/src/agents/types.ts

@@ -13,6 +13,7 @@ import type { AnyDeclarativeTool } from '../tools/tools.js';
 import { type z } from 'zod';
 import type { ModelConfig } from '../services/modelConfigService.js';
 import type { AnySchema } from 'ajv';
+import type { AgentCard } from '@a2a-js/sdk';
 import type { A2AAuthConfig } from './auth-provider/types.js';
 import type { MCPServerConfig } from '../config/config.js';
 
@@ -128,6 +129,62 @@ export function isToolActivityError(data: unknown): boolean {
  * The base definition for an agent.
  * @template TOutput The specific Zod schema for the agent's final output object.
  */
+export type AgentCardLoadOptions =
+  | { type: 'url'; url: string }
+  | { type: 'json'; json: string };
+
+/** Minimal shape needed by helper functions, avoids generic TOutput constraints. */
+interface RemoteAgentRef {
+  name: string;
+  agentCardUrl?: string;
+  agentCardJson?: string;
+}
+
+/**
+ * Derives the AgentCardLoadOptions from a RemoteAgentDefinition.
+ * Throws if neither agentCardUrl nor agentCardJson is present.
+ */
+export function getAgentCardLoadOptions(
+  def: RemoteAgentRef,
+): AgentCardLoadOptions {
+  if (def.agentCardJson) {
+    return { type: 'json', json: def.agentCardJson };
+  }
+  if (def.agentCardUrl) {
+    return { type: 'url', url: def.agentCardUrl };
+  }
+  throw new Error(
+    `Remote agent '${def.name}' has neither agentCardUrl nor agentCardJson`,
+  );
+}
+
+/**
+ * Extracts a target URL for auth providers from a RemoteAgentDefinition.
+ * For URL-based agents, returns the agentCardUrl.
+ * For JSON-based agents, attempts to parse the URL from the inline card JSON.
+ * Returns undefined if no URL can be determined.
+ */
+export function getRemoteAgentTargetUrl(
+  def: RemoteAgentRef,
+): string | undefined {
+  if (def.agentCardUrl) {
+    return def.agentCardUrl;
+  }
+  if (def.agentCardJson) {
+    try {
+      const parsed: unknown = JSON.parse(def.agentCardJson);
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      const card = parsed as AgentCard;
+      if (card.url) {
+        return card.url;
+      }
+    } catch {
+      // JSON parse will fail properly later in loadAgent
+    }
+  }
+  return undefined;
+}
+
 export interface BaseAgentDefinition<
   TOutput extends z.ZodTypeAny = z.ZodUnknown,
 > {
@@ -172,11 +229,10 @@ export interface LocalAgentDefinition<
   processOutput?: (output: z.infer<TOutput>) => string;
 }
 
-export interface RemoteAgentDefinition<
+export interface BaseRemoteAgentDefinition<
   TOutput extends z.ZodTypeAny = z.ZodUnknown,
 > extends BaseAgentDefinition<TOutput> {
   kind: 'remote';
-  agentCardUrl: string;
   /** The user-provided description, before any remote card merging. */
   originalDescription?: string;
   /**
@@ -187,6 +243,13 @@ export interface RemoteAgentDefinition<
   auth?: A2AAuthConfig;
 }
 
+export interface RemoteAgentDefinition<
+  TOutput extends z.ZodTypeAny = z.ZodUnknown,
+> extends BaseRemoteAgentDefinition<TOutput> {
+  agentCardUrl?: string;
+  agentCardJson?: string;
+}
+
 export type AgentDefinition<TOutput extends z.ZodTypeAny = z.ZodUnknown> =
   | LocalAgentDefinition<TOutput>
   | RemoteAgentDefinition<TOutput>;

packages/core/src/config/config.ts

@@ -1027,7 +1027,7 @@ export class Config implements McpContext, AgentLoopContext {
     this.model = params.model;
     this.disableLoopDetection = params.disableLoopDetection ?? false;
     this._activeModel = params.model;
-    this.enableAgents = params.enableAgents ?? false;
+    this.enableAgents = params.enableAgents ?? true;
     this.agents = params.agents ?? {};
     this.disableLLMCorrection = params.disableLLMCorrection ?? true;
     this.planEnabled = params.plan ?? true;

packages/core/src/index.ts

@@ -88,7 +88,11 @@ export * from './utils/approvalModeUtils.js';
 export * from './utils/fileDiffUtils.js';
 export * from './utils/retry.js';
 export * from './utils/shell-utils.js';
-export { PolicyDecision, ApprovalMode } from './policy/types.js';
+export {
+  PolicyDecision,
+  ApprovalMode,
+  PRIORITY_YOLO_ALLOW_ALL,
+} from './policy/types.js';
 export * from './utils/tool-utils.js';
 export * from './utils/terminalSerializer.js';
 export * from './utils/systemEncoding.js';

packages/core/src/policy/policies/plan.toml

@@ -110,6 +110,8 @@ priority = 70
 modes = ["plan"]
 
 # Allow write_file and replace for .md files in the plans directory (cross-platform)
+# We split this into two rules to avoid ReDoS checker issues with nested optional segments.
+# This rule handles the case where there is a session ID in the plan file path
 [[rule]]
 toolName = ["write_file", "replace"]
 decision = "allow"
@@ -117,6 +119,14 @@ priority = 70
 modes = ["plan"]
 argsPattern = "\\x00\"file_path\":\"[^\"]+[\\\\/]+\\.gemini[\\\\/]+tmp[\\\\/]+[\\w-]+[\\\\/]+[\\w-]+[\\\\/]+plans[\\\\/]+[\\w-]+\\.md\"\\x00"
 
+# This rule handles the case where there isn't a session ID in the plan file path
+[[rule]]
+toolName = ["write_file", "replace"]
+decision = "allow"
+priority = 70
+modes = ["plan"]
+argsPattern = "\\x00\"file_path\":\"[^\"]+[\\\\/]+\\.gemini[\\\\/]+tmp[\\\\/]+[\\w-]+[\\\\/]+plans[\\\\/]+[\\w-]+\\.md\"\\x00"
+
 # Explicitly Deny other write operations in Plan mode with a clear message.
 [[rule]]
 toolName = ["write_file", "replace"]

packages/core/src/policy/policy-engine.ts

@@ -702,15 +702,6 @@ export class PolicyEngine {
       }
     }
 
-    // Sandbox Expansion requests MUST always be confirmed by the user,
-    // even if the base command is otherwise ALLOWED by the policy engine.
-    if (
-      decision === PolicyDecision.ALLOW &&
-      toolCall.args?.['additional_permissions']
-    ) {
-      decision = PolicyDecision.ASK_USER;
-    }
-
     return {
       decision: this.applyNonInteractiveMode(decision),
       rule: matchedRule,

packages/core/src/tools/definitions/coreTools.ts

@@ -233,13 +233,19 @@ export {
 export function getShellDefinition(
   enableInteractiveShell: boolean,
   enableEfficiency: boolean,
+  enableToolSandboxing: boolean = false,
 ): ToolDefinition {
   return {
-    base: getShellDeclaration(enableInteractiveShell, enableEfficiency),
+    base: getShellDeclaration(
+      enableInteractiveShell,
+      enableEfficiency,
+      enableToolSandboxing,
+    ),
     overrides: (modelId) =>
       getToolSet(modelId).run_shell_command(
         enableInteractiveShell,
         enableEfficiency,
+        enableToolSandboxing,
       ),
   };
 }

packages/core/src/tools/definitions/coreToolsModelSnapshots.test.ts

@@ -69,7 +69,7 @@ describe('coreTools snapshots for specific models', () => {
     { name: 'list_directory', definition: LS_DEFINITION },
     {
       name: 'run_shell_command',
-      definition: getShellDefinition(true, true),
+      definition: getShellDefinition(true, true, true),
     },
     { name: 'replace', definition: EDIT_DEFINITION },
     { name: 'google_web_search', definition: WEB_SEARCH_DEFINITION },

packages/core/src/tools/definitions/dynamic-declaration-helpers.ts

@@ -81,6 +81,7 @@ export function getCommandDescription(): string {
 export function getShellDeclaration(
   enableInteractiveShell: boolean,
   enableEfficiency: boolean,
+  enableToolSandboxing: boolean = false,
 ): FunctionDeclaration {
   return {
     name: SHELL_TOOL_NAME,
@@ -110,35 +111,39 @@ export function getShellDeclaration(
           description:
             'Set to true if this command should be run in the background (e.g. for long-running servers or watchers). The command will be started, allowed to run for a brief moment to check for immediate errors, and then moved to the background.',
         },
-        [PARAM_ADDITIONAL_PERMISSIONS]: {
-          type: 'object',
-          description:
-            'Sandbox permissions for the command. Use this to request additional sandboxed filesystem or network permissions if a previous command failed with "Operation not permitted".',
-          properties: {
-            network: {
-              type: 'boolean',
-              description:
-                'Set to true to enable network access for this command.',
-            },
-            fileSystem: {
-              type: 'object',
-              properties: {
-                read: {
-                  type: 'array',
-                  items: { type: 'string' },
-                  description:
-                    'List of additional absolute paths to allow reading.',
-                },
-                write: {
-                  type: 'array',
-                  items: { type: 'string' },
-                  description:
-                    'List of additional absolute paths to allow writing.',
+        ...(enableToolSandboxing
+          ? {
+              [PARAM_ADDITIONAL_PERMISSIONS]: {
+                type: 'object',
+                description:
+                  'Sandbox permissions for the command. Use this to request additional sandboxed filesystem or network permissions if a previous command failed with "Operation not permitted".',
+                properties: {
+                  network: {
+                    type: 'boolean',
+                    description:
+                      'Set to true to enable network access for this command.',
+                  },
+                  fileSystem: {
+                    type: 'object',
+                    properties: {
+                      read: {
+                        type: 'array',
+                        items: { type: 'string' },
+                        description:
+                          'List of additional absolute paths to allow reading.',
+                      },
+                      write: {
+                        type: 'array',
+                        items: { type: 'string' },
+                        description:
+                          'List of additional absolute paths to allow writing.',
+                      },
+                    },
+                  },
                 },
               },
-            },
-          },
-        },
+            }
+          : {}),
       },
       required: [SHELL_PARAM_COMMAND],
     },

packages/core/src/tools/definitions/model-family-sets/default-legacy.ts

@@ -332,8 +332,16 @@ export const DEFAULT_LEGACY_SET: CoreToolSet = {
     },
   },
 
-  run_shell_command: (enableInteractiveShell, enableEfficiency) =>
-    getShellDeclaration(enableInteractiveShell, enableEfficiency),
+  run_shell_command: (
+    enableInteractiveShell,
+    enableEfficiency,
+    enableToolSandboxing,
+  ) =>
+    getShellDeclaration(
+      enableInteractiveShell,
+      enableEfficiency,
+      enableToolSandboxing,
+    ),
 
   replace: {
     name: EDIT_TOOL_NAME,

packages/core/src/tools/definitions/model-family-sets/gemini-3.ts

@@ -338,8 +338,16 @@ export const GEMINI_3_SET: CoreToolSet = {
     },
   },
 
-  run_shell_command: (enableInteractiveShell, enableEfficiency) =>
-    getShellDeclaration(enableInteractiveShell, enableEfficiency),
+  run_shell_command: (
+    enableInteractiveShell,
+    enableEfficiency,
+    enableToolSandboxing,
+  ) =>
+    getShellDeclaration(
+      enableInteractiveShell,
+      enableEfficiency,
+      enableToolSandboxing,
+    ),
 
   replace: {
     name: EDIT_TOOL_NAME,

packages/core/src/tools/definitions/types.ts

@@ -37,6 +37,7 @@ export interface CoreToolSet {
   run_shell_command: (
     enableInteractiveShell: boolean,
     enableEfficiency: boolean,
+    enableToolSandboxing: boolean,
   ) => FunctionDeclaration;
   replace: FunctionDeclaration;
   google_web_search: FunctionDeclaration;

packages/core/src/tools/shell.test.ts

@@ -137,6 +137,7 @@ describe('ShellTool', () => {
       getShellToolInactivityTimeout: vi.fn().mockReturnValue(1000),
       getEnableInteractiveShell: vi.fn().mockReturnValue(false),
       getEnableShellOutputEfficiency: vi.fn().mockReturnValue(true),
+      getSandboxEnabled: vi.fn().mockReturnValue(false),
       sanitizationConfig: {},
       sandboxManager: new NoopSandboxManager(),
     } as unknown as Config;

packages/core/src/tools/shell.ts

@@ -696,6 +696,7 @@ export class ShellTool extends BaseDeclarativeTool<
     const definition = getShellDefinition(
       context.config.getEnableInteractiveShell(),
       context.config.getEnableShellOutputEfficiency(),
+      context.config.getSandboxEnabled(),
     );
     super(
       ShellTool.Name,
@@ -745,6 +746,7 @@ export class ShellTool extends BaseDeclarativeTool<
     const definition = getShellDefinition(
       this.context.config.getEnableInteractiveShell(),
       this.context.config.getEnableShellOutputEfficiency(),
+      this.context.config.getSandboxEnabled(),
     );
     return resolveToolDeclaration(definition, modelId);
   }

packages/devtools/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-devtools",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "license": "Apache-2.0",
   "type": "module",
   "main": "dist/src/index.js",

packages/sdk/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-sdk",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "description": "Gemini CLI SDK",
   "license": "Apache-2.0",
   "repository": {

packages/test-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-test-utils",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "private": true,
   "main": "src/index.ts",
   "license": "Apache-2.0",

packages/vscode-ide-companion/package.json

@@ -2,7 +2,7 @@
   "name": "gemini-cli-vscode-ide-companion",
   "displayName": "Gemini CLI Companion",
   "description": "Enable Gemini CLI with direct access to your IDE workspace.",
-  "version": "0.36.0-nightly.20260317.2f90b4653",
+  "version": "0.36.0-preview.3",
   "publisher": "google",
   "icon": "assets/icon.png",
   "repository": {

schemas/settings.schema.json

@@ -2680,8 +2680,8 @@
         "enableAgents": {
           "title": "Enable Agents",
           "description": "Enable local and remote subagents.",
-          "markdownDescription": "Enable local and remote subagents.\n\n- Category: `Experimental`\n- Requires restart: `yes`\n- Default: `false`",
-          "default": false,
+          "markdownDescription": "Enable local and remote subagents.\n\n- Category: `Experimental`\n- Requires restart: `yes`\n- Default: `true`",
+          "default": true,
           "type": "boolean"
         },
         "worktrees": {