chore: import upstream snapshot with attribution

packages/a2a-server/GEMINI.md

@@ -0,0 +1,22 @@
+# Gemini CLI A2A Server (`@google/gemini-cli-a2a-server`)
+
+Experimental Agent-to-Agent (A2A) server that exposes Gemini CLI capabilities
+over HTTP for inter-agent communication.
+
+## Architecture
+
+- `src/agent/`: Agent session management for A2A interactions.
+- `src/commands/`: CLI command definitions for the A2A server binary.
+- `src/config/`: Server configuration.
+- `src/http/`: HTTP server and route handlers.
+- `src/persistence/`: Session and state persistence.
+- `src/utils/`: Shared utility functions.
+- `src/types.ts`: Shared type definitions.
+
+## Running
+
+- Binary entry point: `gemini-cli-a2a-server`
+
+## Testing
+
+- Run tests: `npm test -w @google/gemini-cli-a2a-server`

packages/a2a-server/README.md

@@ -0,0 +1,5 @@
+# Gemini CLI A2A Server
+
+## All code in this package is experimental and under active development
+
+This package contains the A2A server implementation for the Gemini CLI.

packages/a2a-server/development-extension-rfc.md

@@ -0,0 +1,509 @@
+# RFC: Gemini CLI A2A Development-Tool Extension
+
+## 1. Introduction
+
+### 1.1 Overview
+
+To standardize client integrations with the Gemini CLI agent, this document
+proposes the `development-tool` extension for the A2A protocol.
+
+Rather than creating a new protocol, this specification builds upon the existing
+A2A protocol. As an open-source standard recently adopted by the Linux
+Foundation, A2A provides a robust foundation for core concepts like tasks,
+messages, and streaming events. This extension-based approach allows us to
+leverage A2A's proven architecture while defining the specific capabilities
+required for rich, interactive workflows with the Gemini CLI agent.
+
+### 1.2 Motivation
+
+Recent work integrating Gemini CLI with clients like Zed and Gemini Code
+Assist’s agent mode has highlighted the need for a robust, standard
+communication protocol. Standardizing on A2A provides several key advantages:
+
+- **Solid Foundation**: Provides a robust, open standard that ensures a stable,
+  predictable, and consistent integration experience across different IDEs and
+  client surfaces.
+- **Extensibility**: Creates a flexible foundation to support new tools and
+  workflows as they emerge.
+- **Ecosystem Alignment**: Aligns Gemini CLI with a growing industry standard,
+  fostering broader interoperability.
+
+## 2. Communication Flow
+
+The interaction follows A2A’s task-based, streaming pattern. The client sends a
+`message/stream` request and the agent responds with a `contextId` / `taskId`
+and a stream of events. `TaskStatusUpdateEvent` events are used to convey the
+overall state of the task. The task is complete when the agent sends a final
+`TaskStatusUpdateEvent` with `final: true` and a terminal status like
+`completed` or `failed`.
+
+### 2.1 Asynchronous Responses and Notifications
+
+Clients that may disconnect from the agent should supply a
+`PushNotificationConfig` to the agent with the initial `message/stream` method
+or subsequently with the `tasks/pushNotificationConfig/set` method so that the
+agent can call back when updates are ready.
+
+## 3. The `development-tool` extension
+
+### 3.1 Overview
+
+The `development-tool` extension establishes a communication contract for
+workflows between a client and the Gemini CLI agent. It consists of a
+specialized set of schemas, embedded within core A2A data structures, that
+enable the agent to stream real-time updates on its state and thought process.
+These schemas also provide the mechanism for the agent to request user
+permission before executing tools.
+
+**Sample Agent Card**
+
+```json
+{
+  "name": "Gemini CLI Agent",
+  "description": "An agent that generates code based on natural language instructions.",
+  "capabilities": {
+    "streaming": true,
+    "extensions": [
+      {
+        "uri": "https://github.com/google-gemini/gemini-cli/blob/main/docs/a2a/developer-profile/v0/spec.md",
+        "description": "An extension for interactive development tasks, enabling features like code generation, tool usage, and real-time status updates.",
+        "required": true
+      }
+    ]
+  }
+}
+```
+
+**Versioning**
+
+The agent card `uri` field contains an embedded semantic version. The client
+must extract this version to determine compatibility with the agent extension
+using the compatibility logic defined in Semantic Versioning 2.0.0 spec.
+
+### 3.2 Schema Definitions
+
+This section defines the schemas for the `development-tool` A2A extension,
+organized by their function within the communication flow. Note that all custom
+objects included in the `metadata` field (e.g. `Message.metadata`) must be keyed
+by the unique URI that points to that extension’s spec to prevent naming
+collisions with other extensions.
+
+**Initialization & Configuration**
+
+The first message in a session must contain an `AgentSettings` object in its
+metadata. This object provides the agent with the necessary configuration
+information for proper initialization. Additional configuration settings (ex.
+MCP servers, allowed tools, etc.) can be added to this message.
+
+**Schema**
+
+```proto
+syntax = "proto3";
+
+// Configuration settings for the Gemini CLI agent.
+message AgentSettings {
+  // The absolute path to the workspace directory where the agent will execute.
+  string workspace_path = 1;
+}
+```
+
+**Agent-to-Client Messages**
+
+All real-time updates from the agent (including its thoughts, tool calls, and
+simple text replies) are streamed to the client as `TaskStatusUpdateEvents`.
+
+Each Event contains a `Message` object, which holds the content in one of two
+formats:
+
+- **TextPart**: Used for standard text messages. This part requires no custom
+  schema.
+- **DataPart**: Used for complex, structured objects. Tool Calls and Thoughts
+  are sent this way, each using their respective schemas defined below.
+
+**Tool Calls**
+
+The `ToolCall` schema is designed to provide a structured representation of a
+tool’s execution lifecycle. This protocol defines a clear state machine and
+provides detailed schemas for common development tasks (file edits, shell
+commands, MCP Tool), ensuring clients can build reliable UIs without being tied
+to a specific agent implementation.
+
+The core principle is that the agent sends a `ToolCall` object on every update.
+This makes client-side logic stateless and simple.
+
+**Tool Call Lifecycle**
+
+1.  **Creation**: The agent sends a `ToolCall` object with `status: PENDING`. If
+    user permission is required, the `confirmation_request` field will be
+    populated.
+2.  **Confirmation**: If the client needs to confirm the message, the client
+    will send a `ToolCallConfirmation`. If the client responds with a
+    cancellation, execution will be skipped.
+3.  **Execution**: Once approved (or if no approval is required), the agent
+    sends an update with `status: EXECUTING`. It can stream real-time progress
+    by updating the `live_content` field.
+4.  **Completion**: The agent sends a final update with the status set to
+    `SUCCEEDED`, `FAILED`, or `CANCELLED` and populates the appropriate result
+    field.
+
+**Schema**
+
+```proto
+syntax = "proto3";
+
+import "google/protobuf/struct.proto";
+
+// ToolCall is the central message representing a tool's execution lifecycle.
+// The entire object is sent from the agent to client on every update.
+message ToolCall {
+  // A unique identifier, assigned by the agent
+  string tool_call_id = 1;
+
+  // The current state of the tool call in its lifecycle
+  ToolCallStatus status = 2;
+
+  // Name of the tool being called (e.g. 'Edit', 'ShellTool')
+  string tool_name = 3;
+
+  // An optional description of the tool call's purpose to show the user
+  optional string description = 4;
+
+  // The structured input params provided by the LLM for tool invocation.
+  google.protobuf.Struct input_parameters = 5;
+
+  // String containing the real-time output from the tool as it executes (primarily designed for shell output).
+  // During streaming the entire string is replaced on each update
+  optional string live_content = 6;
+
+  // The final result of the tool (used to replace live_content when applicable)
+  oneof result {
+    // The output on tool success
+    ToolOutput output = 7;
+    // The error details if the tool failed
+    ErrorDetails error = 8;
+  }
+
+  // If the tool requires user confirmation, this field will be populated while status is PENDING
+  optional ConfirmationRequest confirmation_request = 9;
+}
+
+// Possible execution status of a ToolCall
+enum ToolCallStatus {
+  STATUS_UNSPECIFIED = 0;
+  PENDING = 1;
+  EXECUTING = 2;
+  SUCCEEDED = 3;
+  FAILED = 4;
+  CANCELLED = 5;
+}
+
+// ToolOutput represents the final, successful, output of a tool
+message ToolOutput {
+  oneof result {
+    string text = 1;
+    // For ToolCalls which resulted in a file modification
+    FileDiff diff = 2;
+    // A generic fallback for any other structured JSON data
+    google.protobuf.Struct structured_data = 3;
+  }
+}
+
+// A structured representation of an error
+message ErrorDetails {
+  // User facing error message
+  string message = 1;
+  // Optional agent-specific error type or category (e.g. read_content_failure, grep_execution_error, mcp_tool_error)
+  optional string type = 2;
+  // Optional status code
+  optional int32 status_code = 3;
+}
+
+// ConfirmationRequest is sent from the agent to client to request user permission for a ToolCall
+message ConfirmationRequest {
+  // A list of choices for the user to select from
+  repeated ConfirmationOption options = 1;
+  // Specific details of the action requiring user confirmation
+  oneof details {
+    ExecuteDetails execute_details = 2;
+    FileDiff file_edit_details = 3;
+    McpDetails mcp_details = 4;
+    GenericDetails generic_details = 5;
+  }
+}
+
+// A single choice presented to the user during a confirmation request
+message ConfirmationOption {
+  // Unique ID for the choice (e.g. proceed_once, cancel)
+  string id = 1;
+  // Human-readable choice (e.g. Allow Once, Reject).
+  string name = 2;
+  // An optional longer description for a tooltip
+  optional string description = 3;
+}
+
+// Details for a request to execute a shell command
+message ExecuteDetails {
+  // The shell command to be executed
+  string command = 1;
+  // An optional directory in which the command will be run
+  optional string working_directory = 2;
+}
+
+
+message FileDiff {
+  string file_name = 1;
+  // The absolute path to the file to modify
+  string file_path = 2;
+  // The original content, if the file exists
+  optional string old_content = 3;
+  string new_content = 4;
+  // Pre-formatted diff string for display
+  optional string formatted_diff = 5;
+}
+
+// Details for an MCP (Model Context Protocol) tool confirmation
+message McpDetails {
+  // The name of the MCP server that provides the tool
+  string server_name = 1;
+  // THe name of the tool being called from the MCP Server
+  string tool_name = 2;
+}
+
+// Generic catch-all for ToolCall requests that don't fit other types
+message GenericDetails {
+  // Description of the action requiring confirmation
+  string description = 1;
+}
+```
+
+**Agent Thoughts**
+
+**Schema**
+
+```proto
+syntax = "proto3";
+
+// Represents a thought with a subject and a detailed description.
+message AgentThought {
+  // A concise subject line or title for the thought.
+  string subject = 1;
+
+  // The description or elaboration of the thought itself.
+  string description = 2;
+}
+```
+
+**Event Metadata**
+
+The `metadata` object in `TaskStatusUpdateEvent` is used by the A2A client to
+deserialize the `TaskStatusUpdateEvents` into their appropriate objects.
+
+**Schema**
+
+```proto
+syntax = "proto3";
+
+// A DevelopmentToolEvent event.
+message DevelopmentToolEvent {
+  // Enum representing the specific type of development tool event.
+  enum DevelopmentToolEventKind {
+    // The default, unspecified value.
+    DEVELOPMENT_TOOL_EVENT_KIND_UNSPECIFIED = 0;
+    TOOL_CALL_CONFIRMATION = 1;
+    TOOL_CALL_UPDATE = 2;
+    TEXT_CONTENT = 3;
+    STATE_CHANGE = 4;
+    THOUGHT = 5;
+  }
+
+  // The specific kind of event that occurred.
+  DevelopmentToolEventKind kind = 1;
+
+  // The model used for this event.
+  string model = 2;
+
+  // The tier of the user (optional).
+  string user_tier = 3;
+
+  // An unexpected error occurred in the agent execution (optional).
+  string error = 4;
+}
+```
+
+**Client-to-Agent Messages**
+
+When the agent sends a `TaskStatusUpdateEvent` with `status.state` set to
+`input-required` and its message contains a `ConfirmationRequest`, the client
+must respond by sending a new `message/stream` request.
+
+This new request must include the `contextId` and the `taskId` from the ongoing
+task and contain a `ToolCallConfirmation` object. This object conveys the user's
+decision regarding the tool call that was awaiting approval.
+
+**Schema**
+
+```proto
+syntax = "proto3";
+
+// The client's response to a ConfirmationRequest.
+message ToolCallConfirmation {
+  // A unique identifier, assigned by the agent
+  string tool_call_id = 1;
+  // The 'id' of the ConfirmationOption chosen by the user.
+  string selected_option_id = 2;
+  // Included if the user modifies the proposed change.
+  // The type should correspond to the original ConfirmationRequest details.
+  oneof modified_details {
+    // Corresponds to a FileDiff confirmation
+    ModifiedFileDetails file_details = 3;
+  }
+}
+
+message ModifiedFileDetails {
+  // The new content after user edits.
+  string new_content = 1;
+}
+```
+
+### 3.3 Method Definitions
+
+This section defines the new methods introduced by the `development-tool`
+extension.
+
+**Method: `commands/get`**
+
+This method allows the client to discover slash commands supported by Gemini
+CLI. The client should call this method during startup to dynamically populate
+its command list.
+
+```proto
+// Response message containing the list of all top-level slash commands.
+message GetAllSlashCommandsResponse {
+  // A list of the top-level slash commands.
+  repeated SlashCommand commands = 1;
+}
+
+// Represents a single slash command, which can contain subcommands.
+message SlashCommand {
+  // The primary name of the command.
+  string name = 1;
+  // A detailed description of what the command does.
+  string description = 2;
+  // A list of arguments that the command accepts.
+  repeated SlashCommandArgument arguments = 3;
+  // A list of nested subcommands.
+  repeated SlashCommand sub_commands = 4;
+}
+
+// Defines the structure for a single slash command argument.
+message SlashCommandArgument {
+  // The name of the argument.
+  string name = 1;
+  // A brief description of what the argument is for.
+  string description = 2;
+  // Whether the argument is required or optional.
+  bool is_required = 3;
+}
+```
+
+**Method: `command/execute`**
+
+This method allows the client to execute a slash command. Following the initial
+`ExecuteSlashCommandResponse`, the agent will use the standard streaming
+mechanism to communicate the command's progress and output. All subsequent
+updates, including textual output, agent thoughts, and any required user
+confirmations for tool calls (like executing a shell command), will be sent as
+`TaskStatusUpdateEvent` messages, re-using the schemas defined above.
+
+```proto
+// Request to execute a specific slash command.
+message ExecuteSlashCommandRequest {
+  // The path to the command, e.g., ["memory", "list"] for /memory list
+  repeated string command_path = 1;
+  // The arguments for the command as a single string.
+  string args = 2;
+}
+
+// Enum for the initial status of a command execution request.
+enum CommandExecutionStatus {
+  // Default unspecified status.
+  COMMAND_EXECUTION_STATUS_UNSPECIFIED = 0;
+  // The command was successfully received and its execution has started.
+  STARTED = 1;
+  // The command failed to start (e.g., command not found, invalid format).
+  FAILED_TO_START = 2;
+  // The command has been paused and is waiting for the user to confirm
+  // a set of shell commands.
+  AWAITING_SHELL_CONFIRMATION = 3;
+  // The command has been paused and is waiting for the user to confirm
+  // a specific action.
+  AWAITING_ACTION_CONFIRMATION = 4;
+}
+
+// The immediate, async response after requesting a command execution.
+message ExecuteSlashCommandResponse {
+  // A unique taskID for this specific command execution.
+  string execution_id = 1;
+  // The initial status of the command execution.
+  CommandExecutionStatus status = 2;
+  // An optional message, particularly useful for explaining why a command
+  // failed to start.
+  string message = 3;
+}
+```
+
+## 4. Separation of Concerns
+
+We believe that all client-side context (ex., workspace state) and client-side
+tool execution (ex. read active buffers) should be routed through MCP.
+
+This approach enforces a strict separation of concerns: the A2A
+`development-tool` extension standardizes communication to the agent, while MCP
+serves as the single, authoritative interface for client-side capabilities.
+
+## Appendix
+
+### A. Example Interaction Flow
+
+1.  **Client -> Server**: The client sends a `message/stream` request containing
+    the initial prompt and configuration in an `AgentSettings` object.
+2.  **Server -> Client**: SSE stream begins.
+    - **Event 1**: The server sends a `Task` object with
+      `status.state: 'submitted'` and the new `taskId`.
+    - **Event 2**: The server sends a `TaskStatusUpdateEvent` with the metadata
+      `kind` set to `'STATE_CHANGE'` and `status.state` set to `'working'`.
+3.  **Agent Logic**: The agent processes the prompt and decides to call the
+    `write_file` tool, which requires user confirmation.
+4.  **Server -> Client**:
+    - **Event 3**: The server sends a `TaskStatusUpdateEvent`. The metadata
+      `kind` is `'TOOL_CALL_UPDATE'`, and the `DataPart` contains a `ToolCall`
+      object with its `status` as `'PENDING'` and a populated
+      `confirmation_request`.
+    - **Event 4**: The server sends a final `TaskStatusUpdateEvent` for this
+      exchange. The metadata `kind` is `'STATE_CHANGE'`, the `status.state` is
+      `'input-required'`, and `final` is `true`. The stream for this request
+      ends.
+5.  **Client**: The client UI renders the confirmation prompt based on the
+    `ToolCall` object from Event 3. The user clicks "Approve."
+6.  **Client -> Server**: The client sends a new `message/stream` request. It
+    includes the `taskId` from the ongoing task and a `DataPart` containing a
+    `ToolCallConfirmation` object (e.g.,
+    `{"tool_call_id": "...", "selected_option_id": "proceed_once"}`).
+7.  **Server -> Client**: A new SSE stream begins for the second request.
+    - **Event 1**: The server sends a `TaskStatusUpdateEvent` with
+      `kind: 'TOOL_CALL_UPDATE'`, containing the `ToolCall` object with its
+      `status` now set to `'EXECUTING'`.
+    - **Event 2**: After the tool runs, the server sends another
+      `TaskStatusUpdateEvent` with `kind: 'TOOL_CALL_UPDATE'`, containing the
+      `ToolCall` with its `status` as `'SUCCEEDED'`.
+8.  **Agent Logic**: The agent receives the successful tool result and generates
+    a final textual response.
+9.  **Server -> Client**:
+    - **Event 3**: The server sends a `TaskStatusUpdateEvent` with
+      `kind: 'TEXT_CONTENT'` and a `TextPart` containing the agent's final
+      answer.
+    - **Event 4**: The server sends the final `TaskStatusUpdateEvent`. The
+      `kind` is `'STATE_CHANGE'`, the `status.state` is `'completed'`, and
+      `final` is `true`. The stream ends.
+10. **Client**: The client displays the final answer. The task is now complete
+    but can be continued by sending another message with the same `taskId`.

packages/a2a-server/index.ts

@@ -0,0 +1,7 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export * from './src/index.js';

packages/a2a-server/package.json

@@ -0,0 +1,52 @@
+{
+  "name": "@google/gemini-cli-a2a-server",
+  "version": "0.52.0-nightly.20260707.g27a3da3e8",
+  "description": "Gemini CLI A2A Server",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/google-gemini/gemini-cli.git",
+    "directory": "packages/a2a-server"
+  },
+  "type": "module",
+  "main": "dist/index.js",
+  "bin": {
+    "gemini-cli-a2a-server": "dist/a2a-server.mjs"
+  },
+  "scripts": {
+    "build": "node ../../scripts/build_package.js",
+    "start": "node dist/src/http/server.js",
+    "lint": "eslint . --ext .ts,.tsx",
+    "format": "prettier --write .",
+    "test": "vitest run",
+    "test:ci": "vitest run --coverage",
+    "typecheck": "tsc --noEmit"
+  },
+  "files": [
+    "dist"
+  ],
+  "dependencies": {
+    "@a2a-js/sdk": "0.3.11",
+    "@google-cloud/storage": "7.19.0",
+    "@google/gemini-cli-core": "file:../core",
+    "express": "5.1.0",
+    "fs-extra": "11.3.0",
+    "strip-json-comments": "3.1.1",
+    "tar": "7.5.8",
+    "uuid": "13.0.0",
+    "winston": "3.17.0"
+  },
+  "devDependencies": {
+    "@google/genai": "1.30.0",
+    "@types/express": "5.0.3",
+    "@types/fs-extra": "11.0.4",
+    "@types/supertest": "6.0.3",
+    "@types/tar": "6.1.13",
+    "dotenv": "16.4.5",
+    "supertest": "7.1.4",
+    "typescript": "5.8.3",
+    "vitest": "3.2.4"
+  },
+  "engines": {
+    "node": ">=20"
+  }
+}

packages/a2a-server/src/agent/executor.test.ts

@@ -0,0 +1,303 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, type Mock } from 'vitest';
+import { CoderAgentExecutor } from './executor.js';
+import type {
+  ExecutionEventBus,
+  RequestContext,
+  TaskStore,
+} from '@a2a-js/sdk/server';
+import { EventEmitter } from 'node:events';
+import { requestStorage } from '../http/requestStorage.js';
+
+// Mocks for constructor dependencies
+vi.mock('../config/config.js', () => ({
+  loadConfig: vi.fn().mockReturnValue({
+    getSessionId: () => 'test-session',
+    getTargetDir: () => '/tmp',
+    getCheckpointingEnabled: () => false,
+  }),
+  loadEnvironment: vi.fn(),
+  setIsTrusted: vi.fn().mockReturnValue(false),
+  setTargetDir: vi.fn().mockReturnValue('/tmp'),
+}));
+
+vi.mock('../config/settings.js', () => ({
+  loadSettings: vi.fn().mockReturnValue({}),
+}));
+
+vi.mock('../config/extension.js', () => ({
+  loadExtensions: vi.fn().mockReturnValue([]),
+}));
+
+vi.mock('../http/requestStorage.js', () => ({
+  requestStorage: {
+    getStore: vi.fn(),
+  },
+}));
+
+vi.mock('./task.js', () => {
+  const mockTaskInstance = (taskId: string, contextId: string) => ({
+    id: taskId,
+    contextId,
+    taskState: 'working',
+    acceptUserMessage: vi
+      .fn()
+      .mockImplementation(async function* (context, aborted) {
+        const isConfirmation = (
+          context.userMessage.parts as Array<{ kind: string }>
+        ).some((p) => p.kind === 'confirmation');
+        // Hang only for main user messages (text), allow confirmations to finish quickly
+        if (!isConfirmation && aborted) {
+          await new Promise((resolve) => {
+            aborted.addEventListener('abort', resolve, { once: true });
+          });
+        }
+        yield { type: 'content', value: 'hello' };
+      }),
+    acceptAgentMessage: vi.fn().mockResolvedValue(undefined),
+    scheduleToolCalls: vi.fn().mockResolvedValue(undefined),
+    waitForPendingTools: vi.fn().mockResolvedValue(undefined),
+    getAndClearCompletedTools: vi.fn().mockReturnValue([]),
+    get hasPendingTools() {
+      return false;
+    },
+    get pendingToolsCount() {
+      return 0;
+    },
+    addToolResponsesToHistory: vi.fn(),
+    sendCompletedToolsToLlm: vi.fn().mockImplementation(async function* () {}),
+    cancelPendingTools: vi.fn(),
+    setTaskStateAndPublishUpdate: vi.fn(),
+    dispose: vi.fn(),
+    getMetadata: vi.fn().mockResolvedValue({}),
+    geminiClient: {
+      initialize: vi.fn().mockResolvedValue(undefined),
+    },
+    toSDKTask: () => ({
+      id: taskId,
+      contextId,
+      kind: 'task',
+      status: { state: 'working', timestamp: new Date().toISOString() },
+      metadata: {},
+      history: [],
+      artifacts: [],
+    }),
+  });
+
+  const MockTask = vi.fn().mockImplementation(mockTaskInstance);
+  (MockTask as unknown as { create: Mock }).create = vi
+    .fn()
+    .mockImplementation(async (taskId: string, contextId: string) =>
+      mockTaskInstance(taskId, contextId),
+    );
+
+  return { Task: MockTask };
+});
+
+describe('CoderAgentExecutor', () => {
+  let executor: CoderAgentExecutor;
+  let mockTaskStore: TaskStore;
+  let mockEventBus: ExecutionEventBus;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockTaskStore = {
+      save: vi.fn().mockResolvedValue(undefined),
+      load: vi.fn().mockResolvedValue(undefined),
+      delete: vi.fn().mockResolvedValue(undefined),
+      list: vi.fn().mockResolvedValue([]),
+    } as unknown as TaskStore;
+
+    mockEventBus = new EventEmitter() as unknown as ExecutionEventBus;
+    mockEventBus.publish = vi.fn();
+    mockEventBus.finished = vi.fn();
+
+    executor = new CoderAgentExecutor(mockTaskStore);
+  });
+
+  it('should distinguish between primary and secondary execution', async () => {
+    const taskId = 'test-task';
+    const contextId = 'test-context';
+
+    const mockSocket = new EventEmitter();
+    const requestContext = {
+      userMessage: {
+        messageId: 'msg-1',
+        taskId,
+        contextId,
+        parts: [{ kind: 'text', text: 'hi' }],
+        metadata: {
+          coderAgent: { kind: 'agent-settings', workspacePath: '/tmp' },
+        },
+      },
+    } as unknown as RequestContext;
+
+    // Mock requestStorage for primary
+    (requestStorage.getStore as Mock).mockReturnValue({
+      req: { socket: mockSocket },
+    });
+
+    // First execution (Primary)
+    const primaryPromise = executor.execute(requestContext, mockEventBus);
+
+    // Give it enough time to reach line 490 in executor.ts
+    await new Promise((resolve) => setTimeout(resolve, 50));
+
+    expect(
+      (
+        executor as unknown as { executingTasks: Set<string> }
+      ).executingTasks.has(taskId),
+    ).toBe(true);
+    const wrapper = executor.getTask(taskId);
+    expect(wrapper).toBeDefined();
+
+    // Mock requestStorage for secondary
+    const secondarySocket = new EventEmitter();
+    (requestStorage.getStore as Mock).mockReturnValue({
+      req: { socket: secondarySocket },
+    });
+
+    const secondaryRequestContext = {
+      userMessage: {
+        messageId: 'msg-2',
+        taskId,
+        contextId,
+        parts: [{ kind: 'confirmation', callId: '1', outcome: 'proceed' }],
+        metadata: {
+          coderAgent: { kind: 'agent-settings', workspacePath: '/tmp' },
+        },
+      },
+    } as unknown as RequestContext;
+
+    const secondaryPromise = executor.execute(
+      secondaryRequestContext,
+      mockEventBus,
+    );
+
+    // Secondary execution should NOT add to executingTasks (already there)
+    // and should return early after its loop
+    await secondaryPromise;
+
+    // Task should still be in executingTasks and NOT disposed
+    expect(
+      (
+        executor as unknown as { executingTasks: Set<string> }
+      ).executingTasks.has(taskId),
+    ).toBe(true);
+    expect(wrapper?.task.dispose).not.toHaveBeenCalled();
+
+    // Now simulate secondary socket closure - it should NOT affect primary
+    secondarySocket.emit('end');
+    expect(
+      (
+        executor as unknown as { executingTasks: Set<string> }
+      ).executingTasks.has(taskId),
+    ).toBe(true);
+    expect(wrapper?.task.dispose).not.toHaveBeenCalled();
+
+    // Set to terminal state to verify disposal on finish
+    wrapper!.task.taskState = 'completed';
+
+    // Now close primary socket
+    mockSocket.emit('end');
+
+    await primaryPromise;
+
+    expect(
+      (
+        executor as unknown as { executingTasks: Set<string> }
+      ).executingTasks.has(taskId),
+    ).toBe(false);
+    expect(wrapper?.task.dispose).toHaveBeenCalled();
+  });
+
+  it('should evict task from cache when it reaches terminal state', async () => {
+    const taskId = 'test-task-terminal';
+    const contextId = 'test-context';
+
+    const mockSocket = new EventEmitter();
+    (requestStorage.getStore as Mock).mockReturnValue({
+      req: { socket: mockSocket },
+    });
+
+    const requestContext = {
+      userMessage: {
+        messageId: 'msg-1',
+        taskId,
+        contextId,
+        parts: [{ kind: 'text', text: 'hi' }],
+        metadata: {
+          coderAgent: { kind: 'agent-settings', workspacePath: '/tmp' },
+        },
+      },
+    } as unknown as RequestContext;
+
+    const primaryPromise = executor.execute(requestContext, mockEventBus);
+    await new Promise((resolve) => setTimeout(resolve, 50));
+
+    const wrapper = executor.getTask(taskId)!;
+    expect(wrapper).toBeDefined();
+    // Simulate terminal state
+    wrapper.task.taskState = 'completed';
+
+    // Finish primary execution
+    mockSocket.emit('end');
+    await primaryPromise;
+
+    expect(executor.getTask(taskId)).toBeUndefined();
+    expect(wrapper.task.dispose).toHaveBeenCalled();
+  });
+
+  it('should yield the turn and transition to input-required if tools are pending', async () => {
+    const taskId = 'test-task-pending-tools';
+    const contextId = 'test-context';
+
+    const mockSocket = new EventEmitter();
+    (requestStorage.getStore as Mock).mockReturnValue({
+      req: { socket: mockSocket },
+    });
+
+    // Pre-create the task to safely modify its mocked methods before execution
+    const wrapper = await executor.createTask(
+      taskId,
+      contextId,
+      undefined,
+      mockEventBus,
+    );
+    const hasPendingToolsSpy = vi
+      .spyOn(wrapper.task, 'hasPendingTools', 'get')
+      .mockReturnValue(true);
+    vi.spyOn(wrapper.task, 'pendingToolsCount', 'get').mockReturnValue(1);
+
+    const requestContext = {
+      userMessage: {
+        messageId: 'msg-1',
+        taskId,
+        contextId,
+        parts: [{ kind: 'confirmation', callId: '1', outcome: 'proceed' }],
+        metadata: {
+          coderAgent: { kind: 'agent-settings', workspacePath: '/tmp' },
+        },
+      },
+    } as unknown as RequestContext;
+
+    await executor.execute(requestContext, mockEventBus);
+
+    // Assert that the executor yielded the turn correctly without further progression
+    expect(hasPendingToolsSpy).toHaveBeenCalled();
+    expect(wrapper.task.getAndClearCompletedTools).not.toHaveBeenCalled();
+    expect(wrapper.task.sendCompletedToolsToLlm).not.toHaveBeenCalled();
+    expect(wrapper.task.setTaskStateAndPublishUpdate).toHaveBeenCalledWith(
+      'input-required',
+      expect.any(Object),
+      undefined,
+      undefined,
+      true,
+    );
+  });
+});

packages/a2a-server/src/agent/executor.ts

@@ -0,0 +1,673 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { Message, Task as SDKTask } from '@a2a-js/sdk';
+import type {
+  TaskStore,
+  AgentExecutor,
+  AgentExecutionEvent,
+  RequestContext,
+  ExecutionEventBus,
+} from '@a2a-js/sdk/server';
+import {
+  GeminiEventType,
+  SimpleExtensionLoader,
+  type ToolCallRequestInfo,
+  type Config,
+} from '@google/gemini-cli-core';
+import { v4 as uuidv4 } from 'uuid';
+
+import { logger } from '../utils/logger.js';
+import {
+  CoderAgentEvent,
+  getPersistedState,
+  setPersistedState,
+  type StateChange,
+  type AgentSettings,
+  type PersistedStateMetadata,
+  getContextIdFromMetadata,
+  getAgentSettingsFromMetadata,
+} from '../types.js';
+import {
+  loadConfig,
+  loadEnvironment,
+  setIsTrusted,
+  setTargetDir,
+} from '../config/config.js';
+import { loadSettings } from '../config/settings.js';
+import { loadExtensions } from '../config/extension.js';
+import { Task } from './task.js';
+import { requestStorage } from '../http/requestStorage.js';
+import { pushTaskStateFailed } from '../utils/executor_utils.js';
+
+/**
+ * Provides a wrapper for Task. Passes data from Task to SDKTask.
+ * The idea is to use this class inside CoderAgentExecutor to replace Task.
+ */
+class TaskWrapper {
+  task: Task;
+  agentSettings: AgentSettings;
+
+  constructor(task: Task, agentSettings: AgentSettings) {
+    this.task = task;
+    this.agentSettings = agentSettings;
+  }
+
+  get id() {
+    return this.task.id;
+  }
+
+  toSDKTask(): SDKTask {
+    const persistedState: PersistedStateMetadata = {
+      _agentSettings: this.agentSettings,
+      _taskState: this.task.taskState,
+    };
+
+    const sdkTask: SDKTask = {
+      id: this.task.id,
+      contextId: this.task.contextId,
+      kind: 'task',
+      status: {
+        state: this.task.taskState,
+        timestamp: new Date().toISOString(),
+      },
+      metadata: setPersistedState({}, persistedState),
+      history: [],
+      artifacts: [],
+    };
+    sdkTask.metadata!['_contextId'] = this.task.contextId;
+    return sdkTask;
+  }
+}
+
+/**
+ * CoderAgentExecutor implements the agent's core logic for code generation.
+ */
+export class CoderAgentExecutor implements AgentExecutor {
+  private tasks: Map<string, TaskWrapper> = new Map();
+  // Track tasks with an active execution loop.
+  private executingTasks = new Set<string>();
+
+  constructor(private taskStore?: TaskStore) {}
+
+  private async getConfig(
+    agentSettings: AgentSettings,
+    taskId: string,
+  ): Promise<Config> {
+    const workspaceRoot = setTargetDir(agentSettings);
+    loadEnvironment(); // Will override any global env with workspace envs
+    const isTrusted = setIsTrusted(agentSettings);
+    const settings = loadSettings(workspaceRoot, isTrusted);
+    const extensions = loadExtensions(workspaceRoot);
+    return loadConfig(
+      settings,
+      new SimpleExtensionLoader(extensions),
+      taskId,
+      isTrusted,
+    );
+  }
+
+  /**
+   * Reconstructs TaskWrapper from SDKTask.
+   */
+  async reconstruct(
+    sdkTask: SDKTask,
+    eventBus?: ExecutionEventBus,
+  ): Promise<TaskWrapper> {
+    const metadata = sdkTask.metadata || {};
+    const persistedState = getPersistedState(metadata);
+
+    if (!persistedState) {
+      throw new Error(
+        `Cannot reconstruct task ${sdkTask.id}: missing persisted state in metadata.`,
+      );
+    }
+
+    const agentSettings = persistedState._agentSettings;
+    const config = await this.getConfig(agentSettings, sdkTask.id);
+    const contextId: string =
+      getContextIdFromMetadata(metadata) || sdkTask.contextId;
+    const runtimeTask = await Task.create(
+      sdkTask.id,
+      contextId,
+      config,
+      eventBus,
+      agentSettings.autoExecute,
+    );
+    runtimeTask.taskState = persistedState._taskState;
+    await runtimeTask.geminiClient.initialize();
+
+    const wrapper = new TaskWrapper(runtimeTask, agentSettings);
+    this.tasks.set(sdkTask.id, wrapper);
+    logger.info(`Task ${sdkTask.id} reconstructed from store.`);
+    return wrapper;
+  }
+
+  async createTask(
+    taskId: string,
+    contextId: string,
+    agentSettingsInput?: AgentSettings,
+    eventBus?: ExecutionEventBus,
+  ): Promise<TaskWrapper> {
+    const agentSettings: AgentSettings = agentSettingsInput || {
+      kind: CoderAgentEvent.StateAgentSettingsEvent,
+      workspacePath: process.cwd(),
+    };
+    const config = await this.getConfig(agentSettings, taskId);
+    const runtimeTask = await Task.create(
+      taskId,
+      contextId,
+      config,
+      eventBus,
+      agentSettings.autoExecute,
+    );
+    await runtimeTask.geminiClient.initialize();
+
+    const wrapper = new TaskWrapper(runtimeTask, agentSettings);
+    this.tasks.set(taskId, wrapper);
+    logger.info(`New task ${taskId} created.`);
+    return wrapper;
+  }
+
+  getTask(taskId: string): TaskWrapper | undefined {
+    return this.tasks.get(taskId);
+  }
+
+  getAllTasks(): TaskWrapper[] {
+    return Array.from(this.tasks.values());
+  }
+
+  cancelTask = async (
+    taskId: string,
+    eventBus: ExecutionEventBus,
+  ): Promise<void> => {
+    logger.info(
+      `[CoderAgentExecutor] Received cancel request for task ${taskId}`,
+    );
+    const wrapper = this.tasks.get(taskId);
+
+    if (!wrapper) {
+      logger.warn(
+        `[CoderAgentExecutor] Task ${taskId} not found for cancellation.`,
+      );
+      eventBus.publish({
+        kind: 'status-update',
+        taskId,
+        contextId: uuidv4(),
+        status: {
+          state: 'failed',
+          message: {
+            kind: 'message',
+            role: 'agent',
+            parts: [{ kind: 'text', text: `Task ${taskId} not found.` }],
+            messageId: uuidv4(),
+            taskId,
+          },
+        },
+        final: true,
+      });
+      return;
+    }
+
+    const { task } = wrapper;
+
+    if (task.taskState === 'canceled' || task.taskState === 'failed') {
+      logger.info(
+        `[CoderAgentExecutor] Task ${taskId} is already in a final state: ${task.taskState}. No action needed for cancellation.`,
+      );
+      eventBus.publish({
+        kind: 'status-update',
+        taskId,
+        contextId: task.contextId,
+        status: {
+          state: task.taskState,
+          message: {
+            kind: 'message',
+            role: 'agent',
+            parts: [
+              {
+                kind: 'text',
+                text: `Task ${taskId} is already ${task.taskState}.`,
+              },
+            ],
+            messageId: uuidv4(),
+            taskId,
+          },
+        },
+        final: true,
+      });
+      return;
+    }
+
+    try {
+      logger.info(
+        `[CoderAgentExecutor] Initiating cancellation for task ${taskId}.`,
+      );
+      task.cancelPendingTools('Task canceled by user request.');
+
+      const stateChange: StateChange = {
+        kind: CoderAgentEvent.StateChangeEvent,
+      };
+      task.setTaskStateAndPublishUpdate(
+        'canceled',
+        stateChange,
+        'Task canceled by user request.',
+        undefined,
+        true,
+      );
+      logger.info(
+        `[CoderAgentExecutor] Task ${taskId} cancellation processed. Saving state.`,
+      );
+      await this.taskStore?.save(wrapper.toSDKTask());
+      logger.info(`[CoderAgentExecutor] Task ${taskId} state CANCELED saved.`);
+
+      // Cleanup listener subscriptions to avoid memory leaks.
+      wrapper.task.dispose();
+      this.tasks.delete(taskId);
+    } catch (error) {
+      const errorMessage =
+        error instanceof Error ? error.message : 'Unknown error';
+      logger.error(
+        `[CoderAgentExecutor] Error during task cancellation for ${taskId}: ${errorMessage}`,
+        error,
+      );
+      eventBus.publish({
+        kind: 'status-update',
+        taskId,
+        contextId: task.contextId,
+        status: {
+          state: 'failed',
+          message: {
+            kind: 'message',
+            role: 'agent',
+            parts: [
+              {
+                kind: 'text',
+                text: `Failed to process cancellation for task ${taskId}: ${errorMessage}`,
+              },
+            ],
+            messageId: uuidv4(),
+            taskId,
+          },
+        },
+        final: true,
+      });
+    }
+  };
+
+  async execute(
+    requestContext: RequestContext,
+    eventBus: ExecutionEventBus,
+  ): Promise<void> {
+    const userMessage = requestContext.userMessage;
+    const sdkTask = requestContext.task;
+
+    const taskId = sdkTask?.id || userMessage.taskId || uuidv4();
+    const contextId: string =
+      userMessage.contextId ||
+      sdkTask?.contextId ||
+      getContextIdFromMetadata(sdkTask?.metadata) ||
+      uuidv4();
+
+    logger.info(
+      `[CoderAgentExecutor] Executing for taskId: ${taskId}, contextId: ${contextId}`,
+    );
+    logger.info(
+      `[CoderAgentExecutor] userMessage: ${JSON.stringify(userMessage)}`,
+    );
+    eventBus.on('event', (event: AgentExecutionEvent) =>
+      logger.info('[EventBus event]: ', event),
+    );
+
+    const store = requestStorage.getStore();
+    if (!store) {
+      logger.error(
+        '[CoderAgentExecutor] Could not get request from async local storage. Cancellation on socket close will not be handled for this request.',
+      );
+    }
+
+    const abortController = new AbortController();
+    const abortSignal = abortController.signal;
+
+    if (store) {
+      // Grab the raw socket from the request object
+      const socket = store.req.socket;
+      const onSocketEnd = () => {
+        logger.info(
+          `[CoderAgentExecutor] Socket ended for message ${userMessage.messageId} (task ${taskId}). Aborting execution loop.`,
+        );
+        if (!abortController.signal.aborted) {
+          abortController.abort();
+        }
+        // Clean up the listener to prevent memory leaks
+        socket.removeListener('end', onSocketEnd);
+      };
+
+      // Listen on the socket's 'end' event (remote closed the connection)
+      socket.on('end', onSocketEnd);
+      socket.once('close', () => {
+        socket.removeListener('end', onSocketEnd);
+      });
+
+      // It's also good practice to remove the listener if the task completes successfully
+      abortSignal.addEventListener('abort', () => {
+        socket.removeListener('end', onSocketEnd);
+      });
+      logger.info(
+        `[CoderAgentExecutor] Socket close handler set up for task ${taskId}.`,
+      );
+    }
+
+    let wrapper: TaskWrapper | undefined = this.tasks.get(taskId);
+
+    if (wrapper) {
+      wrapper.task.eventBus = eventBus;
+      logger.info(`[CoderAgentExecutor] Task ${taskId} found in memory cache.`);
+    } else if (sdkTask) {
+      logger.info(
+        `[CoderAgentExecutor] Task ${taskId} found in TaskStore. Reconstructing...`,
+      );
+      try {
+        wrapper = await this.reconstruct(sdkTask, eventBus);
+      } catch (e) {
+        logger.error(
+          `[CoderAgentExecutor] Failed to hydrate task ${taskId}:`,
+          e,
+        );
+        const stateChange: StateChange = {
+          kind: CoderAgentEvent.StateChangeEvent,
+        };
+        eventBus.publish({
+          kind: 'status-update',
+          taskId,
+          contextId: sdkTask.contextId,
+          status: {
+            state: 'failed',
+            message: {
+              kind: 'message',
+              role: 'agent',
+              parts: [
+                {
+                  kind: 'text',
+                  text: 'Internal error: Task state lost or corrupted.',
+                },
+              ],
+              messageId: uuidv4(),
+              taskId,
+              contextId: sdkTask.contextId,
+            } as Message,
+          },
+          final: true,
+          metadata: { coderAgent: stateChange },
+        });
+        return;
+      }
+    } else {
+      logger.info(`[CoderAgentExecutor] Creating new task ${taskId}.`);
+      const agentSettings = getAgentSettingsFromMetadata(userMessage.metadata);
+      try {
+        wrapper = await this.createTask(
+          taskId,
+          contextId,
+          agentSettings,
+          eventBus,
+        );
+      } catch (error) {
+        logger.error(
+          `[CoderAgentExecutor] Error creating task ${taskId}:`,
+          error,
+        );
+        // eslint-disable-next-line @typescript-eslint/no-floating-promises
+        pushTaskStateFailed(error, eventBus, taskId, contextId);
+        return;
+      }
+      const newTaskSDK = wrapper.toSDKTask();
+      eventBus.publish({
+        ...newTaskSDK,
+        kind: 'task',
+        status: { state: 'submitted', timestamp: new Date().toISOString() },
+        history: [userMessage],
+      });
+      try {
+        await this.taskStore?.save(newTaskSDK);
+        logger.info(`[CoderAgentExecutor] New task ${taskId} saved to store.`);
+      } catch (saveError) {
+        logger.error(
+          `[CoderAgentExecutor] Failed to save new task ${taskId} to store:`,
+          saveError,
+        );
+      }
+    }
+
+    if (!wrapper) {
+      logger.error(
+        `[CoderAgentExecutor] Task ${taskId} is unexpectedly undefined after load/create.`,
+      );
+      return;
+    }
+
+    const currentTask = wrapper.task;
+
+    if (['canceled', 'failed', 'completed'].includes(currentTask.taskState)) {
+      logger.warn(
+        `[CoderAgentExecutor] Attempted to execute task ${taskId} which is already in state ${currentTask.taskState}. Ignoring.`,
+      );
+      return;
+    }
+
+    if (this.executingTasks.has(taskId)) {
+      logger.info(
+        `[CoderAgentExecutor] Task ${taskId} has a pending execution. Processing message and yielding.`,
+      );
+      currentTask.eventBus = eventBus;
+      for await (const _ of currentTask.acceptUserMessage(
+        requestContext,
+        abortController.signal,
+      )) {
+        logger.info(
+          `[CoderAgentExecutor] Processing user message ${userMessage.messageId} in secondary execution loop for task ${taskId}.`,
+        );
+      }
+      // End this execution-- the original/source will be resumed.
+      return;
+    }
+
+    // Check if this is the primary/initial execution for this task
+    const isPrimaryExecution = !this.executingTasks.has(taskId);
+
+    if (!isPrimaryExecution) {
+      logger.info(
+        `[CoderAgentExecutor] Primary execution already active for task ${taskId}. Starting secondary loop for message ${userMessage.messageId}.`,
+      );
+      currentTask.eventBus = eventBus;
+      for await (const _ of currentTask.acceptUserMessage(
+        requestContext,
+        abortController.signal,
+      )) {
+        logger.info(
+          `[CoderAgentExecutor] Processing user message ${userMessage.messageId} in secondary execution loop for task ${taskId}.`,
+        );
+      }
+      // End this execution-- the original/source will be resumed.
+      return;
+    }
+
+    logger.info(
+      `[CoderAgentExecutor] Starting main execution for message ${userMessage.messageId} for task ${taskId}.`,
+    );
+    this.executingTasks.add(taskId);
+
+    try {
+      let agentTurnActive = true;
+      logger.info(`[CoderAgentExecutor] Task ${taskId}: Processing user turn.`);
+      let agentEvents = currentTask.acceptUserMessage(
+        requestContext,
+        abortSignal,
+      );
+
+      while (agentTurnActive) {
+        logger.info(
+          `[CoderAgentExecutor] Task ${taskId}: Processing agent turn (LLM stream).`,
+        );
+        const toolCallRequests: ToolCallRequestInfo[] = [];
+        for await (const event of agentEvents) {
+          if (abortSignal.aborted) {
+            logger.warn(
+              `[CoderAgentExecutor] Task ${taskId}: Abort signal received during agent event processing.`,
+            );
+            throw new Error('Execution aborted');
+          }
+          if (event.type === GeminiEventType.ToolCallRequest) {
+            toolCallRequests.push(event.value);
+            continue;
+          }
+          await currentTask.acceptAgentMessage(event);
+        }
+
+        if (abortSignal.aborted) throw new Error('Execution aborted');
+
+        if (toolCallRequests.length > 0) {
+          logger.info(
+            `[CoderAgentExecutor] Task ${taskId}: Found ${toolCallRequests.length} tool call requests. Scheduling as a batch.`,
+          );
+          await currentTask.scheduleToolCalls(toolCallRequests, abortSignal);
+        }
+
+        logger.info(
+          `[CoderAgentExecutor] Task ${taskId}: Waiting for pending tools if any.`,
+        );
+        await currentTask.waitForPendingTools();
+        logger.info(
+          `[CoderAgentExecutor] Task ${taskId}: All pending tools completed or none were pending.`,
+        );
+
+        if (abortSignal.aborted) throw new Error('Execution aborted');
+
+        if (currentTask.hasPendingTools) {
+          logger.info(
+            `[CoderAgentExecutor] Task ${taskId}: There are still ${currentTask.pendingToolsCount} pending tools waiting for approval. Yielding to user.`,
+          );
+          agentTurnActive = false;
+        } else {
+          const completedTools = currentTask.getAndClearCompletedTools();
+
+          if (completedTools.length > 0) {
+            // If all completed tool calls were canceled, manually add them to history and set state to input-required, final:true
+            if (completedTools.every((tool) => tool.status === 'cancelled')) {
+              logger.info(
+                `[CoderAgentExecutor] Task ${taskId}: All tool calls were cancelled. Updating history and ending agent turn.`,
+              );
+              currentTask.addToolResponsesToHistory(completedTools);
+              agentTurnActive = false;
+              const stateChange: StateChange = {
+                kind: CoderAgentEvent.StateChangeEvent,
+              };
+              currentTask.setTaskStateAndPublishUpdate(
+                'input-required',
+                stateChange,
+                undefined,
+                undefined,
+                true,
+              );
+            } else {
+              logger.info(
+                `[CoderAgentExecutor] Task ${taskId}: Found ${completedTools.length} completed tool calls. Sending results back to LLM.`,
+              );
+
+              agentEvents = currentTask.sendCompletedToolsToLlm(
+                completedTools,
+                abortSignal,
+              );
+              // Continue the loop to process the LLM response to the tool results.
+            }
+          } else {
+            logger.info(
+              `[CoderAgentExecutor] Task ${taskId}: No more tool calls to process. Ending agent turn.`,
+            );
+            agentTurnActive = false;
+          }
+        }
+      }
+
+      logger.info(
+        `[CoderAgentExecutor] Task ${taskId}: Agent turn finished, setting to input-required.`,
+      );
+      const stateChange: StateChange = {
+        kind: CoderAgentEvent.StateChangeEvent,
+      };
+      currentTask.setTaskStateAndPublishUpdate(
+        'input-required',
+        stateChange,
+        undefined,
+        undefined,
+        true,
+      );
+    } catch (error) {
+      if (abortSignal.aborted) {
+        logger.warn(`[CoderAgentExecutor] Task ${taskId} execution aborted.`);
+        currentTask.cancelPendingTools('Execution aborted');
+        if (
+          currentTask.taskState !== 'canceled' &&
+          currentTask.taskState !== 'failed'
+        ) {
+          currentTask.setTaskStateAndPublishUpdate(
+            'input-required',
+            { kind: CoderAgentEvent.StateChangeEvent },
+            'Execution aborted by client.',
+            undefined,
+            true,
+          );
+        }
+      } else {
+        const errorMessage =
+          error instanceof Error ? error.message : 'Agent execution error';
+        logger.error(
+          `[CoderAgentExecutor] Error executing agent for task ${taskId}:`,
+          error,
+        );
+        currentTask.cancelPendingTools(errorMessage);
+        if (currentTask.taskState !== 'failed') {
+          const stateChange: StateChange = {
+            kind: CoderAgentEvent.StateChangeEvent,
+          };
+          currentTask.setTaskStateAndPublishUpdate(
+            'failed',
+            stateChange,
+            errorMessage,
+            undefined,
+            true,
+          );
+        }
+      }
+    } finally {
+      if (isPrimaryExecution) {
+        this.executingTasks.delete(taskId);
+        logger.info(
+          `[CoderAgentExecutor] Saving final state for task ${taskId}.`,
+        );
+        try {
+          await this.taskStore?.save(wrapper.toSDKTask());
+          logger.info(`[CoderAgentExecutor] Task ${taskId} state saved.`);
+        } catch (saveError) {
+          logger.error(
+            `[CoderAgentExecutor] Failed to save task ${taskId} state in finally block:`,
+            saveError,
+          );
+        }
+
+        if (
+          ['canceled', 'failed', 'completed'].includes(currentTask.taskState)
+        ) {
+          logger.info(
+            `[CoderAgentExecutor] Task ${taskId} reached terminal state ${currentTask.taskState}. Evicting and disposing.`,
+          );
+          wrapper.task.dispose();
+          this.tasks.delete(taskId);
+        }
+      }
+    }
+  }
+}

packages/a2a-server/src/agent/race-condition.test.ts

@@ -0,0 +1,173 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, type Mock } from 'vitest';
+import { Task } from './task.js';
+import {
+  MessageBusType,
+  CoreToolCallStatus,
+  type Config,
+  type MessageBus,
+} from '@google/gemini-cli-core';
+import { createMockConfig } from '../utils/testing_utils.js';
+import type { RequestContext } from '@a2a-js/sdk/server';
+
+describe('Task Race Condition', () => {
+  let mockConfig: Config;
+  let messageBus: MessageBus;
+
+  beforeEach(() => {
+    messageBus = {
+      subscribe: vi.fn(),
+      unsubscribe: vi.fn(),
+      publish: vi.fn(),
+    } as unknown as MessageBus;
+    mockConfig = createMockConfig({
+      messageBus,
+    }) as Config;
+  });
+
+  it('should not hang when multiple tool confirmations are processed while waiting', async () => {
+    // @ts-expect-error - private constructor
+    const task = new Task('task-id', 'context-id', mockConfig);
+
+    // 1. Register two tools as scheduled
+    task['_registerToolCall']('tool-1', 'scheduled');
+    task['_registerToolCall']('tool-2', 'scheduled');
+
+    // 2. Both transition to awaiting_approval
+    const updateHandler = (messageBus.subscribe as Mock).mock.calls.find(
+      (c: unknown[]) => c[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    updateHandler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      schedulerId: 'task-id',
+      toolCalls: [
+        {
+          request: { callId: 'tool-1', name: 't1' },
+          status: CoreToolCallStatus.AwaitingApproval,
+          correlationId: 'corr-1',
+          confirmationDetails: { type: 'info' },
+        },
+        {
+          request: { callId: 'tool-2', name: 't2' },
+          status: CoreToolCallStatus.AwaitingApproval,
+          correlationId: 'corr-2',
+          confirmationDetails: { type: 'info' },
+        },
+      ],
+    });
+
+    // 3. Confirm Tool 1. This makes isAwaitingApprovalOnly() return false.
+    for await (const _ of task.acceptUserMessage(
+      {
+        userMessage: {
+          parts: [
+            {
+              kind: 'data',
+              data: { callId: 'tool-1', outcome: 'proceed_once' },
+            },
+          ],
+        },
+      } as unknown as RequestContext,
+      new AbortController().signal,
+    )) {
+      // consume generator
+    }
+
+    // 4. Start waiting. This should now block because Tool 1 is confirmed (so we are waiting for its execution).
+    const waitPromise = task.waitForPendingTools();
+
+    // 5. Confirm Tool 2 while waiting.
+    for await (const _ of task.acceptUserMessage(
+      {
+        userMessage: {
+          parts: [
+            {
+              kind: 'data',
+              data: { callId: 'tool-2', outcome: 'proceed_once' },
+            },
+          ],
+        },
+      } as unknown as RequestContext,
+      new AbortController().signal,
+    )) {
+      // consume generator
+    }
+
+    // 6. Both tools complete successfully
+    updateHandler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      schedulerId: 'task-id',
+      toolCalls: [
+        {
+          request: { callId: 'tool-1', name: 't1' },
+          status: CoreToolCallStatus.Success,
+          response: { responseParts: [] },
+        },
+        {
+          request: { callId: 'tool-2', name: 't2' },
+          status: CoreToolCallStatus.Success,
+          response: { responseParts: [] },
+        },
+      ],
+    });
+
+    // 7. Verify that the original waitPromise resolves.
+    await expect(waitPromise).resolves.toBeUndefined();
+  });
+
+  it('should reject waitForPendingTools when tools are cancelled', async () => {
+    // @ts-expect-error - private constructor
+    const task = new Task('task-id', 'context-id', mockConfig);
+
+    // 1. Register a tool
+    task['_registerToolCall']('tool-1', 'scheduled');
+
+    // 2. Start waiting
+    const waitPromise = task.waitForPendingTools();
+
+    // 3. Cancel pending tools
+    task.cancelPendingTools('User requested cancellation');
+
+    // 4. Verify waitPromise rejects with the reason
+    await expect(waitPromise).rejects.toThrow('User requested cancellation');
+  });
+
+  it('should handle concurrent tool scheduling correctly', async () => {
+    // @ts-expect-error - private constructor
+    const task = new Task('task-id', 'context-id', mockConfig);
+
+    // 1. Register a tool and start waiting
+    task['_registerToolCall']('tool-1', 'scheduled');
+    const waitPromise = task.waitForPendingTools();
+
+    // 2. Schedule another tool concurrently (e.g. from a secondary user message)
+    // This should NOT resolve the current waitPromise until both are done
+    await task.scheduleToolCalls(
+      [{ callId: 'tool-2', name: 't2', args: {} }],
+      new AbortController().signal,
+    );
+
+    expect(task['pendingToolCalls'].size).toBe(2);
+
+    // 3. Resolve tool 1
+    task['_resolveToolCall']('tool-1');
+
+    // 4. Verify waitPromise is still pending
+    let resolved = false;
+    waitPromise.then(() => (resolved = true));
+    await new Promise((resolve) => setTimeout(resolve, 10));
+    expect(resolved).toBe(false);
+
+    // 5. Resolve tool 2
+    task['_resolveToolCall']('tool-2');
+
+    // 6. Now it should resolve
+    await expect(waitPromise).resolves.toBeUndefined();
+  });
+});

packages/a2a-server/src/agent/task-event-driven.test.ts

@@ -0,0 +1,762 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+import { describe, it, expect, vi, beforeEach, type Mock } from 'vitest';
+import { Task } from './task.js';
+import {
+  type Config,
+  MessageBusType,
+  ToolConfirmationOutcome,
+  ApprovalMode,
+  Scheduler,
+  type MessageBus,
+  type ToolLiveOutput,
+} from '@google/gemini-cli-core';
+import { createMockConfig } from '../utils/testing_utils.js';
+import type { ExecutionEventBus } from '@a2a-js/sdk/server';
+
+describe('Task Event-Driven Scheduler', () => {
+  let mockConfig: Config;
+  let mockEventBus: ExecutionEventBus;
+  let messageBus: MessageBus;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockConfig = createMockConfig({
+      isEventDrivenSchedulerEnabled: () => true,
+    }) as Config;
+    messageBus = mockConfig.messageBus;
+    mockEventBus = {
+      publish: vi.fn(),
+      on: vi.fn(),
+      off: vi.fn(),
+      once: vi.fn(),
+      removeAllListeners: vi.fn(),
+      finished: vi.fn(),
+    };
+  });
+
+  it('should instantiate Scheduler when enabled', () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+    expect(task.scheduler).toBeInstanceOf(Scheduler);
+  });
+
+  it('should subscribe to TOOL_CALLS_UPDATE and map status changes', async () => {
+    // @ts-expect-error - Calling private constructor
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'executing',
+    };
+
+    // Simulate MessageBus event
+    // Simulate MessageBus event
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    if (!handler) {
+      throw new Error('TOOL_CALLS_UPDATE handler not found');
+    }
+
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    expect(mockEventBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        status: expect.objectContaining({
+          state: 'submitted', // initial task state
+        }),
+        metadata: expect.objectContaining({
+          coderAgent: expect.objectContaining({
+            kind: 'tool-call-update',
+          }),
+        }),
+      }),
+    );
+  });
+
+  it('should handle tool confirmations by publishing to MessageBus', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-1',
+      confirmationDetails: { type: 'info', title: 'test', prompt: 'test' },
+    };
+
+    // Simulate MessageBus event to stash the correlationId
+    // Simulate MessageBus event
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    if (!handler) {
+      throw new Error('TOOL_CALLS_UPDATE handler not found');
+    }
+
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    // Simulate A2A client confirmation
+    const part = {
+      kind: 'data',
+      data: {
+        callId: '1',
+        outcome: 'proceed_once',
+      },
+    };
+
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart(part);
+    expect(handled).toBe(true);
+
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-1',
+        confirmed: true,
+        outcome: ToolConfirmationOutcome.ProceedOnce,
+      }),
+    );
+  });
+
+  it('should handle Rejection (Cancel) and Modification (ModifyWithEditor)', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-1',
+      confirmationDetails: { type: 'info', title: 'test', prompt: 'test' },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    // Simulate Rejection (Cancel)
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '1', outcome: 'cancel' },
+    });
+    expect(handled).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-1',
+        confirmed: false,
+      }),
+    );
+
+    const toolCall2 = {
+      request: { callId: '2', name: 'ls', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-2',
+      confirmationDetails: { type: 'info', title: 'test', prompt: 'test' },
+    };
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall2],
+      schedulerId: 'task-id',
+    });
+
+    // Simulate ModifyWithEditor
+    const handled2 = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '2', outcome: 'modify_with_editor' },
+    });
+    expect(handled2).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-2',
+        confirmed: false,
+        outcome: ToolConfirmationOutcome.ModifyWithEditor,
+        payload: undefined,
+      }),
+    );
+  });
+
+  it('should handle MCP Server tool operations correctly', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'call_mcp_tool', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-mcp-1',
+      confirmationDetails: {
+        type: 'mcp',
+        title: 'MCP Server Operation',
+        prompt: 'test_mcp',
+      },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    // Simulate ProceedOnce for MCP
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '1', outcome: 'proceed_once' },
+    });
+    expect(handled).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-mcp-1',
+        confirmed: true,
+        outcome: ToolConfirmationOutcome.ProceedOnce,
+      }),
+    );
+  });
+
+  it('should handle MCP Server tool ProceedAlwaysServer outcome', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'call_mcp_tool', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-mcp-2',
+      confirmationDetails: {
+        type: 'mcp',
+        title: 'MCP Server Operation',
+        prompt: 'test_mcp',
+      },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '1', outcome: 'proceed_always_server' },
+    });
+    expect(handled).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-mcp-2',
+        confirmed: true,
+        outcome: ToolConfirmationOutcome.ProceedAlwaysServer,
+      }),
+    );
+  });
+
+  it('should handle MCP Server tool ProceedAlwaysTool outcome', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'call_mcp_tool', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-mcp-3',
+      confirmationDetails: {
+        type: 'mcp',
+        title: 'MCP Server Operation',
+        prompt: 'test_mcp',
+      },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '1', outcome: 'proceed_always_tool' },
+    });
+    expect(handled).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-mcp-3',
+        confirmed: true,
+        outcome: ToolConfirmationOutcome.ProceedAlwaysTool,
+      }),
+    );
+  });
+
+  it('should handle MCP Server tool ProceedAlwaysAndSave outcome', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'call_mcp_tool', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-mcp-4',
+      confirmationDetails: {
+        type: 'mcp',
+        title: 'MCP Server Operation',
+        prompt: 'test_mcp',
+      },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '1', outcome: 'proceed_always_and_save' },
+    });
+    expect(handled).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-mcp-4',
+        confirmed: true,
+        outcome: ToolConfirmationOutcome.ProceedAlwaysAndSave,
+      }),
+    );
+  });
+
+  it('should execute without confirmation in YOLO mode and not transition to input-required', async () => {
+    // Enable YOLO mode
+    const yoloConfig = createMockConfig({
+      isEventDrivenSchedulerEnabled: () => true,
+      getApprovalMode: () => ApprovalMode.YOLO,
+    }) as Config;
+    const yoloMessageBus = yoloConfig.messageBus;
+
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', yoloConfig, mockEventBus);
+    task.setTaskStateAndPublishUpdate = vi.fn();
+
+    const toolCall = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-1',
+      confirmationDetails: { type: 'info', title: 'test', prompt: 'test' },
+    };
+
+    const handler = (yoloMessageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    // Should NOT auto-publish ProceedOnce anymore, because PolicyEngine handles it directly
+    expect(yoloMessageBus.publish).not.toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+      }),
+    );
+
+    // Should NOT transition to input-required since it was auto-approved
+    expect(task.setTaskStateAndPublishUpdate).not.toHaveBeenCalledWith(
+      'input-required',
+      expect.anything(),
+      undefined,
+      undefined,
+      true,
+    );
+  });
+
+  it('should handle output updates via the message bus', async () => {
+    // @ts-expect-error - Calling private constructor
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'executing',
+      liveOutput: 'chunk1',
+    };
+
+    // Simulate MessageBus event
+    // Simulate MessageBus event
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    if (!handler) {
+      throw new Error('TOOL_CALLS_UPDATE handler not found');
+    }
+
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    // Should publish artifact update for output
+    expect(mockEventBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        kind: 'artifact-update',
+        artifact: expect.objectContaining({
+          artifactId: 'tool-1-output',
+          parts: [{ kind: 'text', text: 'chunk1' }],
+        }),
+      }),
+    );
+  });
+
+  it('should complete artifact creation without hanging', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCallId = 'create-file-123';
+    task['_registerToolCall'](toolCallId, 'executing');
+
+    const toolCall = {
+      request: {
+        callId: toolCallId,
+        name: 'writeFile',
+        args: { path: 'test.sh' },
+      },
+      status: 'success',
+      result: { ok: true },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall],
+      schedulerId: 'task-id',
+    });
+
+    // The tool should be complete and registered appropriately, eventually
+    // triggering the toolCompletionPromise resolution when all clear.
+    const internalTask = task as unknown as {
+      completedToolCalls: unknown[];
+      pendingToolCalls: Map<string, string>;
+    };
+    expect(internalTask.completedToolCalls.length).toBe(1);
+    expect(internalTask.pendingToolCalls.size).toBe(0);
+  });
+
+  it('should preserve messageId across multiple text chunks to prevent UI duplication', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    // Initialize the ID for the first turn (happens internally upon LLM stream)
+    task.currentAgentMessageId = 'test-id-123';
+
+    // Simulate sending multiple text chunks
+    task._sendTextContent('chunk 1');
+    task._sendTextContent('chunk 2');
+
+    // Both text contents should have been published with the same messageId
+    const textCalls = (mockEventBus.publish as Mock).mock.calls.filter(
+      (call) => call[0].status?.message?.kind === 'message',
+    );
+    expect(textCalls.length).toBe(2);
+    expect(textCalls[0][0].status.message.messageId).toBe('test-id-123');
+    expect(textCalls[1][0].status.message.messageId).toBe('test-id-123');
+
+    // Simulate starting a new turn by calling getAndClearCompletedTools
+    // (which precedes sendCompletedToolsToLlm where a new ID is minted)
+    task.getAndClearCompletedTools();
+
+    // sendCompletedToolsToLlm internally rolls the ID forward.
+    // Simulate what sendCompletedToolsToLlm does:
+    const internalTask = task as unknown as {
+      setTaskStateAndPublishUpdate: (state: string, change: unknown) => void;
+    };
+    internalTask.setTaskStateAndPublishUpdate('working', {});
+
+    // Simulate what sendCompletedToolsToLlm does: generate a new UUID for the next turn
+    task.currentAgentMessageId = 'test-id-456';
+
+    task._sendTextContent('chunk 3');
+
+    const secondTurnCalls = (mockEventBus.publish as Mock).mock.calls.filter(
+      (call) => call[0].status?.message?.messageId === 'test-id-456',
+    );
+    expect(secondTurnCalls.length).toBe(1);
+    expect(secondTurnCalls[0][0].status.message.parts[0].text).toBe('chunk 3');
+  });
+
+  it('should handle parallel tool calls correctly', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const toolCall1 = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-1',
+      confirmationDetails: { type: 'info', title: 'test 1', prompt: 'test 1' },
+    };
+
+    const toolCall2 = {
+      request: { callId: '2', name: 'pwd', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-2',
+      confirmationDetails: { type: 'info', title: 'test 2', prompt: 'test 2' },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    // Publish update for both tool calls simultaneously
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall1, toolCall2],
+      schedulerId: 'task-id',
+    });
+
+    // Confirm first tool call
+    const handled1 = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '1', outcome: 'proceed_once' },
+    });
+    expect(handled1).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-1',
+        confirmed: true,
+      }),
+    );
+
+    // Confirm second tool call
+    const handled2 = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: '2', outcome: 'cancel' },
+    });
+    expect(handled2).toBe(true);
+    expect(messageBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        type: MessageBusType.TOOL_CONFIRMATION_RESPONSE,
+        correlationId: 'corr-2',
+        confirmed: false,
+      }),
+    );
+  });
+
+  it('should handle multi-turn tool resolution correctly', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig);
+
+    task['_registerToolCall']('1', 'scheduled');
+    task['_registerToolCall']('2', 'scheduled');
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    // Turn 1: Resolve tool 1
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [
+        {
+          request: { callId: '1', name: 't1' },
+          status: 'success',
+          response: { responseParts: [] },
+        },
+      ],
+      schedulerId: 'task-id',
+    });
+
+    expect(task['pendingToolCalls'].size).toBe(1);
+    expect(task['pendingToolCalls'].has('2')).toBe(true);
+
+    // Turn 2: Resolve tool 2
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [
+        {
+          request: { callId: '2', name: 't2' },
+          status: 'success',
+          response: { responseParts: [] },
+        },
+      ],
+      schedulerId: 'task-id',
+    });
+
+    expect(task['pendingToolCalls'].size).toBe(0);
+  });
+
+  it('should handle subagent progress events from the scheduler', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    // Trigger _schedulerOutputUpdate with subagent progress
+    task['_schedulerOutputUpdate']('tool-1', {
+      isSubagentProgress: true,
+      agentName: 'researcher',
+      recentActivity: [],
+    } as ToolLiveOutput);
+
+    expect(mockEventBus.publish).toHaveBeenCalledWith(
+      expect.objectContaining({
+        kind: 'artifact-update',
+        artifact: expect.objectContaining({
+          parts: [
+            expect.objectContaining({
+              text: expect.stringContaining('researcher'),
+            }),
+          ],
+        }),
+      }),
+    );
+  });
+
+  it('should wait for executing tools before transitioning to input-required state', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    task.setTaskStateAndPublishUpdate = vi.fn();
+
+    // Register tool 1 as executing
+    task['_registerToolCall']('1', 'executing');
+
+    const toolCall1 = {
+      request: { callId: '1', name: 'ls', args: {} },
+      status: 'executing',
+    };
+
+    const toolCall2 = {
+      request: { callId: '2', name: 'pwd', args: {} },
+      status: 'awaiting_approval',
+      correlationId: 'corr-2',
+      confirmationDetails: { type: 'info', title: 'test 2', prompt: 'test 2' },
+    };
+
+    const handler = (messageBus.subscribe as Mock).mock.calls.find(
+      (call: unknown[]) => call[0] === MessageBusType.TOOL_CALLS_UPDATE,
+    )?.[1];
+
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall1, toolCall2],
+      schedulerId: 'task-id',
+    });
+
+    // Should NOT transition to input-required yet
+    expect(task.setTaskStateAndPublishUpdate).not.toHaveBeenCalledWith(
+      'input-required',
+      expect.anything(),
+      undefined,
+      undefined,
+      true,
+    );
+
+    // Complete tool 1
+    const toolCall1Complete = {
+      ...toolCall1,
+      status: 'success',
+      result: { ok: true },
+    };
+
+    handler({
+      type: MessageBusType.TOOL_CALLS_UPDATE,
+      toolCalls: [toolCall1Complete, toolCall2],
+      schedulerId: 'task-id',
+    });
+
+    // Now it should transition
+    expect(task.setTaskStateAndPublishUpdate).toHaveBeenCalledWith(
+      'input-required',
+      expect.anything(),
+      undefined,
+      undefined,
+      true,
+    );
+  });
+
+  it('should ignore confirmations for unknown tool calls', async () => {
+    // @ts-expect-error - Calling private constructor
+    const task = new Task('task-id', 'context-id', mockConfig, mockEventBus);
+
+    const handled = await (
+      task as unknown as {
+        _handleToolConfirmationPart: (part: unknown) => Promise<boolean>;
+      }
+    )._handleToolConfirmationPart({
+      kind: 'data',
+      data: { callId: 'unknown-id', outcome: 'proceed_once' },
+    });
+
+    // Should return false for unhandled tool call
+    expect(handled).toBe(false);
+
+    // Should not publish anything to the message bus
+    expect(messageBus.publish).not.toHaveBeenCalled();
+  });
+});

packages/a2a-server/src/agent/task.test.ts

@@ -0,0 +1,755 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, type Mock } from 'vitest';
+import { Task } from './task.js';
+import {
+  GeminiEventType,
+  type Config,
+  type ToolCallRequestInfo,
+  type GitService,
+  type CompletedToolCall,
+  type ToolCall,
+  type ToolCallsUpdateMessage,
+  MessageBusType,
+} from '@google/gemini-cli-core';
+import { createMockConfig } from '../utils/testing_utils.js';
+import type { ExecutionEventBus, RequestContext } from '@a2a-js/sdk/server';
+import { CoderAgentEvent } from '../types.js';
+
+const mockProcessRestorableToolCalls = vi.hoisted(() => vi.fn());
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...original,
+    processRestorableToolCalls: mockProcessRestorableToolCalls,
+  };
+});
+
+describe('Task', () => {
+  it('scheduleToolCalls should not modify the input requests array', async () => {
+    const mockConfig = createMockConfig();
+
+    const mockEventBus: ExecutionEventBus = {
+      publish: vi.fn(),
+      on: vi.fn(),
+      off: vi.fn(),
+      once: vi.fn(),
+      removeAllListeners: vi.fn(),
+      finished: vi.fn(),
+    };
+
+    // The Task constructor is private. We'll bypass it for this unit test.
+    // @ts-expect-error - Calling private constructor for test purposes.
+    const task = new Task(
+      'task-id',
+      'context-id',
+      mockConfig as Config,
+      mockEventBus,
+    );
+
+    task['setTaskStateAndPublishUpdate'] = vi.fn();
+    task['getProposedContent'] = vi.fn().mockResolvedValue('new content');
+
+    const requests: ToolCallRequestInfo[] = [
+      {
+        callId: '1',
+        name: 'replace',
+        args: {
+          file_path: 'test.txt',
+          old_string: 'old',
+          new_string: 'new',
+        },
+        isClientInitiated: false,
+        prompt_id: 'prompt-id-1',
+      },
+    ];
+
+    const originalRequests = JSON.parse(JSON.stringify(requests));
+    const abortController = new AbortController();
+
+    await task.scheduleToolCalls(requests, abortController.signal);
+
+    expect(requests).toEqual(originalRequests);
+  });
+
+  describe('scheduleToolCalls', () => {
+    const mockConfig = createMockConfig();
+    const mockEventBus: ExecutionEventBus = {
+      publish: vi.fn(),
+      on: vi.fn(),
+      off: vi.fn(),
+      once: vi.fn(),
+      removeAllListeners: vi.fn(),
+      finished: vi.fn(),
+    };
+
+    beforeEach(() => {
+      vi.clearAllMocks();
+    });
+
+    it('should not create a checkpoint if no restorable tools are called', async () => {
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+      const requests: ToolCallRequestInfo[] = [
+        {
+          callId: '1',
+          name: 'run_shell_command',
+          args: { command: 'ls' },
+          isClientInitiated: false,
+          prompt_id: 'prompt-id-1',
+        },
+      ];
+      const abortController = new AbortController();
+      await task.scheduleToolCalls(requests, abortController.signal);
+      expect(mockProcessRestorableToolCalls).not.toHaveBeenCalled();
+    });
+
+    it('should create a checkpoint if a restorable tool is called', async () => {
+      const mockConfig = createMockConfig({
+        getCheckpointingEnabled: () => true,
+        getGitService: () => Promise.resolve({} as GitService),
+      });
+      mockProcessRestorableToolCalls.mockResolvedValue({
+        checkpointsToWrite: new Map([['test.json', 'test content']]),
+        toolCallToCheckpointMap: new Map(),
+        errors: [],
+      });
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+      const requests: ToolCallRequestInfo[] = [
+        {
+          callId: '1',
+          name: 'replace',
+          args: {
+            file_path: 'test.txt',
+            old_string: 'old',
+            new_string: 'new',
+          },
+          isClientInitiated: false,
+          prompt_id: 'prompt-id-1',
+        },
+      ];
+      const abortController = new AbortController();
+      await task.scheduleToolCalls(requests, abortController.signal);
+      expect(mockProcessRestorableToolCalls).toHaveBeenCalledOnce();
+    });
+
+    it('should process all restorable tools for checkpointing in a single batch', async () => {
+      const mockConfig = createMockConfig({
+        getCheckpointingEnabled: () => true,
+        getGitService: () => Promise.resolve({} as GitService),
+      });
+      mockProcessRestorableToolCalls.mockResolvedValue({
+        checkpointsToWrite: new Map([
+          ['test1.json', 'test content 1'],
+          ['test2.json', 'test content 2'],
+        ]),
+        toolCallToCheckpointMap: new Map([
+          ['1', 'test1'],
+          ['2', 'test2'],
+        ]),
+        errors: [],
+      });
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+      const requests: ToolCallRequestInfo[] = [
+        {
+          callId: '1',
+          name: 'replace',
+          args: {
+            file_path: 'test.txt',
+            old_string: 'old',
+            new_string: 'new',
+          },
+          isClientInitiated: false,
+          prompt_id: 'prompt-id-1',
+        },
+        {
+          callId: '2',
+          name: 'write_file',
+          args: { file_path: 'test2.txt', content: 'new content' },
+          isClientInitiated: false,
+          prompt_id: 'prompt-id-2',
+        },
+        {
+          callId: '3',
+          name: 'not_restorable',
+          args: {},
+          isClientInitiated: false,
+          prompt_id: 'prompt-id-3',
+        },
+      ];
+      const abortController = new AbortController();
+      await task.scheduleToolCalls(requests, abortController.signal);
+      expect(mockProcessRestorableToolCalls).toHaveBeenCalledExactlyOnceWith(
+        [
+          expect.objectContaining({ callId: '1' }),
+          expect.objectContaining({ callId: '2' }),
+        ],
+        expect.anything(),
+        expect.anything(),
+      );
+    });
+  });
+
+  describe('acceptAgentMessage', () => {
+    it('should set currentTraceId when event has traceId', async () => {
+      const mockConfig = createMockConfig();
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const event = {
+        type: 'content',
+        value: 'test',
+        traceId: 'test-trace-id',
+      };
+
+      await task.acceptAgentMessage(event);
+
+      expect(mockEventBus.publish).toHaveBeenCalledWith(
+        expect.objectContaining({
+          metadata: expect.objectContaining({
+            traceId: 'test-trace-id',
+          }),
+        }),
+      );
+    });
+
+    it('should handle Citation event and publish to event bus', async () => {
+      const mockConfig = createMockConfig();
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const citationText = 'Source: example.com';
+      const citationEvent = {
+        type: GeminiEventType.Citation,
+        value: citationText,
+      };
+
+      await task.acceptAgentMessage(citationEvent);
+
+      expect(mockEventBus.publish).toHaveBeenCalledOnce();
+      const publishedEvent = (mockEventBus.publish as Mock).mock.calls[0][0];
+
+      expect(publishedEvent.kind).toBe('status-update');
+      expect(publishedEvent.taskId).toBe('task-id');
+      expect(publishedEvent.metadata.coderAgent.kind).toBe(
+        CoderAgentEvent.CitationEvent,
+      );
+      expect(publishedEvent.status.message).toBeDefined();
+      expect(publishedEvent.status.message.parts).toEqual([
+        {
+          kind: 'text',
+          text: citationText,
+        },
+      ]);
+    });
+
+    it('should capture usageMetadata on Finished event and include it in final status update', async () => {
+      const mockConfig = createMockConfig();
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const finishedEvent = {
+        type: GeminiEventType.Finished,
+        value: {
+          reason: 'STOP',
+          usageMetadata: {
+            promptTokenCount: 100,
+            candidatesTokenCount: 50,
+            totalTokenCount: 150,
+          },
+        },
+      };
+
+      await task.acceptAgentMessage(finishedEvent);
+      expect(task.usageMetadata).toEqual({
+        promptTokenCount: 100,
+        candidatesTokenCount: 50,
+        totalTokenCount: 150,
+      });
+
+      task.setTaskStateAndPublishUpdate(
+        'input-required',
+        { kind: CoderAgentEvent.StateChangeEvent },
+        undefined,
+        undefined,
+        true, // final
+      );
+
+      expect(mockEventBus.publish).toHaveBeenCalledWith(
+        expect.objectContaining({
+          final: true,
+          metadata: expect.objectContaining({
+            usageMetadata: {
+              promptTokenCount: 100,
+              candidatesTokenCount: 50,
+              totalTokenCount: 150,
+            },
+          }),
+        }),
+      );
+    });
+
+    it('should update modelInfo and reflect it in metadata and status updates', async () => {
+      const mockConfig = createMockConfig();
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor for test purposes.
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const modelInfoEvent = {
+        type: GeminiEventType.ModelInfo,
+        value: 'new-model-name',
+      };
+
+      await task.acceptAgentMessage(modelInfoEvent);
+
+      expect(task.modelInfo).toBe('new-model-name');
+
+      // Check getMetadata
+      const metadata = await task.getMetadata();
+      expect(metadata.model).toBe('new-model-name');
+
+      // Check status update
+      task.setTaskStateAndPublishUpdate(
+        'working',
+        { kind: CoderAgentEvent.StateChangeEvent },
+        'Working...',
+      );
+
+      expect(mockEventBus.publish).toHaveBeenCalledWith(
+        expect.objectContaining({
+          metadata: expect.objectContaining({
+            model: 'new-model-name',
+          }),
+        }),
+      );
+    });
+
+    it.each([
+      { eventType: GeminiEventType.Retry, eventName: 'Retry' },
+      { eventType: GeminiEventType.InvalidStream, eventName: 'InvalidStream' },
+    ])(
+      'should handle $eventName event without triggering error handling',
+      async ({ eventType }) => {
+        const mockConfig = createMockConfig();
+        const mockEventBus: ExecutionEventBus = {
+          publish: vi.fn(),
+          on: vi.fn(),
+          off: vi.fn(),
+          once: vi.fn(),
+          removeAllListeners: vi.fn(),
+          finished: vi.fn(),
+        };
+
+        // @ts-expect-error - Calling private constructor
+        const task = new Task(
+          'task-id',
+          'context-id',
+          mockConfig as Config,
+          mockEventBus,
+        );
+
+        const cancelPendingToolsSpy = vi.spyOn(task, 'cancelPendingTools');
+        const setTaskStateSpy = vi.spyOn(task, 'setTaskStateAndPublishUpdate');
+
+        const event = {
+          type: eventType,
+        };
+
+        await task.acceptAgentMessage(event);
+
+        expect(cancelPendingToolsSpy).not.toHaveBeenCalled();
+        expect(setTaskStateSpy).not.toHaveBeenCalled();
+      },
+    );
+  });
+
+  describe('currentPromptId and promptCount', () => {
+    it('should correctly initialize and update promptId and promptCount', async () => {
+      const mockConfig = createMockConfig();
+      mockConfig.getGeminiClient = vi.fn().mockReturnValue({
+        sendMessageStream: vi.fn().mockReturnValue((async function* () {})()),
+      });
+      mockConfig.getSessionId = () => 'test-session-id';
+
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      // Initial state
+      expect(task.currentPromptId).toBeUndefined();
+      expect(task.promptCount).toBe(0);
+
+      // First user message should set prompt_id
+      const userMessage1 = {
+        userMessage: {
+          parts: [{ kind: 'text', text: 'hello' }],
+        },
+      } as RequestContext;
+      const abortController1 = new AbortController();
+      for await (const _ of task.acceptUserMessage(
+        userMessage1,
+        abortController1.signal,
+      )) {
+        // no-op
+      }
+
+      const expectedPromptId1 = 'test-session-id########0';
+      expect(task.promptCount).toBe(1);
+      expect(task.currentPromptId).toBe(expectedPromptId1);
+
+      // A new user message should generate a new prompt_id
+      const userMessage2 = {
+        userMessage: {
+          parts: [{ kind: 'text', text: 'world' }],
+        },
+      } as RequestContext;
+      const abortController2 = new AbortController();
+      for await (const _ of task.acceptUserMessage(
+        userMessage2,
+        abortController2.signal,
+      )) {
+        // no-op
+      }
+
+      const expectedPromptId2 = 'test-session-id########1';
+      expect(task.promptCount).toBe(2);
+      expect(task.currentPromptId).toBe(expectedPromptId2);
+
+      // Subsequent tool call processing should use the same prompt_id
+      const completedTool = {
+        request: { callId: 'tool-1' },
+        response: { responseParts: [{ text: 'tool output' }] },
+      } as CompletedToolCall;
+      const abortController3 = new AbortController();
+      for await (const _ of task.sendCompletedToolsToLlm(
+        [completedTool],
+        abortController3.signal,
+      )) {
+        // no-op
+      }
+
+      expect(task.promptCount).toBe(2);
+      expect(task.currentPromptId).toBe(expectedPromptId2);
+    });
+  });
+
+  describe('Race Condition Fix', () => {
+    const mockConfig = createMockConfig();
+    const mockEventBus: ExecutionEventBus = {
+      publish: vi.fn(),
+      on: vi.fn(),
+      off: vi.fn(),
+      once: vi.fn(),
+      removeAllListeners: vi.fn(),
+      finished: vi.fn(),
+    };
+
+    beforeEach(() => {
+      vi.clearAllMocks();
+    });
+
+    it('should NOT transition to input-required if a tool is still validating', async () => {
+      // @ts-expect-error - Calling private constructor
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      // Manually register two tool calls
+      task['_registerToolCall']('tool-1', 'awaiting_approval');
+      task['_registerToolCall']('tool-2', 'validating');
+
+      // Call checkInputRequiredState (private)
+      task['checkInputRequiredState']();
+
+      // Verify task state did NOT change to input-required
+      expect(task.taskState).not.toBe('input-required');
+      expect(mockEventBus.publish).not.toHaveBeenCalledWith(
+        expect.objectContaining({
+          status: expect.objectContaining({ state: 'input-required' }),
+        }),
+      );
+    });
+
+    it('should transition to input-required if all active tools are awaiting approval', async () => {
+      // @ts-expect-error - Calling private constructor
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      // Transition from submitted to working first to simulate normal flow
+      task.taskState = 'working';
+
+      // Manually register tool calls
+      task['_registerToolCall']('tool-1', 'awaiting_approval');
+
+      // Call checkInputRequiredState
+      task['checkInputRequiredState']();
+
+      // Verify task state changed to input-required
+      expect(task.taskState).toBe('input-required');
+      expect(mockEventBus.publish).toHaveBeenCalledWith(
+        expect.objectContaining({
+          status: expect.objectContaining({ state: 'input-required' }),
+        }),
+      );
+    });
+
+    it('handleEventDrivenToolCallsUpdate should ignore events for other schedulers', async () => {
+      // @ts-expect-error - Calling private constructor
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const handleEventDrivenToolCallSpy = vi.spyOn(
+        task as unknown as {
+          handleEventDrivenToolCall: Task['handleEventDrivenToolCall'];
+        },
+        'handleEventDrivenToolCall',
+      );
+
+      const otherEvent: ToolCallsUpdateMessage = {
+        type: MessageBusType.TOOL_CALLS_UPDATE,
+        toolCalls: [
+          { request: { callId: '1' }, status: 'executing' } as ToolCall,
+        ],
+        schedulerId: 'other-task-id',
+      };
+
+      task['handleEventDrivenToolCallsUpdate'](otherEvent);
+
+      expect(handleEventDrivenToolCallSpy).not.toHaveBeenCalled();
+
+      const ownEvent: ToolCallsUpdateMessage = {
+        type: MessageBusType.TOOL_CALLS_UPDATE,
+        toolCalls: [
+          { request: { callId: '1' }, status: 'executing' } as ToolCall,
+        ],
+        schedulerId: 'task-id',
+      };
+
+      task['handleEventDrivenToolCallsUpdate'](ownEvent);
+
+      expect(handleEventDrivenToolCallSpy).toHaveBeenCalled();
+    });
+
+    describe('Pending Tools state', () => {
+      it('should correctly report pending tools presence and count', () => {
+        const mockConfig = createMockConfig();
+        const mockEventBus: ExecutionEventBus = {
+          publish: vi.fn(),
+          on: vi.fn(),
+          off: vi.fn(),
+          once: vi.fn(),
+          removeAllListeners: vi.fn(),
+          finished: vi.fn(),
+        };
+
+        // @ts-expect-error - Calling private constructor
+        const task = new Task(
+          'task-id',
+          'context-id',
+          mockConfig as Config,
+          mockEventBus,
+        );
+
+        expect(task.hasPendingTools).toBe(false);
+        expect(task.pendingToolsCount).toBe(0);
+
+        task['_registerToolCall']('tool-1', 'scheduled');
+        expect(task.hasPendingTools).toBe(true);
+        expect(task.pendingToolsCount).toBe(1);
+      });
+    });
+  });
+
+  describe('Serialization and Mapping', () => {
+    it('should map internal "validating" status to "scheduled" for the client and include outcome', async () => {
+      const mockConfig = createMockConfig();
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const mockToolCall = {
+        request: { callId: 'tool-1' },
+        status: 'validating',
+        outcome: 'accepted',
+        tool: { name: 'test-tool' },
+      };
+
+      const message = task['toolStatusMessage'](
+        mockToolCall as unknown as ToolCall,
+        'task-id',
+        'context-id',
+      );
+      const serialized = (
+        message.parts![0] as {
+          data: { status: string; outcome: string };
+        }
+      ).data;
+
+      expect(serialized.status).toBe('scheduled');
+      expect(serialized.outcome).toBe('accepted');
+    });
+
+    it('should correctly detect changes when status or outcome changes', async () => {
+      const mockConfig = createMockConfig();
+      const mockEventBus: ExecutionEventBus = {
+        publish: vi.fn(),
+        on: vi.fn(),
+        off: vi.fn(),
+        once: vi.fn(),
+        removeAllListeners: vi.fn(),
+        finished: vi.fn(),
+      };
+
+      // @ts-expect-error - Calling private constructor
+      const task = new Task(
+        'task-id',
+        'context-id',
+        mockConfig as Config,
+        mockEventBus,
+      );
+
+      const toolCall1 = {
+        request: { callId: 'tool-1' },
+        status: 'awaiting_approval',
+      };
+
+      // First update - should trigger change
+      const changed1 = task['handleEventDrivenToolCall'](
+        toolCall1 as unknown as ToolCall,
+      );
+      expect(changed1).toBe(true);
+
+      // Second update with same status - should NOT trigger change
+      const changed2 = task['handleEventDrivenToolCall'](
+        toolCall1 as unknown as ToolCall,
+      );
+      expect(changed2).toBe(false);
+
+      // Update with new outcome - SHOULD trigger change
+      const toolCall2 = {
+        request: { callId: 'tool-1' },
+        status: 'awaiting_approval',
+        outcome: 'accepted',
+      };
+      const changed3 = task['handleEventDrivenToolCall'](
+        toolCall2 as unknown as ToolCall,
+      );
+      expect(changed3).toBe(true);
+    });
+  });
+});

packages/a2a-server/src/commands/command-registry.test.ts

@@ -0,0 +1,142 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import type { Command } from './types.js';
+
+const {
+  mockExtensionsCommand,
+  mockListExtensionsCommand,
+  mockExtensionsCommandInstance,
+  mockListExtensionsCommandInstance,
+} = vi.hoisted(() => {
+  const listInstance: Command = {
+    name: 'extensions list',
+    description: 'Lists all installed extensions.',
+    execute: vi.fn(),
+  };
+
+  const extInstance: Command = {
+    name: 'extensions',
+    description: 'Manage extensions.',
+    execute: vi.fn(),
+    subCommands: [listInstance],
+  };
+
+  return {
+    mockListExtensionsCommandInstance: listInstance,
+    mockExtensionsCommandInstance: extInstance,
+    mockExtensionsCommand: vi.fn(() => extInstance),
+    mockListExtensionsCommand: vi.fn(() => listInstance),
+  };
+});
+
+vi.mock('./extensions.js', () => ({
+  ExtensionsCommand: mockExtensionsCommand,
+  ListExtensionsCommand: mockListExtensionsCommand,
+}));
+
+vi.mock('./init.js', () => ({
+  InitCommand: vi.fn(() => ({
+    name: 'init',
+    description: 'Initializes the server.',
+    execute: vi.fn(),
+  })),
+}));
+
+vi.mock('./restore.js', () => ({
+  RestoreCommand: vi.fn(() => ({
+    name: 'restore',
+    description: 'Restores the server.',
+    execute: vi.fn(),
+  })),
+}));
+
+import { commandRegistry } from './command-registry.js';
+
+describe('CommandRegistry', () => {
+  beforeEach(async () => {
+    vi.clearAllMocks();
+    commandRegistry.initialize();
+  });
+
+  it('should register ExtensionsCommand on initialization', async () => {
+    expect(mockExtensionsCommand).toHaveBeenCalled();
+    const command = commandRegistry.get('extensions');
+    expect(command).toBe(mockExtensionsCommandInstance);
+  }, 20000);
+
+  it('should register sub commands on initialization', async () => {
+    const command = commandRegistry.get('extensions list');
+    expect(command).toBe(mockListExtensionsCommandInstance);
+  });
+
+  it('get() should return undefined for a non-existent command', async () => {
+    const command = commandRegistry.get('non-existent');
+    expect(command).toBeUndefined();
+  });
+
+  it('register() should register a new command', async () => {
+    const mockCommand: Command = {
+      name: 'test-command',
+      description: '',
+      execute: vi.fn(),
+    };
+    commandRegistry.register(mockCommand);
+    const command = commandRegistry.get('test-command');
+    expect(command).toBe(mockCommand);
+  });
+
+  it('register() should register a nested command', async () => {
+    const mockSubSubCommand: Command = {
+      name: 'test-command-sub-sub',
+      description: '',
+      execute: vi.fn(),
+    };
+    const mockSubCommand: Command = {
+      name: 'test-command-sub',
+      description: '',
+      execute: vi.fn(),
+      subCommands: [mockSubSubCommand],
+    };
+    const mockCommand: Command = {
+      name: 'test-command',
+      description: '',
+      execute: vi.fn(),
+      subCommands: [mockSubCommand],
+    };
+    commandRegistry.register(mockCommand);
+
+    const command = commandRegistry.get('test-command');
+    const subCommand = commandRegistry.get('test-command-sub');
+    const subSubCommand = commandRegistry.get('test-command-sub-sub');
+
+    expect(command).toBe(mockCommand);
+    expect(subCommand).toBe(mockSubCommand);
+    expect(subSubCommand).toBe(mockSubSubCommand);
+  });
+
+  it('register() should not enter an infinite loop with a cyclic command', async () => {
+    const { debugLogger } = await import('@google/gemini-cli-core');
+    const warnSpy = vi.spyOn(debugLogger, 'warn').mockImplementation(() => {});
+    const mockCommand: Command = {
+      name: 'cyclic-command',
+      description: '',
+      subCommands: [],
+      execute: vi.fn(),
+    };
+
+    mockCommand.subCommands?.push(mockCommand); // Create cycle
+
+    commandRegistry.register(mockCommand);
+
+    expect(commandRegistry.get('cyclic-command')).toBe(mockCommand);
+    expect(warnSpy).toHaveBeenCalledWith(
+      'Command cyclic-command already registered. Skipping.',
+    );
+    warnSpy.mockRestore();
+  });
+});

packages/a2a-server/src/commands/command-registry.ts

@@ -0,0 +1,51 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { MemoryCommand } from './memory.js';
+import { debugLogger } from '@google/gemini-cli-core';
+import { ExtensionsCommand } from './extensions.js';
+import { InitCommand } from './init.js';
+import { RestoreCommand } from './restore.js';
+import type { Command } from './types.js';
+
+export class CommandRegistry {
+  private readonly commands = new Map<string, Command>();
+
+  constructor() {
+    this.initialize();
+  }
+
+  initialize() {
+    this.commands.clear();
+    this.register(new ExtensionsCommand());
+    this.register(new RestoreCommand());
+    this.register(new InitCommand());
+    this.register(new MemoryCommand());
+  }
+
+  register(command: Command) {
+    if (this.commands.has(command.name)) {
+      debugLogger.warn(`Command ${command.name} already registered. Skipping.`);
+      return;
+    }
+
+    this.commands.set(command.name, command);
+
+    for (const subCommand of command.subCommands ?? []) {
+      this.register(subCommand);
+    }
+  }
+
+  get(commandName: string): Command | undefined {
+    return this.commands.get(commandName);
+  }
+
+  getAllCommands(): Command[] {
+    return [...this.commands.values()];
+  }
+}
+
+export const commandRegistry = new CommandRegistry();

packages/a2a-server/src/commands/extensions.test.ts

@@ -0,0 +1,87 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi } from 'vitest';
+import { ExtensionsCommand, ListExtensionsCommand } from './extensions.js';
+import type { CommandContext } from './types.js';
+
+const mockListExtensions = vi.hoisted(() => vi.fn());
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+
+  return {
+    ...original,
+    listExtensions: mockListExtensions,
+  };
+});
+
+describe('ExtensionsCommand', () => {
+  it('should have the correct name', () => {
+    const command = new ExtensionsCommand();
+    expect(command.name).toEqual('extensions');
+  });
+
+  it('should have the correct description', () => {
+    const command = new ExtensionsCommand();
+    expect(command.description).toEqual('Manage extensions.');
+  });
+
+  it('should have "extensions list" as a subcommand', () => {
+    const command = new ExtensionsCommand();
+    expect(command.subCommands.map((c) => c.name)).toContain('extensions list');
+  });
+
+  it('should be a top-level command', () => {
+    const command = new ExtensionsCommand();
+    expect(command.topLevel).toBe(true);
+  });
+
+  it('should default to listing extensions', async () => {
+    const command = new ExtensionsCommand();
+    const mockConfig = { config: {} } as CommandContext;
+    const mockExtensions = [{ name: 'ext1' }];
+    mockListExtensions.mockReturnValue(mockExtensions);
+
+    const result = await command.execute(mockConfig, []);
+
+    expect(result).toEqual({ name: 'extensions list', data: mockExtensions });
+    expect(mockListExtensions).toHaveBeenCalledWith(mockConfig.config);
+  });
+});
+
+describe('ListExtensionsCommand', () => {
+  it('should have the correct name', () => {
+    const command = new ListExtensionsCommand();
+    expect(command.name).toEqual('extensions list');
+  });
+
+  it('should call listExtensions with the provided config', async () => {
+    const command = new ListExtensionsCommand();
+    const mockConfig = { config: {} } as CommandContext;
+    const mockExtensions = [{ name: 'ext1' }];
+    mockListExtensions.mockReturnValue(mockExtensions);
+
+    const result = await command.execute(mockConfig, []);
+
+    expect(result).toEqual({ name: 'extensions list', data: mockExtensions });
+    expect(mockListExtensions).toHaveBeenCalledWith(mockConfig.config);
+  });
+
+  it('should return a message when no extensions are installed', async () => {
+    const command = new ListExtensionsCommand();
+    const mockConfig = { config: {} } as CommandContext;
+    mockListExtensions.mockReturnValue([]);
+
+    const result = await command.execute(mockConfig, []);
+
+    expect(result).toEqual({
+      name: 'extensions list',
+      data: 'No extensions installed.',
+    });
+    expect(mockListExtensions).toHaveBeenCalledWith(mockConfig.config);
+  });
+});

packages/a2a-server/src/commands/extensions.ts

@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { listExtensions } from '@google/gemini-cli-core';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class ExtensionsCommand implements Command {
+  readonly name = 'extensions';
+  readonly description = 'Manage extensions.';
+  readonly subCommands = [new ListExtensionsCommand()];
+  readonly topLevel = true;
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    return new ListExtensionsCommand().execute(context, _);
+  }
+}
+
+export class ListExtensionsCommand implements Command {
+  readonly name = 'extensions list';
+  readonly description = 'Lists all installed extensions.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensions = listExtensions(context.config);
+    const data = extensions.length ? extensions : 'No extensions installed.';
+
+    return { name: this.name, data };
+  }
+}

packages/a2a-server/src/commands/init.test.ts

@@ -0,0 +1,189 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { InitCommand } from './init.js';
+import {
+  performInit,
+  type CommandActionReturn,
+  type Config,
+} from '@google/gemini-cli-core';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import { CoderAgentExecutor } from '../agent/executor.js';
+import { CoderAgentEvent } from '../types.js';
+import type { ExecutionEventBus } from '@a2a-js/sdk/server';
+import { createMockConfig } from '../utils/testing_utils.js';
+import type { CommandContext } from './types.js';
+import { logger } from '../utils/logger.js';
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    performInit: vi.fn(),
+  };
+});
+
+vi.mock('node:fs', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('node:fs')>();
+  return {
+    ...actual,
+    existsSync: vi.fn(),
+    writeFileSync: vi.fn(),
+  };
+});
+
+vi.mock('../agent/executor.js', () => ({
+  CoderAgentExecutor: vi.fn().mockImplementation(() => ({
+    execute: vi.fn(),
+  })),
+}));
+
+vi.mock('../utils/logger.js', () => ({
+  logger: {
+    info: vi.fn(),
+    error: vi.fn(),
+  },
+}));
+
+describe('InitCommand', () => {
+  let eventBus: ExecutionEventBus;
+  let command: InitCommand;
+  let context: CommandContext;
+  let publishSpy: ReturnType<typeof vi.spyOn>;
+  let mockExecute: ReturnType<typeof vi.fn>;
+  const mockWorkspacePath = path.resolve('/tmp');
+
+  beforeEach(() => {
+    process.env['CODER_AGENT_WORKSPACE_PATH'] = mockWorkspacePath;
+    eventBus = {
+      publish: vi.fn(),
+    } as unknown as ExecutionEventBus;
+    command = new InitCommand();
+    const mockConfig = createMockConfig({
+      getModel: () => 'gemini-pro',
+    });
+    const mockExecutorInstance = new CoderAgentExecutor();
+    context = {
+      config: mockConfig as unknown as Config,
+      agentExecutor: mockExecutorInstance,
+      eventBus,
+    } as CommandContext;
+    publishSpy = vi.spyOn(eventBus, 'publish');
+    mockExecute = vi.fn();
+    vi.spyOn(mockExecutorInstance, 'execute').mockImplementation(mockExecute);
+    vi.clearAllMocks();
+  });
+
+  it('has requiresWorkspace set to true', () => {
+    expect(command.requiresWorkspace).toBe(true);
+  });
+
+  describe('execute', () => {
+    it('handles info from performInit', async () => {
+      vi.mocked(performInit).mockReturnValue({
+        type: 'message',
+        messageType: 'info',
+        content: 'GEMINI.md already exists.',
+      } as CommandActionReturn);
+
+      await command.execute(context, []);
+
+      expect(logger.info).toHaveBeenCalledWith(
+        '[EventBus event]: ',
+        expect.objectContaining({
+          kind: 'status-update',
+          status: expect.objectContaining({
+            state: 'completed',
+            message: expect.objectContaining({
+              parts: [{ kind: 'text', text: 'GEMINI.md already exists.' }],
+            }),
+          }),
+        }),
+      );
+
+      expect(publishSpy).toHaveBeenCalledWith(
+        expect.objectContaining({
+          kind: 'status-update',
+          status: expect.objectContaining({
+            state: 'completed',
+            message: expect.objectContaining({
+              parts: [{ kind: 'text', text: 'GEMINI.md already exists.' }],
+            }),
+          }),
+        }),
+      );
+    });
+
+    it('handles error from performInit', async () => {
+      vi.mocked(performInit).mockReturnValue({
+        type: 'message',
+        messageType: 'error',
+        content: 'An error occurred.',
+      } as CommandActionReturn);
+
+      await command.execute(context, []);
+
+      expect(publishSpy).toHaveBeenCalledWith(
+        expect.objectContaining({
+          kind: 'status-update',
+          status: expect.objectContaining({
+            state: 'failed',
+            message: expect.objectContaining({
+              parts: [{ kind: 'text', text: 'An error occurred.' }],
+            }),
+          }),
+        }),
+      );
+    });
+
+    describe('when handling submit_prompt', () => {
+      beforeEach(() => {
+        vi.mocked(performInit).mockReturnValue({
+          type: 'submit_prompt',
+          content: 'Create a new GEMINI.md file.',
+        } as CommandActionReturn);
+      });
+
+      it('writes the file and executes the agent', async () => {
+        await command.execute(context, []);
+
+        expect(fs.writeFileSync).toHaveBeenCalledWith(
+          path.join(mockWorkspacePath, 'GEMINI.md'),
+          '',
+          'utf8',
+        );
+        expect(mockExecute).toHaveBeenCalled();
+      });
+
+      it('passes autoExecute to the agent executor', async () => {
+        await command.execute(context, []);
+
+        expect(mockExecute).toHaveBeenCalledWith(
+          expect.objectContaining({
+            userMessage: expect.objectContaining({
+              parts: expect.arrayContaining([
+                expect.objectContaining({
+                  text: 'Create a new GEMINI.md file.',
+                }),
+              ]),
+              metadata: {
+                coderAgent: {
+                  kind: CoderAgentEvent.StateAgentSettingsEvent,
+                  workspacePath: mockWorkspacePath,
+                  autoExecute: true,
+                },
+              },
+            }),
+          }),
+          eventBus,
+        );
+      });
+    });
+  });
+});

packages/a2a-server/src/commands/init.ts

@@ -0,0 +1,169 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import { CoderAgentEvent, type AgentSettings } from '../types.js';
+import { performInit } from '@google/gemini-cli-core';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+import type { CoderAgentExecutor } from '../agent/executor.js';
+import type {
+  ExecutionEventBus,
+  RequestContext,
+  AgentExecutionEvent,
+} from '@a2a-js/sdk/server';
+import { v4 as uuidv4 } from 'uuid';
+import { logger } from '../utils/logger.js';
+
+export class InitCommand implements Command {
+  name = 'init';
+  description = 'Analyzes the project and creates a tailored GEMINI.md file';
+  requiresWorkspace = true;
+  streaming = true;
+
+  private handleMessageResult(
+    result: { content: string; messageType: 'info' | 'error' },
+    context: CommandContext,
+    eventBus: ExecutionEventBus,
+    taskId: string,
+    contextId: string,
+  ): CommandExecutionResponse {
+    const statusState = result.messageType === 'error' ? 'failed' : 'completed';
+    const eventType =
+      result.messageType === 'error'
+        ? CoderAgentEvent.StateChangeEvent
+        : CoderAgentEvent.TextContentEvent;
+
+    const event: AgentExecutionEvent = {
+      kind: 'status-update',
+      taskId,
+      contextId,
+      status: {
+        state: statusState,
+        message: {
+          kind: 'message',
+          role: 'agent',
+          parts: [{ kind: 'text', text: result.content }],
+          messageId: uuidv4(),
+          taskId,
+          contextId,
+        },
+        timestamp: new Date().toISOString(),
+      },
+      final: true,
+      metadata: {
+        coderAgent: { kind: eventType },
+        model: context.config.getModel(),
+      },
+    };
+
+    logger.info('[EventBus event]: ', event);
+    eventBus.publish(event);
+    return {
+      name: this.name,
+      data: result,
+    };
+  }
+
+  private async handleSubmitPromptResult(
+    result: { content: unknown },
+    context: CommandContext,
+    geminiMdPath: string,
+    eventBus: ExecutionEventBus,
+    taskId: string,
+    contextId: string,
+  ): Promise<CommandExecutionResponse> {
+    fs.writeFileSync(geminiMdPath, '', 'utf8');
+
+    if (!context.agentExecutor) {
+      throw new Error('Agent executor not found in context.');
+    }
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    const agentExecutor = context.agentExecutor as CoderAgentExecutor;
+
+    const agentSettings: AgentSettings = {
+      kind: CoderAgentEvent.StateAgentSettingsEvent,
+      workspacePath: process.env['CODER_AGENT_WORKSPACE_PATH']!,
+      autoExecute: true,
+    };
+
+    if (typeof result.content !== 'string') {
+      throw new Error('Init command content must be a string.');
+    }
+    const promptText = result.content;
+
+    const requestContext: RequestContext = {
+      userMessage: {
+        kind: 'message',
+        role: 'user',
+        parts: [{ kind: 'text', text: promptText }],
+        messageId: uuidv4(),
+        taskId,
+        contextId,
+        metadata: {
+          coderAgent: agentSettings,
+        },
+      },
+      taskId,
+      contextId,
+    };
+
+    // The executor will handle the entire agentic loop, including
+    // creating the task, streaming responses, and handling tools.
+    await agentExecutor.execute(requestContext, eventBus);
+    return {
+      name: this.name,
+      data: geminiMdPath,
+    };
+  }
+
+  async execute(
+    context: CommandContext,
+    _args: string[] = [],
+  ): Promise<CommandExecutionResponse> {
+    if (!context.eventBus) {
+      return {
+        name: this.name,
+        data: 'Use executeStream to get streaming results.',
+      };
+    }
+
+    const geminiMdPath = path.join(
+      process.env['CODER_AGENT_WORKSPACE_PATH']!,
+      'GEMINI.md',
+    );
+    const result = performInit(fs.existsSync(geminiMdPath));
+
+    const taskId = uuidv4();
+    const contextId = uuidv4();
+
+    switch (result.type) {
+      case 'message':
+        return this.handleMessageResult(
+          result,
+          context,
+          context.eventBus,
+          taskId,
+          contextId,
+        );
+      case 'submit_prompt':
+        return this.handleSubmitPromptResult(
+          result,
+          context,
+          geminiMdPath,
+          context.eventBus,
+          taskId,
+          contextId,
+        );
+      default:
+        throw new Error('Unknown result type from performInit');
+    }
+  }
+}

packages/a2a-server/src/commands/memory.test.ts

@@ -0,0 +1,114 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  listMemoryFiles,
+  refreshMemory,
+  showMemory,
+  type Config,
+} from '@google/gemini-cli-core';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import {
+  ListMemoryCommand,
+  MemoryCommand,
+  RefreshMemoryCommand,
+  ShowMemoryCommand,
+} from './memory.js';
+import type { CommandContext } from './types.js';
+
+// Mock the core functions
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    showMemory: vi.fn(),
+    refreshMemory: vi.fn(),
+    listMemoryFiles: vi.fn(),
+  };
+});
+
+const mockShowMemory = vi.mocked(showMemory);
+const mockRefreshMemory = vi.mocked(refreshMemory);
+const mockListMemoryFiles = vi.mocked(listMemoryFiles);
+
+describe('a2a-server memory commands', () => {
+  let mockContext: CommandContext;
+  let mockConfig: Config;
+
+  beforeEach(() => {
+    mockConfig = {} as unknown as Config;
+
+    mockContext = {
+      config: mockConfig,
+    };
+  });
+
+  describe('MemoryCommand', () => {
+    it('delegates to ShowMemoryCommand', async () => {
+      const command = new MemoryCommand();
+      mockShowMemory.mockReturnValue({
+        type: 'message',
+        messageType: 'info',
+        content: 'showing memory',
+      });
+      const response = await command.execute(mockContext, []);
+      expect(response.data).toBe('showing memory');
+      expect(mockShowMemory).toHaveBeenCalledWith(mockContext.config);
+    });
+  });
+
+  describe('ShowMemoryCommand', () => {
+    it('executes showMemory and returns the content', async () => {
+      const command = new ShowMemoryCommand();
+      mockShowMemory.mockReturnValue({
+        type: 'message',
+        messageType: 'info',
+        content: 'test memory content',
+      });
+
+      const response = await command.execute(mockContext, []);
+
+      expect(mockShowMemory).toHaveBeenCalledWith(mockContext.config);
+      expect(response.name).toBe('memory show');
+      expect(response.data).toBe('test memory content');
+    });
+  });
+
+  describe('RefreshMemoryCommand', () => {
+    it('executes refreshMemory and returns the content', async () => {
+      const command = new RefreshMemoryCommand();
+      mockRefreshMemory.mockResolvedValue({
+        type: 'message',
+        messageType: 'info',
+        content: 'memory refreshed',
+      });
+
+      const response = await command.execute(mockContext, []);
+
+      expect(mockRefreshMemory).toHaveBeenCalledWith(mockContext.config);
+      expect(response.name).toBe('memory refresh');
+      expect(response.data).toBe('memory refreshed');
+    });
+  });
+
+  describe('ListMemoryCommand', () => {
+    it('executes listMemoryFiles and returns the content', async () => {
+      const command = new ListMemoryCommand();
+      mockListMemoryFiles.mockReturnValue({
+        type: 'message',
+        messageType: 'info',
+        content: 'file1.md\nfile2.md',
+      });
+
+      const response = await command.execute(mockContext, []);
+
+      expect(mockListMemoryFiles).toHaveBeenCalledWith(mockContext.config);
+      expect(response.name).toBe('memory list');
+      expect(response.data).toBe('file1.md\nfile2.md');
+    });
+  });
+});

packages/a2a-server/src/commands/memory.ts

@@ -0,0 +1,74 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  listMemoryFiles,
+  refreshMemory,
+  showMemory,
+} from '@google/gemini-cli-core';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class MemoryCommand implements Command {
+  readonly name = 'memory';
+  readonly description = 'Manage memory.';
+  readonly subCommands = [
+    new ShowMemoryCommand(),
+    new RefreshMemoryCommand(),
+    new ListMemoryCommand(),
+  ];
+  readonly topLevel = true;
+  readonly requiresWorkspace = true;
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    return new ShowMemoryCommand().execute(context, _);
+  }
+}
+
+export class ShowMemoryCommand implements Command {
+  readonly name = 'memory show';
+  readonly description = 'Shows the current memory contents.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const result = showMemory(context.config);
+    return { name: this.name, data: result.content };
+  }
+}
+
+export class RefreshMemoryCommand implements Command {
+  readonly name = 'memory refresh';
+  readonly description = 'Refreshes the memory from the source.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const result = await refreshMemory(context.config);
+    return { name: this.name, data: result.content };
+  }
+}
+
+export class ListMemoryCommand implements Command {
+  readonly name = 'memory list';
+  readonly description = 'Lists the paths of the GEMINI.md files in use.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const result = listMemoryFiles(context.config);
+    return { name: this.name, data: result.content };
+  }
+}

packages/a2a-server/src/commands/restore.test.ts

@@ -0,0 +1,137 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { RestoreCommand, ListCheckpointsCommand } from './restore.js';
+import type { CommandContext } from './types.js';
+import type { Config } from '@google/gemini-cli-core';
+import { createMockConfig } from '../utils/testing_utils.js';
+
+beforeEach(() => {
+  vi.clearAllMocks();
+});
+
+const mockPerformRestore = vi.hoisted(() => vi.fn());
+const mockLoggerInfo = vi.hoisted(() => vi.fn());
+const mockGetCheckpointInfoList = vi.hoisted(() => vi.fn());
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...original,
+    performRestore: mockPerformRestore,
+    getCheckpointInfoList: mockGetCheckpointInfoList,
+  };
+});
+
+const mockFs = vi.hoisted(() => ({
+  readFile: vi.fn(),
+  readdir: vi.fn(),
+  mkdir: vi.fn(),
+}));
+
+vi.mock('node:fs/promises', () => mockFs);
+
+vi.mock('../utils/logger.js', () => ({
+  logger: {
+    info: mockLoggerInfo,
+  },
+}));
+
+describe('RestoreCommand', () => {
+  const mockConfig = {
+    config: createMockConfig() as Config,
+    git: {},
+  } as CommandContext;
+
+  it('should return error if no checkpoint name is provided', async () => {
+    const command = new RestoreCommand();
+    const result = await command.execute(mockConfig, []);
+    expect(result.data).toEqual({
+      type: 'message',
+      messageType: 'error',
+      content: 'Please provide a checkpoint name to restore.',
+    });
+  });
+
+  it('should restore a checkpoint when a valid file is provided', async () => {
+    const command = new RestoreCommand();
+    const toolCallData = {
+      toolCall: {
+        name: 'test-tool',
+        args: {},
+      },
+      history: [],
+      clientHistory: [],
+      commitHash: '123',
+    };
+    mockFs.readFile.mockResolvedValue(JSON.stringify(toolCallData));
+    const restoreContent = {
+      type: 'message',
+      messageType: 'info',
+      content: 'Restored',
+    };
+    mockPerformRestore.mockReturnValue(
+      (async function* () {
+        yield restoreContent;
+      })(),
+    );
+    const result = await command.execute(mockConfig, ['checkpoint1.json']);
+    expect(result.data).toEqual([restoreContent]);
+  });
+
+  it('should show "file not found" error for a non-existent checkpoint', async () => {
+    const command = new RestoreCommand();
+    const error = new Error('File not found');
+    (error as NodeJS.ErrnoException).code = 'ENOENT';
+    mockFs.readFile.mockRejectedValue(error);
+    const result = await command.execute(mockConfig, ['checkpoint2.json']);
+    expect(result.data).toEqual({
+      type: 'message',
+      messageType: 'error',
+      content: 'File not found: checkpoint2.json',
+    });
+  });
+
+  it('should handle invalid JSON in checkpoint file', async () => {
+    const command = new RestoreCommand();
+    mockFs.readFile.mockResolvedValue('invalid json');
+    const result = await command.execute(mockConfig, ['checkpoint1.json']);
+    expect((result.data as { content: string }).content).toContain(
+      'An unexpected error occurred during restore.',
+    );
+  });
+});
+
+describe('ListCheckpointsCommand', () => {
+  const mockConfig = {
+    config: createMockConfig() as Config,
+  } as CommandContext;
+
+  it('should list all available checkpoints', async () => {
+    const command = new ListCheckpointsCommand();
+    const checkpointInfo = [{ file: 'checkpoint1.json', description: 'Test' }];
+    mockFs.readdir.mockResolvedValue(['checkpoint1.json']);
+    mockFs.readFile.mockResolvedValue(
+      JSON.stringify({ toolCall: { name: 'Test', args: {} } }),
+    );
+    mockGetCheckpointInfoList.mockReturnValue(checkpointInfo);
+    const result = await command.execute(mockConfig);
+    expect((result.data as { content: string }).content).toEqual(
+      JSON.stringify(checkpointInfo),
+    );
+  });
+
+  it('should handle errors when listing checkpoints', async () => {
+    const command = new ListCheckpointsCommand();
+    mockFs.readdir.mockRejectedValue(new Error('Read error'));
+    const result = await command.execute(mockConfig);
+    expect((result.data as { content: string }).content).toContain(
+      'An unexpected error occurred while listing checkpoints.',
+    );
+  });
+});

packages/a2a-server/src/commands/restore.ts

@@ -0,0 +1,156 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  getCheckpointInfoList,
+  getToolCallDataSchema,
+  isNodeError,
+  performRestore,
+} from '@google/gemini-cli-core';
+import * as fs from 'node:fs/promises';
+import * as path from 'node:path';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class RestoreCommand implements Command {
+  readonly name = 'restore';
+  readonly description =
+    'Restore to a previous checkpoint, or list available checkpoints to restore. This will reset the conversation and file history to the state it was in when the checkpoint was created';
+  readonly topLevel = true;
+  readonly requiresWorkspace = true;
+  readonly subCommands = [new ListCheckpointsCommand()];
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const { config, git: gitService } = context;
+    const argsStr = args.join(' ');
+
+    try {
+      if (!argsStr) {
+        return {
+          name: this.name,
+          data: {
+            type: 'message',
+            messageType: 'error',
+            content: 'Please provide a checkpoint name to restore.',
+          },
+        };
+      }
+
+      const selectedFile = argsStr.endsWith('.json')
+        ? argsStr
+        : `${argsStr}.json`;
+
+      const checkpointDir = config.storage.getProjectTempCheckpointsDir();
+      const filePath = path.join(checkpointDir, selectedFile);
+
+      let data: string;
+      try {
+        data = await fs.readFile(filePath, 'utf-8');
+      } catch (error) {
+        if (isNodeError(error) && error.code === 'ENOENT') {
+          return {
+            name: this.name,
+            data: {
+              type: 'message',
+              messageType: 'error',
+              content: `File not found: ${selectedFile}`,
+            },
+          };
+        }
+        throw error;
+      }
+
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const toolCallData = JSON.parse(data);
+      const ToolCallDataSchema = getToolCallDataSchema();
+      const parseResult = ToolCallDataSchema.safeParse(toolCallData);
+
+      if (!parseResult.success) {
+        return {
+          name: this.name,
+          data: {
+            type: 'message',
+            messageType: 'error',
+            content: 'Checkpoint file is invalid or corrupted.',
+          },
+        };
+      }
+
+      const restoreResultGenerator = performRestore(
+        parseResult.data,
+        gitService,
+      );
+      const restoreResult = [];
+      for await (const result of restoreResultGenerator) {
+        restoreResult.push(result);
+      }
+
+      return {
+        name: this.name,
+        data: restoreResult,
+      };
+    } catch {
+      return {
+        name: this.name,
+        data: {
+          type: 'message',
+          messageType: 'error',
+          content: 'An unexpected error occurred during restore.',
+        },
+      };
+    }
+  }
+}
+
+export class ListCheckpointsCommand implements Command {
+  readonly name = 'restore list';
+  readonly description = 'Lists all available checkpoints.';
+  readonly topLevel = false;
+
+  async execute(context: CommandContext): Promise<CommandExecutionResponse> {
+    const { config } = context;
+
+    try {
+      const checkpointDir = config.storage.getProjectTempCheckpointsDir();
+      await fs.mkdir(checkpointDir, { recursive: true });
+      const files = await fs.readdir(checkpointDir);
+      const jsonFiles = files.filter((file) => file.endsWith('.json'));
+
+      const checkpointFiles = new Map<string, string>();
+      for (const file of jsonFiles) {
+        const filePath = path.join(checkpointDir, file);
+        const data = await fs.readFile(filePath, 'utf-8');
+        checkpointFiles.set(file, data);
+      }
+
+      const checkpointInfoList = getCheckpointInfoList(checkpointFiles);
+
+      return {
+        name: this.name,
+        data: {
+          type: 'message',
+          messageType: 'info',
+          content: JSON.stringify(checkpointInfoList),
+        },
+      };
+    } catch {
+      return {
+        name: this.name,
+        data: {
+          type: 'message',
+          messageType: 'error',
+          content: 'An unexpected error occurred while listing checkpoints.',
+        },
+      };
+    }
+  }
+}

packages/a2a-server/src/commands/types.ts

@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { ExecutionEventBus, AgentExecutor } from '@a2a-js/sdk/server';
+import type { Config, GitService } from '@google/gemini-cli-core';
+
+export interface CommandContext {
+  config: Config;
+  git?: GitService;
+  agentExecutor?: AgentExecutor;
+  eventBus?: ExecutionEventBus;
+}
+
+export interface CommandArgument {
+  readonly name: string;
+  readonly description: string;
+  readonly isRequired?: boolean;
+}
+
+export interface Command {
+  readonly name: string;
+  readonly description: string;
+  readonly arguments?: CommandArgument[];
+  readonly subCommands?: Command[];
+  readonly topLevel?: boolean;
+  readonly requiresWorkspace?: boolean;
+  readonly streaming?: boolean;
+
+  execute(
+    config: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse>;
+}
+
+export interface CommandExecutionResponse {
+  readonly name: string;
+  readonly data: unknown;
+}

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

@@ -0,0 +1,575 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import * as path from 'node:path';
+import { loadConfig } from './config.js';
+import type { Settings } from './settings.js';
+import {
+  type ExtensionLoader,
+  getCodeAssistServer,
+  Config,
+  ExperimentFlags,
+  fetchAdminControlsOnce,
+  type FetchAdminControlsResponse,
+  AuthType,
+  isHeadlessMode,
+  FatalAuthenticationError,
+  PolicyDecision,
+  ApprovalMode,
+  PRIORITY_YOLO_ALLOW_ALL,
+  createPolicyEngineConfig,
+} from '@google/gemini-cli-core';
+import type { AgentSettings } from '../types.js';
+
+// Mock dependencies
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    PRIORITY_YOLO_ALLOW_ALL: 998,
+    Config: vi.fn().mockImplementation((params) => {
+      const mockConfig = {
+        ...params,
+        initialize: vi.fn(),
+        waitForMcpInit: vi.fn(),
+        refreshAuth: vi.fn(),
+        getExperiments: vi.fn().mockReturnValue({
+          flags: {
+            [actual.ExperimentFlags.ENABLE_ADMIN_CONTROLS]: {
+              boolValue: false,
+            },
+          },
+        }),
+        getRemoteAdminSettings: vi.fn(),
+        setRemoteAdminSettings: vi.fn(),
+      };
+      return mockConfig;
+    }),
+    startupProfiler: {
+      flush: vi.fn(),
+    },
+    isHeadlessMode: vi.fn().mockReturnValue(false),
+    getCodeAssistServer: vi.fn(),
+    fetchAdminControlsOnce: vi.fn(),
+    createPolicyEngineConfig: vi
+      .fn()
+      .mockImplementation(
+        (_settings, mode, _defaultPoliciesDir, _interactive) => ({
+          rules:
+            mode === actual.ApprovalMode.YOLO
+              ? [
+                  {
+                    toolName: '*',
+                    decision: actual.PolicyDecision.ALLOW,
+                    priority: actual.PRIORITY_YOLO_ALLOW_ALL,
+                    modes: [actual.ApprovalMode.YOLO],
+                    allowRedirection: true,
+                  },
+                ]
+              : [
+                  {
+                    toolName: 'read_file',
+                    decision: actual.PolicyDecision.ALLOW,
+                    priority: 1.05,
+                    source: 'Default: read-only.toml',
+                  },
+                ],
+          checkers: [],
+        }),
+      ),
+    coreEvents: {
+      emitAdminSettingsChanged: vi.fn(),
+    },
+  };
+});
+
+vi.mock('../utils/logger.js', () => ({
+  logger: {
+    info: vi.fn(),
+    warn: vi.fn(),
+    error: vi.fn(),
+  },
+}));
+
+describe('loadConfig', () => {
+  const mockSettings = {} as Settings;
+  const mockExtensionLoader = {} as ExtensionLoader;
+  const taskId = 'test-task-id';
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.stubEnv('GEMINI_API_KEY', 'test-key');
+  });
+
+  afterEach(() => {
+    vi.unstubAllEnvs();
+  });
+
+  describe('admin settings overrides', () => {
+    it('should not fetch admin controls if experiment is disabled', async () => {
+      await loadConfig(mockSettings, mockExtensionLoader, taskId);
+      expect(fetchAdminControlsOnce).not.toHaveBeenCalled();
+    });
+
+    it('should pass clientName as a2a-server to Config', async () => {
+      await loadConfig(mockSettings, mockExtensionLoader, taskId);
+      expect(Config).toHaveBeenCalledWith(
+        expect.objectContaining({
+          clientName: 'a2a-server',
+        }),
+      );
+    });
+
+    describe('when admin controls experiment is enabled', () => {
+      beforeEach(() => {
+        // We need to cast to any here to modify the mock implementation
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        (Config as any).mockImplementation((params: unknown) => {
+          const mockConfig = {
+            ...(params as object),
+            initialize: vi.fn(),
+            waitForMcpInit: vi.fn(),
+            refreshAuth: vi.fn(),
+            getExperiments: vi.fn().mockReturnValue({
+              flags: {
+                [ExperimentFlags.ENABLE_ADMIN_CONTROLS]: {
+                  boolValue: true,
+                },
+              },
+            }),
+            getRemoteAdminSettings: vi.fn().mockReturnValue({}),
+            setRemoteAdminSettings: vi.fn(),
+          };
+          return mockConfig;
+        });
+      });
+
+      it('should fetch admin controls and apply them', async () => {
+        const mockAdminSettings: FetchAdminControlsResponse = {
+          mcpSetting: {
+            mcpEnabled: false,
+          },
+          cliFeatureSetting: {
+            extensionsSetting: {
+              extensionsEnabled: false,
+            },
+          },
+          strictModeDisabled: false,
+        };
+        vi.mocked(fetchAdminControlsOnce).mockResolvedValue(mockAdminSettings);
+
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+
+        expect(Config).toHaveBeenLastCalledWith(
+          expect.objectContaining({
+            disableYoloMode: !mockAdminSettings.strictModeDisabled,
+            mcpEnabled: mockAdminSettings.mcpSetting?.mcpEnabled,
+            extensionsEnabled:
+              mockAdminSettings.cliFeatureSetting?.extensionsSetting
+                ?.extensionsEnabled,
+          }),
+        );
+      });
+
+      it('should treat unset admin settings as false when admin settings are passed', async () => {
+        const mockAdminSettings: FetchAdminControlsResponse = {
+          mcpSetting: {
+            mcpEnabled: true,
+          },
+        };
+        vi.mocked(fetchAdminControlsOnce).mockResolvedValue(mockAdminSettings);
+
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+
+        expect(Config).toHaveBeenLastCalledWith(
+          expect.objectContaining({
+            disableYoloMode: !false,
+            mcpEnabled: mockAdminSettings.mcpSetting?.mcpEnabled,
+            extensionsEnabled: undefined,
+          }),
+        );
+      });
+
+      it('should not pass default unset admin settings when no admin settings are present', async () => {
+        const mockAdminSettings: FetchAdminControlsResponse = {};
+        vi.mocked(fetchAdminControlsOnce).mockResolvedValue(mockAdminSettings);
+
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+
+        expect(Config).toHaveBeenLastCalledWith(expect.objectContaining({}));
+      });
+
+      it('should fetch admin controls using the code assist server when available', async () => {
+        const mockAdminSettings: FetchAdminControlsResponse = {
+          mcpSetting: {
+            mcpEnabled: true,
+          },
+          strictModeDisabled: true,
+        };
+        const mockCodeAssistServer = { projectId: 'test-project' };
+        vi.mocked(getCodeAssistServer).mockReturnValue(
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          mockCodeAssistServer as any,
+        );
+        vi.mocked(fetchAdminControlsOnce).mockResolvedValue(mockAdminSettings);
+
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+
+        expect(fetchAdminControlsOnce).toHaveBeenCalledWith(
+          mockCodeAssistServer,
+          true,
+        );
+        expect(Config).toHaveBeenLastCalledWith(
+          expect.objectContaining({
+            disableYoloMode: !mockAdminSettings.strictModeDisabled,
+            mcpEnabled: mockAdminSettings.mcpSetting?.mcpEnabled,
+            extensionsEnabled: undefined,
+          }),
+        );
+      });
+    });
+  });
+
+  it('should set customIgnoreFilePaths when CUSTOM_IGNORE_FILE_PATHS env var is present', async () => {
+    const testPath = '/tmp/ignore';
+    vi.stubEnv('CUSTOM_IGNORE_FILE_PATHS', testPath);
+    const config = await loadConfig(mockSettings, mockExtensionLoader, taskId);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    expect((config as any).fileFiltering.customIgnoreFilePaths).toEqual([
+      testPath,
+    ]);
+  });
+
+  it('should set customIgnoreFilePaths when settings.fileFiltering.customIgnoreFilePaths is present', async () => {
+    const testPath = '/settings/ignore';
+    const settings: Settings = {
+      fileFiltering: {
+        customIgnoreFilePaths: [testPath],
+      },
+    };
+    const config = await loadConfig(settings, mockExtensionLoader, taskId);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    expect((config as any).fileFiltering.customIgnoreFilePaths).toEqual([
+      testPath,
+    ]);
+  });
+
+  it('should merge customIgnoreFilePaths from settings and env var', async () => {
+    const envPath = '/env/ignore';
+    const settingsPath = '/settings/ignore';
+    vi.stubEnv('CUSTOM_IGNORE_FILE_PATHS', envPath);
+    const settings: Settings = {
+      fileFiltering: {
+        customIgnoreFilePaths: [settingsPath],
+      },
+    };
+    const config = await loadConfig(settings, mockExtensionLoader, taskId);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    expect((config as any).fileFiltering.customIgnoreFilePaths).toEqual([
+      settingsPath,
+      envPath,
+    ]);
+  });
+
+  it('should split CUSTOM_IGNORE_FILE_PATHS using system delimiter', async () => {
+    const paths = ['/path/one', '/path/two'];
+    vi.stubEnv('CUSTOM_IGNORE_FILE_PATHS', paths.join(path.delimiter));
+    const config = await loadConfig(mockSettings, mockExtensionLoader, taskId);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    expect((config as any).fileFiltering.customIgnoreFilePaths).toEqual(paths);
+  });
+
+  it('should have empty customIgnoreFilePaths when both are missing', async () => {
+    const config = await loadConfig(mockSettings, mockExtensionLoader, taskId);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    expect((config as any).fileFiltering.customIgnoreFilePaths).toEqual([]);
+  });
+
+  describe('policy engine configuration', () => {
+    it('should map tool settings into policySettings', async () => {
+      const settings: Settings = {
+        tools: {
+          allowed: ['v2-allowed'],
+          exclude: ['v2-exclude'],
+          core: ['v2-core'],
+        },
+        mcpServers: {
+          test: { command: 'test', args: [] },
+        },
+        policyPaths: ['/path/to/policy'],
+        adminPolicyPaths: ['/path/to/admin/policy'],
+      };
+
+      await loadConfig(settings, mockExtensionLoader, taskId);
+
+      expect(createPolicyEngineConfig).toHaveBeenCalledWith(
+        expect.objectContaining({
+          tools: {
+            core: ['v2-core'],
+            exclude: ['v2-exclude'],
+            allowed: ['v2-allowed'],
+          },
+          mcpServers: settings.mcpServers,
+          policyPaths: settings.policyPaths,
+          adminPolicyPaths: settings.adminPolicyPaths,
+        }),
+        ApprovalMode.DEFAULT,
+        undefined,
+        true,
+      );
+    });
+  });
+
+  describe('tool configuration', () => {
+    it('should pass V2 tools.allowed to Config properly', async () => {
+      const settings: Settings = {
+        tools: {
+          allowed: ['shell', 'fetch'],
+        },
+      };
+      await loadConfig(settings, mockExtensionLoader, taskId);
+      expect(Config).toHaveBeenCalledWith(
+        expect.objectContaining({
+          allowedTools: ['shell', 'fetch'],
+        }),
+      );
+    });
+
+    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 always set interactive true', async () => {
+        vi.mocked(isHeadlessMode).mockReturnValue(true);
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+        expect(Config).toHaveBeenCalledWith(
+          expect.objectContaining({
+            interactive: true,
+          }),
+        );
+
+        vi.mocked(isHeadlessMode).mockReturnValue(false);
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+        expect(Config).toHaveBeenCalledWith(
+          expect.objectContaining({
+            interactive: true,
+          }),
+        );
+      });
+
+      it('should set enableInteractiveShell based on headless mode', async () => {
+        vi.mocked(isHeadlessMode).mockReturnValue(false);
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+        expect(Config).toHaveBeenCalledWith(
+          expect.objectContaining({
+            enableInteractiveShell: true,
+          }),
+        );
+
+        vi.mocked(isHeadlessMode).mockReturnValue(true);
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+        expect(Config).toHaveBeenCalledWith(
+          expect.objectContaining({
+            enableInteractiveShell: false,
+          }),
+        );
+      });
+    });
+
+    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 load default 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: expect.arrayContaining([
+                expect.objectContaining({
+                  toolName: 'read_file',
+                  decision: PolicyDecision.ALLOW,
+                }),
+              ]),
+            }),
+          }),
+        );
+      });
+    });
+
+    describe('authentication logic', () => {
+      const setupConfigMock = (refreshAuthMock: ReturnType<typeof vi.fn>) => {
+        vi.mocked(Config).mockImplementation(
+          (params: unknown) =>
+            ({
+              ...(params as object),
+              initialize: vi.fn(),
+              waitForMcpInit: vi.fn(),
+              refreshAuth: refreshAuthMock,
+              getExperiments: vi.fn().mockReturnValue({ flags: {} }),
+              getRemoteAdminSettings: vi.fn(),
+              setRemoteAdminSettings: vi.fn(),
+            }) as unknown as Config,
+        );
+      };
+
+      beforeEach(() => {
+        vi.stubEnv('USE_CCPA', 'true');
+        vi.stubEnv('GEMINI_API_KEY', '');
+      });
+
+      afterEach(() => {
+        vi.unstubAllEnvs();
+      });
+
+      it('should attempt COMPUTE_ADC by default and bypass LOGIN_WITH_GOOGLE if successful', async () => {
+        const refreshAuthMock = vi.fn().mockResolvedValue(undefined);
+        setupConfigMock(refreshAuthMock);
+
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+
+        expect(refreshAuthMock).toHaveBeenCalledWith(AuthType.COMPUTE_ADC);
+        expect(refreshAuthMock).not.toHaveBeenCalledWith(
+          AuthType.LOGIN_WITH_GOOGLE,
+        );
+      });
+
+      it('should fallback to LOGIN_WITH_GOOGLE if COMPUTE_ADC fails and interactive mode is available', async () => {
+        vi.mocked(isHeadlessMode).mockReturnValue(false);
+        const refreshAuthMock = vi.fn().mockImplementation((authType) => {
+          if (authType === AuthType.COMPUTE_ADC) {
+            return Promise.reject(new Error('ADC failed'));
+          }
+          return Promise.resolve();
+        });
+        setupConfigMock(refreshAuthMock);
+
+        await loadConfig(mockSettings, mockExtensionLoader, taskId);
+
+        expect(refreshAuthMock).toHaveBeenCalledWith(AuthType.COMPUTE_ADC);
+        expect(refreshAuthMock).toHaveBeenCalledWith(
+          AuthType.LOGIN_WITH_GOOGLE,
+        );
+      });
+
+      it('should throw FatalAuthenticationError in headless mode if COMPUTE_ADC fails', async () => {
+        vi.mocked(isHeadlessMode).mockReturnValue(true);
+
+        const refreshAuthMock = vi.fn().mockImplementation((authType) => {
+          if (authType === AuthType.COMPUTE_ADC) {
+            return Promise.reject(new Error('ADC not found'));
+          }
+          return Promise.resolve();
+        });
+        setupConfigMock(refreshAuthMock);
+
+        await expect(
+          loadConfig(mockSettings, mockExtensionLoader, taskId),
+        ).rejects.toThrow(
+          'COMPUTE_ADC failed: ADC not found. (LOGIN_WITH_GOOGLE fallback skipped due to headless mode. Run in an interactive terminal to use OAuth.)',
+        );
+
+        expect(refreshAuthMock).toHaveBeenCalledWith(AuthType.COMPUTE_ADC);
+        expect(refreshAuthMock).not.toHaveBeenCalledWith(
+          AuthType.LOGIN_WITH_GOOGLE,
+        );
+      });
+
+      it('should include both original and fallback error when LOGIN_WITH_GOOGLE fallback fails', async () => {
+        vi.mocked(isHeadlessMode).mockReturnValue(false);
+
+        const refreshAuthMock = vi.fn().mockImplementation((authType) => {
+          if (authType === AuthType.COMPUTE_ADC) {
+            throw new Error('ADC failed');
+          }
+          if (authType === AuthType.LOGIN_WITH_GOOGLE) {
+            throw new FatalAuthenticationError('OAuth failed');
+          }
+          return Promise.resolve();
+        });
+        setupConfigMock(refreshAuthMock);
+
+        await expect(
+          loadConfig(mockSettings, mockExtensionLoader, taskId),
+        ).rejects.toThrow(
+          'OAuth failed. The initial COMPUTE_ADC attempt also failed: ADC failed',
+        );
+      });
+    });
+  });
+});
+
+describe('setIsTrusted', () => {
+  beforeEach(() => {
+    vi.resetModules();
+  });
+
+  afterEach(() => {
+    vi.unstubAllEnvs();
+  });
+
+  it('should return true when GEMINI_FOLDER_TRUST env var is true', async () => {
+    vi.stubEnv('GEMINI_FOLDER_TRUST', 'true');
+    const { setIsTrusted } = await import('./config.js');
+    expect(setIsTrusted(undefined)).toBe(true);
+    expect(setIsTrusted({ isTrusted: false } as AgentSettings)).toBe(true);
+  });
+
+  it('should return false when GEMINI_FOLDER_TRUST env var is false', async () => {
+    vi.stubEnv('GEMINI_FOLDER_TRUST', 'false');
+    const { setIsTrusted } = await import('./config.js');
+    expect(setIsTrusted(undefined)).toBe(false);
+    expect(setIsTrusted({ isTrusted: true } as AgentSettings)).toBe(false);
+  });
+
+  it('should fallback to agentSettings.isTrusted if env var is undefined', async () => {
+    const { setIsTrusted } = await import('./config.js');
+    expect(setIsTrusted({ isTrusted: true } as AgentSettings)).toBe(true);
+    expect(setIsTrusted({ isTrusted: false } as AgentSettings)).toBe(false);
+    expect(setIsTrusted(undefined)).toBe(false);
+  });
+});

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

@@ -0,0 +1,318 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import * as dotenv from 'dotenv';
+
+import {
+  AuthType,
+  Config,
+  ApprovalMode,
+  GEMINI_DIR,
+  DEFAULT_GEMINI_EMBEDDING_MODEL,
+  startupProfiler,
+  PREVIEW_GEMINI_MODEL,
+  homedir,
+  GitService,
+  fetchAdminControlsOnce,
+  getCodeAssistServer,
+  ExperimentFlags,
+  isHeadlessMode,
+  FatalAuthenticationError,
+  createPolicyEngineConfig,
+  type PolicySettings,
+  type TelemetryTarget,
+  type ConfigParameters,
+  type ExtensionLoader,
+} from '@google/gemini-cli-core';
+
+import { logger } from '../utils/logger.js';
+import type { Settings } from './settings.js';
+import { type AgentSettings, CoderAgentEvent } from '../types.js';
+
+const INITIAL_FOLDER_TRUST = process.env['GEMINI_FOLDER_TRUST'];
+
+export async function loadConfig(
+  settings: Settings,
+  extensionLoader: ExtensionLoader,
+  taskId: string,
+  trusted: boolean = false,
+): Promise<Config> {
+  const workspaceDir = process.cwd();
+
+  const folderTrust =
+    settings.folderTrust === true ||
+    process.env['GEMINI_FOLDER_TRUST'] === 'true';
+
+  let checkpointing = process.env['CHECKPOINTING']
+    ? process.env['CHECKPOINTING'] === 'true'
+    : settings.checkpointing?.enabled;
+
+  if (checkpointing) {
+    if (!(await GitService.verifyGitAvailability())) {
+      logger.warn(
+        '[Config] Checkpointing is enabled but git is not installed. Disabling checkpointing.',
+      );
+      checkpointing = false;
+    }
+  }
+
+  const approvalMode =
+    process.env['GEMINI_YOLO_MODE'] === 'true'
+      ? ApprovalMode.YOLO
+      : ApprovalMode.DEFAULT;
+
+  const policySettings: PolicySettings = {
+    mcpServers: settings.mcpServers,
+    tools: {
+      core: settings.tools?.core,
+      exclude: settings.tools?.exclude,
+      allowed: settings.tools?.allowed,
+    },
+    policyPaths: settings.policyPaths,
+    adminPolicyPaths: settings.adminPolicyPaths,
+  };
+
+  const policyEngineConfig = await createPolicyEngineConfig(
+    policySettings,
+    approvalMode,
+    undefined,
+    true,
+  );
+
+  const configParams: ConfigParameters = {
+    sessionId: taskId,
+    clientName: 'a2a-server',
+    model: PREVIEW_GEMINI_MODEL,
+    embeddingModel: DEFAULT_GEMINI_EMBEDDING_MODEL,
+    sandbox: undefined, // Sandbox might not be relevant for a server-side agent
+    targetDir: workspaceDir, // Or a specific directory the agent operates on
+    debugMode: process.env['DEBUG'] === 'true' || false,
+    question: '', // Not used in server mode directly like CLI
+
+    coreTools: settings.tools?.core || undefined,
+    excludeTools: settings.tools?.exclude || undefined,
+    allowedTools: settings.tools?.allowed || undefined,
+    showMemoryUsage: settings.showMemoryUsage || false,
+    approvalMode,
+    policyEngineConfig,
+    mcpServers: settings.mcpServers,
+    cwd: workspaceDir,
+    telemetry: {
+      enabled: settings.telemetry?.enabled,
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      target: settings.telemetry?.target as TelemetryTarget,
+      otlpEndpoint:
+        process.env['OTEL_EXPORTER_OTLP_ENDPOINT'] ??
+        settings.telemetry?.otlpEndpoint,
+      logPrompts: settings.telemetry?.logPrompts,
+    },
+    // Git-aware file filtering settings
+    fileFiltering: {
+      respectGitIgnore: settings.fileFiltering?.respectGitIgnore,
+      respectGeminiIgnore: settings.fileFiltering?.respectGeminiIgnore,
+      enableRecursiveFileSearch:
+        settings.fileFiltering?.enableRecursiveFileSearch,
+      customIgnoreFilePaths: [
+        ...(settings.fileFiltering?.customIgnoreFilePaths || []),
+        ...(process.env['CUSTOM_IGNORE_FILE_PATHS']
+          ? process.env['CUSTOM_IGNORE_FILE_PATHS'].split(path.delimiter)
+          : []),
+      ],
+    },
+    ideMode: false,
+    folderTrust,
+    trustedFolder: trusted,
+    extensionLoader,
+    checkpointing,
+    interactive: true,
+    enableInteractiveShell: !isHeadlessMode(),
+    ptyInfo: 'auto',
+    enableAgents: settings.experimental?.enableAgents ?? true,
+  };
+
+  // Set an initial config to use to get a code assist server.
+  // This is needed to fetch admin controls.
+  const initialConfig = new Config({
+    ...configParams,
+  });
+
+  const codeAssistServer = getCodeAssistServer(initialConfig);
+
+  const adminControlsEnabled =
+    initialConfig.getExperiments()?.flags[ExperimentFlags.ENABLE_ADMIN_CONTROLS]
+      ?.boolValue ?? false;
+
+  // Initialize final config parameters to the previous parameters.
+  // If no admin controls are needed, these will be used as-is for the final
+  // config.
+  const finalConfigParams = { ...configParams };
+  if (adminControlsEnabled) {
+    const adminSettings = await fetchAdminControlsOnce(
+      codeAssistServer,
+      adminControlsEnabled,
+    );
+
+    // Admin settings are able to be undefined if unset, but if any are present,
+    // we should initialize them all.
+    // If any are present, undefined settings should be treated as if they were
+    // set to false.
+    // If NONE are present, disregard admin settings entirely, and pass the
+    // final config as is.
+    if (Object.keys(adminSettings).length !== 0) {
+      finalConfigParams.disableYoloMode = !adminSettings.strictModeDisabled;
+      finalConfigParams.mcpEnabled = adminSettings.mcpSetting?.mcpEnabled;
+      finalConfigParams.extensionsEnabled =
+        adminSettings.cliFeatureSetting?.extensionsSetting?.extensionsEnabled;
+    }
+  }
+
+  const config = new Config(finalConfigParams);
+
+  // Needed to initialize ToolRegistry, and git checkpointing if enabled
+  await config.initialize();
+
+  await config.waitForMcpInit();
+  startupProfiler.flush(config);
+
+  await refreshAuthentication(config, 'Config');
+
+  return config;
+}
+
+export function setIsTrusted(
+  agentSettings: AgentSettings | undefined,
+): boolean {
+  if (INITIAL_FOLDER_TRUST !== undefined) {
+    return INITIAL_FOLDER_TRUST === 'true';
+  }
+  return !!agentSettings?.isTrusted;
+}
+
+export function setTargetDir(agentSettings: AgentSettings | undefined): string {
+  const originalCWD = process.cwd();
+  const targetDir =
+    process.env['CODER_AGENT_WORKSPACE_PATH'] ??
+    (agentSettings?.kind === CoderAgentEvent.StateAgentSettingsEvent
+      ? agentSettings.workspacePath
+      : undefined);
+
+  if (!targetDir) {
+    return originalCWD;
+  }
+
+  logger.info(
+    `[CoderAgentExecutor] Overriding workspace path to: ${targetDir}`,
+  );
+
+  try {
+    const resolvedPath = path.resolve(targetDir);
+    process.chdir(resolvedPath);
+    return resolvedPath;
+  } catch (e) {
+    logger.error(
+      `[CoderAgentExecutor] Error resolving workspace path: ${e}, returning original os.cwd()`,
+    );
+    return originalCWD;
+  }
+}
+
+export function loadEnvironment(): void {
+  const envFilePath = findEnvFile(process.cwd());
+  if (envFilePath) {
+    dotenv.config({ path: envFilePath, override: true });
+  }
+}
+
+function findEnvFile(startDir: string): string | null {
+  let currentDir = path.resolve(startDir);
+  while (true) {
+    // prefer gemini-specific .env under GEMINI_DIR
+    const geminiEnvPath = path.join(currentDir, GEMINI_DIR, '.env');
+    if (fs.existsSync(geminiEnvPath)) {
+      return geminiEnvPath;
+    }
+    const envPath = path.join(currentDir, '.env');
+    if (fs.existsSync(envPath)) {
+      return envPath;
+    }
+    const parentDir = path.dirname(currentDir);
+    if (parentDir === currentDir || !parentDir) {
+      // check .env under home as fallback, again preferring gemini-specific .env
+      const homeGeminiEnvPath = path.join(process.cwd(), GEMINI_DIR, '.env');
+      if (fs.existsSync(homeGeminiEnvPath)) {
+        return homeGeminiEnvPath;
+      }
+      const homeEnvPath = path.join(homedir(), '.env');
+      if (fs.existsSync(homeEnvPath)) {
+        return homeEnvPath;
+      }
+      return null;
+    }
+    currentDir = parentDir;
+  }
+}
+
+async function refreshAuthentication(
+  config: Config,
+  logPrefix: string,
+): Promise<void> {
+  if (process.env['USE_CCPA']) {
+    logger.info(`[${logPrefix}] Using CCPA Auth:`);
+
+    logger.info(`[${logPrefix}] Attempting COMPUTE_ADC first.`);
+    try {
+      await config.refreshAuth(AuthType.COMPUTE_ADC);
+      logger.info(`[${logPrefix}] COMPUTE_ADC successful.`);
+    } catch (adcError) {
+      const adcMessage =
+        adcError instanceof Error ? adcError.message : String(adcError);
+      logger.info(
+        `[${logPrefix}] COMPUTE_ADC failed or not available: ${adcMessage}`,
+      );
+
+      const useComputeAdc =
+        process.env['GEMINI_CLI_USE_COMPUTE_ADC'] === 'true';
+      const isHeadless = isHeadlessMode();
+
+      if (isHeadless || useComputeAdc) {
+        const reason = isHeadless
+          ? 'headless mode'
+          : 'GEMINI_CLI_USE_COMPUTE_ADC=true';
+        throw new FatalAuthenticationError(
+          `COMPUTE_ADC failed: ${adcMessage}. (LOGIN_WITH_GOOGLE fallback skipped due to ${reason}. Run in an interactive terminal to use OAuth.)`,
+        );
+      }
+
+      logger.info(
+        `[${logPrefix}] COMPUTE_ADC failed, falling back to LOGIN_WITH_GOOGLE.`,
+      );
+      try {
+        await config.refreshAuth(AuthType.LOGIN_WITH_GOOGLE);
+      } catch (e) {
+        if (e instanceof FatalAuthenticationError) {
+          const originalMessage = e instanceof Error ? e.message : String(e);
+          throw new FatalAuthenticationError(
+            `${originalMessage}. The initial COMPUTE_ADC attempt also failed: ${adcMessage}`,
+          );
+        }
+        throw e;
+      }
+    }
+
+    logger.info(
+      `[${logPrefix}] GOOGLE_CLOUD_PROJECT: ${process.env['GOOGLE_CLOUD_PROJECT']}`,
+    );
+  } else if (process.env['GEMINI_API_KEY']) {
+    logger.info(`[${logPrefix}] Using Gemini API Key`);
+    await config.refreshAuth(AuthType.USE_GEMINI);
+  } else {
+    const errorMessage = `[${logPrefix}] Unable to set GeneratorConfig. Please provide a GEMINI_API_KEY or set USE_CCPA.`;
+    logger.error(errorMessage);
+    throw new Error(errorMessage);
+  }
+}

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

@@ -0,0 +1,154 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// Copied exactly from packages/cli/src/config/extension.ts, last PR #1026
+
+import {
+  GEMINI_DIR,
+  type MCPServerConfig,
+  type ExtensionInstallMetadata,
+  type GeminiCLIExtension,
+  homedir,
+} from '@google/gemini-cli-core';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import { logger } from '../utils/logger.js';
+
+export const EXTENSIONS_DIRECTORY_NAME = path.join(GEMINI_DIR, 'extensions');
+export const EXTENSIONS_CONFIG_FILENAME = 'gemini-extension.json';
+export const INSTALL_METADATA_FILENAME = '.gemini-extension-install.json';
+
+/**
+ * Extension definition as written to disk in gemini-extension.json files.
+ * This should *not* be referenced outside of the logic for reading files.
+ * If information is required for manipulating extensions (load, unload, update)
+ * outside of the loading process that data needs to be stored on the
+ * GeminiCLIExtension class defined in Core.
+ */
+interface ExtensionConfig {
+  name: string;
+  version: string;
+  mcpServers?: Record<string, MCPServerConfig>;
+  contextFileName?: string | string[];
+  excludeTools?: string[];
+}
+
+export function loadExtensions(workspaceDir: string): GeminiCLIExtension[] {
+  const allExtensions = [
+    ...loadExtensionsFromDir(workspaceDir),
+    ...loadExtensionsFromDir(homedir()),
+  ];
+
+  const uniqueExtensions: GeminiCLIExtension[] = [];
+  const seenNames = new Set<string>();
+  for (const extension of allExtensions) {
+    if (!seenNames.has(extension.name)) {
+      logger.info(
+        `Loading extension: ${extension.name} (version: ${extension.version})`,
+      );
+      uniqueExtensions.push(extension);
+      seenNames.add(extension.name);
+    }
+  }
+
+  return uniqueExtensions;
+}
+
+function loadExtensionsFromDir(dir: string): GeminiCLIExtension[] {
+  const extensionsDir = path.join(dir, EXTENSIONS_DIRECTORY_NAME);
+  if (!fs.existsSync(extensionsDir)) {
+    return [];
+  }
+
+  const extensions: GeminiCLIExtension[] = [];
+  for (const subdir of fs.readdirSync(extensionsDir)) {
+    const extensionDir = path.join(extensionsDir, subdir);
+
+    const extension = loadExtension(extensionDir);
+    if (extension != null) {
+      extensions.push(extension);
+    }
+  }
+  return extensions;
+}
+
+function loadExtension(extensionDir: string): GeminiCLIExtension | null {
+  if (!fs.statSync(extensionDir).isDirectory()) {
+    logger.error(
+      `Warning: unexpected file ${extensionDir} in extensions directory.`,
+    );
+    return null;
+  }
+
+  const configFilePath = path.join(extensionDir, EXTENSIONS_CONFIG_FILENAME);
+  if (!fs.existsSync(configFilePath)) {
+    logger.error(
+      `Warning: extension directory ${extensionDir} does not contain a config file ${configFilePath}.`,
+    );
+    return null;
+  }
+
+  try {
+    const configContent = fs.readFileSync(configFilePath, 'utf-8');
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    const config = JSON.parse(configContent) as ExtensionConfig;
+    if (!config.name || !config.version) {
+      logger.error(
+        `Invalid extension config in ${configFilePath}: missing name or version.`,
+      );
+      return null;
+    }
+
+    const installMetadata = loadInstallMetadata(extensionDir);
+
+    const contextFiles = getContextFileNames(config)
+      .map((contextFileName) => path.join(extensionDir, contextFileName))
+      .filter((contextFilePath) => fs.existsSync(contextFilePath));
+
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    return {
+      name: config.name,
+      version: config.version,
+      path: extensionDir,
+      contextFiles,
+      installMetadata,
+      mcpServers: config.mcpServers,
+      excludeTools: config.excludeTools,
+      isActive: true, // Barring any other signals extensions should be considered Active.
+    } as GeminiCLIExtension;
+  } catch (e) {
+    logger.error(
+      `Warning: error parsing extension config in ${configFilePath}: ${e}`,
+    );
+    return null;
+  }
+}
+
+function getContextFileNames(config: ExtensionConfig): string[] {
+  if (!config.contextFileName) {
+    return ['GEMINI.md'];
+  } else if (!Array.isArray(config.contextFileName)) {
+    return [config.contextFileName];
+  }
+  return config.contextFileName;
+}
+
+export function loadInstallMetadata(
+  extensionDir: string,
+): ExtensionInstallMetadata | undefined {
+  const metadataFilePath = path.join(extensionDir, INSTALL_METADATA_FILENAME);
+  try {
+    const configContent = fs.readFileSync(metadataFilePath, 'utf-8');
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    const metadata = JSON.parse(configContent) as ExtensionInstallMetadata;
+    return metadata;
+  } catch (e) {
+    logger.warn(
+      `Failed to load or parse extension install metadata at ${metadataFilePath}: ${e}`,
+    );
+    return undefined;
+  }
+}

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

@@ -0,0 +1,235 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import * as os from 'node:os';
+import { loadSettings, USER_SETTINGS_PATH } from './settings.js';
+import { debugLogger, checkPathTrust } from '@google/gemini-cli-core';
+
+const mocks = vi.hoisted(() => {
+  const suffix = Math.random().toString(36).slice(2);
+  return {
+    suffix,
+  };
+});
+
+vi.mock('node:os', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('node:os')>();
+  const path = await import('node:path');
+  return {
+    ...actual,
+    homedir: () => path.join(actual.tmpdir(), `gemini-home-${mocks.suffix}`),
+  };
+});
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  const path = await import('node:path');
+  const os = await import('node:os');
+  return {
+    ...actual,
+    GEMINI_DIR: '.gemini',
+    debugLogger: {
+      error: vi.fn(),
+    },
+    getErrorMessage: (error: unknown) => String(error),
+    homedir: () => path.join(os.tmpdir(), `gemini-home-${mocks.suffix}`),
+    checkPathTrust: vi.fn(() => ({ isTrusted: false })),
+    isHeadlessMode: vi.fn(() => true),
+  };
+});
+
+describe('loadSettings', () => {
+  const mockHomeDir = path.join(os.tmpdir(), `gemini-home-${mocks.suffix}`);
+  const mockWorkspaceDir = path.join(
+    os.tmpdir(),
+    `gemini-workspace-${mocks.suffix}`,
+  );
+  const mockGeminiHomeDir = path.join(mockHomeDir, '.gemini');
+  const mockGeminiWorkspaceDir = path.join(mockWorkspaceDir, '.gemini');
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    // Create the directories using the real fs
+    if (!fs.existsSync(mockGeminiHomeDir)) {
+      fs.mkdirSync(mockGeminiHomeDir, { recursive: true });
+    }
+    if (!fs.existsSync(mockGeminiWorkspaceDir)) {
+      fs.mkdirSync(mockGeminiWorkspaceDir, { recursive: true });
+    }
+
+    // Clean up settings files before each test
+    if (fs.existsSync(USER_SETTINGS_PATH)) {
+      fs.rmSync(USER_SETTINGS_PATH);
+    }
+    const workspaceSettingsPath = path.join(
+      mockGeminiWorkspaceDir,
+      'settings.json',
+    );
+    if (fs.existsSync(workspaceSettingsPath)) {
+      fs.rmSync(workspaceSettingsPath);
+    }
+  });
+
+  afterEach(() => {
+    try {
+      if (fs.existsSync(mockHomeDir)) {
+        fs.rmSync(mockHomeDir, { recursive: true, force: true });
+      }
+      if (fs.existsSync(mockWorkspaceDir)) {
+        fs.rmSync(mockWorkspaceDir, { recursive: true, force: true });
+      }
+    } catch (e) {
+      debugLogger.error('Failed to cleanup temp dirs', e);
+    }
+    vi.restoreAllMocks();
+  });
+
+  it('should load other top-level settings correctly', () => {
+    const settings = {
+      showMemoryUsage: true,
+      tools: {
+        core: ['tool1', 'tool2'],
+      },
+      mcpServers: {
+        server1: {
+          command: 'cmd',
+          args: ['arg'],
+        },
+      },
+      fileFiltering: {
+        respectGitIgnore: true,
+      },
+    };
+    fs.writeFileSync(USER_SETTINGS_PATH, JSON.stringify(settings));
+
+    const result = loadSettings(mockWorkspaceDir);
+    expect(result.showMemoryUsage).toBe(true);
+    expect(result.tools?.core).toEqual(['tool1', 'tool2']);
+    expect(result.mcpServers).toHaveProperty('server1');
+    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,
+      fileFiltering: {
+        respectGitIgnore: true,
+        enableRecursiveFileSearch: true,
+      },
+    };
+    fs.writeFileSync(USER_SETTINGS_PATH, JSON.stringify(userSettings));
+
+    const workspaceSettings = {
+      showMemoryUsage: true,
+      fileFiltering: {
+        respectGitIgnore: false,
+      },
+    };
+    const workspaceSettingsPath = path.join(
+      mockGeminiWorkspaceDir,
+      'settings.json',
+    );
+    fs.writeFileSync(workspaceSettingsPath, JSON.stringify(workspaceSettings));
+
+    const result = loadSettings(mockWorkspaceDir, true);
+    // Primitive value overwritten
+    expect(result.showMemoryUsage).toBe(true);
+
+    // Object value completely replaced (shallow merge behavior)
+    expect(result.fileFiltering?.respectGitIgnore).toBe(false);
+    expect(result.fileFiltering?.enableRecursiveFileSearch).toBeUndefined();
+  });
+
+  describe('security', () => {
+    it('should NOT load workspace settings if workspace is NOT trusted', () => {
+      const userSettings = { showMemoryUsage: false };
+      fs.writeFileSync(USER_SETTINGS_PATH, JSON.stringify(userSettings));
+
+      const workspaceSettings = { showMemoryUsage: true };
+      const workspaceSettingsPath = path.join(
+        mockGeminiWorkspaceDir,
+        'settings.json',
+      );
+      fs.writeFileSync(
+        workspaceSettingsPath,
+        JSON.stringify(workspaceSettings),
+      );
+
+      // checkPathTrust is mocked to return isTrusted: false by default
+      const result = loadSettings(mockWorkspaceDir);
+      expect(result.showMemoryUsage).toBe(false);
+    });
+
+    it('should load workspace settings if workspace IS trusted', () => {
+      vi.mocked(checkPathTrust).mockReturnValueOnce({
+        isTrusted: true,
+        source: 'file',
+      });
+      const userSettings = { showMemoryUsage: false };
+      fs.writeFileSync(USER_SETTINGS_PATH, JSON.stringify(userSettings));
+
+      const workspaceSettings = { showMemoryUsage: true };
+      const workspaceSettingsPath = path.join(
+        mockGeminiWorkspaceDir,
+        'settings.json',
+      );
+      fs.writeFileSync(
+        workspaceSettingsPath,
+        JSON.stringify(workspaceSettings),
+      );
+
+      const result = loadSettings(mockWorkspaceDir);
+      expect(result.showMemoryUsage).toBe(true);
+    });
+
+    it('should NOT allow workspace settings to override adminPolicyPaths or policyPaths even if trusted', () => {
+      vi.mocked(checkPathTrust).mockReturnValueOnce({
+        isTrusted: true,
+        source: 'file',
+      });
+      const userSettings = {
+        adminPolicyPaths: ['/trusted/admin'],
+        policyPaths: ['/trusted/user'],
+      };
+      fs.writeFileSync(USER_SETTINGS_PATH, JSON.stringify(userSettings));
+
+      const workspaceSettings = {
+        adminPolicyPaths: ['./malicious/admin'],
+        policyPaths: ['./malicious/user'],
+        showMemoryUsage: true,
+      };
+      const workspaceSettingsPath = path.join(
+        mockGeminiWorkspaceDir,
+        'settings.json',
+      );
+      fs.writeFileSync(
+        workspaceSettingsPath,
+        JSON.stringify(workspaceSettings),
+      );
+
+      const result = loadSettings(mockWorkspaceDir);
+      expect(result.showMemoryUsage).toBe(true);
+      expect(result.adminPolicyPaths).toEqual(['/trusted/admin']);
+      expect(result.policyPaths).toEqual(['/trusted/user']);
+    });
+  });
+});

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

@@ -0,0 +1,204 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+
+import {
+  type MCPServerConfig,
+  debugLogger,
+  GEMINI_DIR,
+  getErrorMessage,
+  type TelemetrySettings,
+  homedir,
+  checkPathTrust,
+  isHeadlessMode,
+} from '@google/gemini-cli-core';
+import stripJsonComments from 'strip-json-comments';
+
+export const USER_SETTINGS_DIR = path.join(homedir(), GEMINI_DIR);
+export const USER_SETTINGS_PATH = path.join(USER_SETTINGS_DIR, 'settings.json');
+
+// TODO: Ensure full compatibility with V2 nested settings structure (settings.schema.json).
+// This involves updating the interface and implementing migration logic to support legacy V1 (flat) settings,
+// similar to how packages/cli/src/config/settings.ts handles it.
+export interface Settings {
+  mcpServers?: Record<string, MCPServerConfig>;
+  tools?: {
+    allowed?: string[];
+    exclude?: string[];
+    core?: string[];
+  };
+  telemetry?: TelemetrySettings;
+  showMemoryUsage?: boolean;
+  checkpointing?: CheckpointingSettings;
+  folderTrust?: boolean;
+  general?: {
+    previewFeatures?: boolean;
+  };
+
+  // Git-aware file filtering settings
+  fileFiltering?: {
+    respectGitIgnore?: boolean;
+    respectGeminiIgnore?: boolean;
+    enableRecursiveFileSearch?: boolean;
+    customIgnoreFilePaths?: string[];
+  };
+  experimental?: {
+    enableAgents?: boolean;
+  };
+  policyPaths?: string[];
+  adminPolicyPaths?: string[];
+}
+
+export interface SettingsError {
+  message: string;
+  path: string;
+}
+
+export interface CheckpointingSettings {
+  enabled?: boolean;
+}
+
+/**
+ * Loads settings from user and workspace directories.
+ * Project settings override user settings if the workspace is trusted.
+ *
+ * How is it different to gemini-cli/cli: Returns already merged settings rather
+ * than `LoadedSettings` (unnecessary since we are not modifying users
+ * settings.json).
+ */
+export function loadSettings(
+  workspaceDir: string,
+  isTrustedOverride?: boolean,
+): Settings {
+  let userSettings: Settings = {};
+  let workspaceSettings: Settings = {};
+  const settingsErrors: SettingsError[] = [];
+
+  // Load user settings
+  try {
+    if (fs.existsSync(USER_SETTINGS_PATH)) {
+      const userContent = fs.readFileSync(USER_SETTINGS_PATH, 'utf-8');
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      const parsedUserSettings = JSON.parse(
+        stripJsonComments(userContent),
+      ) as Settings;
+      userSettings = resolveEnvVarsInObject(parsedUserSettings);
+    }
+  } catch (error: unknown) {
+    settingsErrors.push({
+      message: getErrorMessage(error),
+      path: USER_SETTINGS_PATH,
+    });
+  }
+
+  let isTrusted = isTrustedOverride;
+  if (isTrusted === undefined) {
+    const { isTrusted: trustResult } = checkPathTrust({
+      path: workspaceDir,
+      isFolderTrustEnabled: userSettings.folderTrust ?? true,
+      isHeadless: isHeadlessMode(),
+    });
+    isTrusted = trustResult ?? false;
+  }
+
+  const workspaceSettingsPath = path.join(
+    workspaceDir,
+    GEMINI_DIR,
+    'settings.json',
+  );
+
+  // Load workspace settings only if trusted
+  if (isTrusted) {
+    try {
+      if (fs.existsSync(workspaceSettingsPath)) {
+        const projectContent = fs.readFileSync(workspaceSettingsPath, 'utf-8');
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+        const parsedWorkspaceSettings = JSON.parse(
+          stripJsonComments(projectContent),
+        ) as Settings;
+        workspaceSettings = resolveEnvVarsInObject(parsedWorkspaceSettings);
+      }
+    } catch (error: unknown) {
+      settingsErrors.push({
+        message: getErrorMessage(error),
+        path: workspaceSettingsPath,
+      });
+    }
+  }
+
+  if (settingsErrors.length > 0) {
+    debugLogger.error('Errors loading settings:');
+    for (const error of settingsErrors) {
+      debugLogger.error(`  Path: ${error.path}`);
+      debugLogger.error(`  Message: ${error.message}`);
+    }
+  }
+
+  // If there are overlapping keys, the values of workspaceSettings will
+  // override values from userSettings
+  const mergedSettings = {
+    ...userSettings,
+    ...workspaceSettings,
+  };
+
+  // Security: ensure policyPaths and adminPolicyPaths are only loaded from trusted, user-level
+  // configuration and cannot be overridden by workspace-level settings, even if the
+  // workspace is trusted.
+  mergedSettings.policyPaths = userSettings.policyPaths;
+  mergedSettings.adminPolicyPaths = userSettings.adminPolicyPaths;
+
+  return mergedSettings;
+}
+
+function resolveEnvVarsInString(value: string): string {
+  const envVarRegex = /\$(?:(\w+)|{([^}]+)})/g; // Find $VAR_NAME or ${VAR_NAME}
+  return value.replace(
+    envVarRegex,
+    (match: string, varName1: string, varName2: string) => {
+      const varName = varName1 || varName2;
+      const envValue = process?.env?.[varName];
+      if (typeof envValue === 'string') {
+        return envValue;
+      }
+      return match;
+    },
+  );
+}
+
+function resolveEnvVarsInObject<T>(obj: T): T {
+  if (
+    obj === null ||
+    obj === undefined ||
+    typeof obj === 'boolean' ||
+    typeof obj === 'number'
+  ) {
+    return obj;
+  }
+
+  if (typeof obj === 'string') {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    return resolveEnvVarsInString(obj) as unknown as T;
+  }
+
+  if (Array.isArray(obj)) {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion, @typescript-eslint/no-unsafe-return
+    return obj.map((item) => resolveEnvVarsInObject(item)) as unknown as T;
+  }
+
+  if (typeof obj === 'object') {
+    const newObj = { ...obj } as T;
+    for (const key in newObj) {
+      if (Object.prototype.hasOwnProperty.call(newObj, key)) {
+        newObj[key] = resolveEnvVarsInObject(newObj[key]);
+      }
+    }
+    return newObj;
+  }
+
+  return obj;
+}

packages/a2a-server/src/http/app.ts

@@ -0,0 +1,413 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import express, { type Request } from 'express';
+
+import type { AgentCard, Message } from '@a2a-js/sdk';
+import {
+  type TaskStore,
+  DefaultRequestHandler,
+  InMemoryTaskStore,
+  DefaultExecutionEventBus,
+  type AgentExecutionEvent,
+  UnauthenticatedUser,
+} from '@a2a-js/sdk/server';
+import { A2AExpressApp, type UserBuilder } from '@a2a-js/sdk/server/express'; // Import server components
+import { v4 as uuidv4 } from 'uuid';
+import { logger } from '../utils/logger.js';
+import type { AgentSettings } from '../types.js';
+import { GCSTaskStore, NoOpTaskStore } from '../persistence/gcs.js';
+import { CoderAgentExecutor } from '../agent/executor.js';
+import { requestStorage } from './requestStorage.js';
+import { loadConfig, loadEnvironment, setTargetDir } from '../config/config.js';
+import { loadSettings } from '../config/settings.js';
+import { loadExtensions } from '../config/extension.js';
+import { commandRegistry } from '../commands/command-registry.js';
+import {
+  debugLogger,
+  SimpleExtensionLoader,
+  GitService,
+  checkPathTrust,
+  isHeadlessMode,
+} from '@google/gemini-cli-core';
+import type { Command, CommandArgument } from '../commands/types.js';
+
+type CommandResponse = {
+  name: string;
+  description: string;
+  arguments: CommandArgument[];
+  subCommands: CommandResponse[];
+};
+
+const coderAgentCard: AgentCard = {
+  name: 'Gemini SDLC Agent',
+  description:
+    'An agent that generates code based on natural language instructions and streams file outputs.',
+  url: 'http://localhost:41242/',
+  provider: {
+    organization: 'Google',
+    url: 'https://google.com',
+  },
+  protocolVersion: '0.3.0',
+  version: '0.0.2', // Incremented version
+  capabilities: {
+    streaming: true,
+    pushNotifications: false,
+    stateTransitionHistory: true,
+  },
+  securitySchemes: {
+    bearerAuth: {
+      type: 'http',
+      scheme: 'bearer',
+    },
+    basicAuth: {
+      type: 'http',
+      scheme: 'basic',
+    },
+  },
+  security: [{ bearerAuth: [] }, { basicAuth: [] }],
+  defaultInputModes: ['text'],
+  defaultOutputModes: ['text'],
+  skills: [
+    {
+      id: 'code_generation',
+      name: 'Code Generation',
+      description:
+        'Generates code snippets or complete files based on user requests, streaming the results.',
+      tags: ['code', 'development', 'programming'],
+      examples: [
+        'Write a python function to calculate fibonacci numbers.',
+        'Create an HTML file with a basic button that alerts "Hello!" when clicked.',
+      ],
+      inputModes: ['text'],
+      outputModes: ['text'],
+    },
+  ],
+  supportsAuthenticatedExtendedCard: false,
+};
+
+export function updateCoderAgentCardUrl(port: number) {
+  coderAgentCard.url = `http://localhost:${port}/`;
+}
+
+const customUserBuilder: UserBuilder = async (req: Request) => {
+  const auth = req.headers['authorization'];
+  if (auth) {
+    const scheme = auth.split(' ')[0];
+    logger.info(
+      `[customUserBuilder] Received Authorization header with scheme: ${scheme}`,
+    );
+  }
+  if (!auth) return new UnauthenticatedUser();
+
+  // 1. Bearer Auth
+  if (auth.startsWith('Bearer ')) {
+    const token = auth.substring(7);
+    if (token === 'valid-token') {
+      return { userName: 'bearer-user', isAuthenticated: true };
+    }
+  }
+
+  // 2. Basic Auth
+  if (auth.startsWith('Basic ')) {
+    const credentials = Buffer.from(auth.substring(6), 'base64').toString();
+    if (credentials === 'admin:password') {
+      return { userName: 'basic-user', isAuthenticated: true };
+    }
+  }
+
+  return new UnauthenticatedUser();
+};
+
+async function handleExecuteCommand(
+  req: express.Request,
+  res: express.Response,
+  context: {
+    config: Awaited<ReturnType<typeof loadConfig>>;
+    git: GitService | undefined;
+    agentExecutor: CoderAgentExecutor;
+  },
+) {
+  logger.info('[CoreAgent] Received /executeCommand request: ', req.body);
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+  const { command, args } = req.body;
+  try {
+    if (typeof command !== 'string') {
+      return res.status(400).json({ error: 'Invalid "command" field.' });
+    }
+
+    if (args && !Array.isArray(args)) {
+      return res.status(400).json({ error: '"args" field must be an array.' });
+    }
+
+    const commandToExecute = commandRegistry.get(command);
+
+    if (commandToExecute?.requiresWorkspace) {
+      if (!process.env['CODER_AGENT_WORKSPACE_PATH']) {
+        return res.status(400).json({
+          error: `Command "${command}" requires a workspace, but CODER_AGENT_WORKSPACE_PATH is not set.`,
+        });
+      }
+    }
+
+    if (!commandToExecute) {
+      return res.status(404).json({ error: `Command not found: ${command}` });
+    }
+
+    if (commandToExecute.streaming) {
+      const eventBus = new DefaultExecutionEventBus();
+      res.setHeader('Content-Type', 'text/event-stream');
+      const eventHandler = (event: AgentExecutionEvent) => {
+        const jsonRpcResponse = {
+          jsonrpc: '2.0',
+          // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+          id: 'taskId' in event ? event.taskId : (event as Message).messageId,
+          result: event,
+        };
+        res.write(`data: ${JSON.stringify(jsonRpcResponse)}\n`);
+      };
+      eventBus.on('event', eventHandler);
+
+      await commandToExecute.execute({ ...context, eventBus }, args ?? []);
+
+      eventBus.off('event', eventHandler);
+      eventBus.finished();
+      return res.end(); // Explicit return for streaming path
+    } else {
+      const result = await commandToExecute.execute(context, args ?? []);
+      logger.info('[CoreAgent] Sending /executeCommand response: ', result);
+      return res.status(200).json(result);
+    }
+  } catch (e) {
+    logger.error(
+      `Error executing /executeCommand: ${command} with args: ${JSON.stringify(
+        args,
+      )}`,
+      e,
+    );
+    const errorMessage =
+      e instanceof Error ? e.message : 'Unknown error executing command';
+    return res.status(500).json({ error: errorMessage });
+  }
+}
+
+export async function createApp() {
+  try {
+    // Load the server configuration once on startup.
+    const workspaceRoot = setTargetDir(undefined);
+    loadEnvironment();
+
+    // Use a temporary settings load to check if folder trust is enabled.
+    // This is similar to how the CLI handles the initial trust check.
+    const initialSettings = loadSettings(workspaceRoot, false);
+    const { isTrusted } = checkPathTrust({
+      path: workspaceRoot,
+      isFolderTrustEnabled: initialSettings.folderTrust ?? true,
+      isHeadless: isHeadlessMode(),
+    });
+
+    const settings = loadSettings(workspaceRoot, isTrusted ?? false);
+    const extensions = loadExtensions(workspaceRoot);
+    const config = await loadConfig(
+      settings,
+      new SimpleExtensionLoader(extensions),
+      'a2a-server',
+      isTrusted ?? false,
+    );
+
+    let git: GitService | undefined;
+    if (config.getCheckpointingEnabled()) {
+      git = new GitService(config.getTargetDir(), config.storage);
+      await git.initialize();
+    }
+
+    // loadEnvironment() is called within getConfig now
+    const bucketName = process.env['GCS_BUCKET_NAME'];
+    let taskStoreForExecutor: TaskStore;
+    let taskStoreForHandler: TaskStore;
+
+    if (bucketName) {
+      logger.info(`Using GCSTaskStore with bucket: ${bucketName}`);
+      const gcsTaskStore = new GCSTaskStore(bucketName);
+      taskStoreForExecutor = gcsTaskStore;
+      taskStoreForHandler = new NoOpTaskStore(gcsTaskStore);
+    } else {
+      logger.info('Using InMemoryTaskStore');
+      const inMemoryTaskStore = new InMemoryTaskStore();
+      taskStoreForExecutor = inMemoryTaskStore;
+      taskStoreForHandler = inMemoryTaskStore;
+    }
+
+    const agentExecutor = new CoderAgentExecutor(taskStoreForExecutor);
+
+    const context = { config, git, agentExecutor };
+
+    const requestHandler = new DefaultRequestHandler(
+      coderAgentCard,
+      taskStoreForHandler,
+      agentExecutor,
+    );
+
+    let expressApp = express();
+    expressApp.use((req, res, next) => {
+      requestStorage.run({ req }, next);
+    });
+
+    const appBuilder = new A2AExpressApp(requestHandler, customUserBuilder);
+    expressApp = appBuilder.setupRoutes(expressApp, '');
+    expressApp.use(express.json());
+
+    expressApp.post('/tasks', async (req, res) => {
+      try {
+        const taskId = uuidv4();
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+        const agentSettings = req.body.agentSettings as
+          | AgentSettings
+          | undefined;
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+        const contextId = req.body.contextId || uuidv4();
+        const wrapper = await agentExecutor.createTask(
+          taskId,
+          contextId,
+          agentSettings,
+        );
+        await taskStoreForExecutor.save(wrapper.toSDKTask());
+        res.status(201).json(wrapper.id);
+      } catch (error) {
+        logger.error('[CoreAgent] Error creating task:', error);
+        const errorMessage =
+          error instanceof Error
+            ? error.message
+            : 'Unknown error creating task';
+        res.status(500).send({ error: errorMessage });
+      }
+    });
+
+    expressApp.post('/executeCommand', (req, res) => {
+      void handleExecuteCommand(req, res, context);
+    });
+
+    expressApp.get('/listCommands', (req, res) => {
+      try {
+        const transformCommand = (
+          command: Command,
+          visited: string[],
+        ): CommandResponse | undefined => {
+          const commandName = command.name;
+          if (visited.includes(commandName)) {
+            debugLogger.warn(
+              `Command ${commandName} already inserted in the response, skipping`,
+            );
+            return undefined;
+          }
+
+          return {
+            name: command.name,
+            description: command.description,
+            arguments: command.arguments ?? [],
+            subCommands: (command.subCommands ?? [])
+              .map((subCommand) =>
+                transformCommand(subCommand, visited.concat(commandName)),
+              )
+              .filter(
+                (subCommand): subCommand is CommandResponse => !!subCommand,
+              ),
+          };
+        };
+
+        const commands = commandRegistry
+          .getAllCommands()
+          .filter((command) => command.topLevel)
+          .map((command) => transformCommand(command, []));
+
+        return res.status(200).json({ commands });
+      } catch (e) {
+        logger.error('Error executing /listCommands:', e);
+        const errorMessage =
+          e instanceof Error ? e.message : 'Unknown error listing commands';
+        return res.status(500).json({ error: errorMessage });
+      }
+    });
+
+    expressApp.get('/tasks/metadata', async (req, res) => {
+      // This endpoint is only meaningful if the task store is in-memory.
+      if (!(taskStoreForExecutor instanceof InMemoryTaskStore)) {
+        res.status(501).send({
+          error:
+            'Listing all task metadata is only supported when using InMemoryTaskStore.',
+        });
+      }
+      try {
+        const wrappers = agentExecutor.getAllTasks();
+        if (wrappers && wrappers.length > 0) {
+          const tasksMetadata = await Promise.all(
+            wrappers.map((wrapper) => wrapper.task.getMetadata()),
+          );
+          res.status(200).json(tasksMetadata);
+        } else {
+          res.status(204).send();
+        }
+      } catch (error) {
+        logger.error('[CoreAgent] Error getting all task metadata:', error);
+        const errorMessage =
+          error instanceof Error
+            ? error.message
+            : 'Unknown error getting task metadata';
+        res.status(500).send({ error: errorMessage });
+      }
+    });
+
+    expressApp.get('/tasks/:taskId/metadata', async (req, res) => {
+      const taskId = req.params.taskId;
+      let wrapper = agentExecutor.getTask(taskId);
+      if (!wrapper) {
+        const sdkTask = await taskStoreForExecutor.load(taskId);
+        if (sdkTask) {
+          wrapper = await agentExecutor.reconstruct(sdkTask);
+        }
+      }
+      if (!wrapper) {
+        res.status(404).send({ error: 'Task not found' });
+        return;
+      }
+      res.json({ metadata: await wrapper.task.getMetadata() });
+    });
+    return expressApp;
+  } catch (error) {
+    logger.error('[CoreAgent] Error during startup:', error);
+    process.exit(1);
+  }
+}
+
+export async function main() {
+  try {
+    const expressApp = await createApp();
+    const port = Number(process.env['CODER_AGENT_PORT'] || 0);
+
+    const server = expressApp.listen(port, 'localhost', () => {
+      const address = server.address();
+      let actualPort;
+      if (process.env['CODER_AGENT_PORT']) {
+        actualPort = process.env['CODER_AGENT_PORT'];
+      } else if (address && typeof address !== 'string') {
+        actualPort = address.port;
+      } else {
+        throw new Error('[Core Agent] Could not find port number.');
+      }
+      updateCoderAgentCardUrl(Number(actualPort));
+      logger.info(
+        `[CoreAgent] Agent Server started on http://localhost:${actualPort}`,
+      );
+      logger.info(
+        `[CoreAgent] Agent Card: http://localhost:${actualPort}/.well-known/agent-card.json`,
+      );
+      logger.info('[CoreAgent] Press Ctrl+C to stop the server');
+    });
+  } catch (error) {
+    logger.error('[CoreAgent] Error during startup:', error);
+    process.exit(1);
+  }
+}

packages/a2a-server/src/http/endpoints.test.ts

@@ -0,0 +1,162 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, beforeAll, afterAll, vi } from 'vitest';
+import request from 'supertest';
+import type express from 'express';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import * as os from 'node:os';
+import type { Server } from 'node:http';
+import type { AddressInfo } from 'node:net';
+
+import { createApp, updateCoderAgentCardUrl } from './app.js';
+import type { TaskMetadata } from '../types.js';
+import { createMockConfig } from '../utils/testing_utils.js';
+import { debugLogger, type Config } from '@google/gemini-cli-core';
+
+// Mock the logger to avoid polluting test output
+// Comment out to help debug
+vi.mock('../utils/logger.js', () => ({
+  logger: { info: vi.fn(), warn: vi.fn(), error: vi.fn() },
+}));
+
+// Mock Task.create to avoid its complex setup
+vi.mock('../agent/task.js', () => {
+  class MockTask {
+    id: string;
+    contextId: string;
+    taskState = 'submitted';
+    config = {
+      getContentGeneratorConfig: vi
+        .fn()
+        .mockReturnValue({ model: 'gemini-pro' }),
+    };
+    geminiClient = {
+      initialize: vi.fn().mockResolvedValue(undefined),
+    };
+    constructor(id: string, contextId: string) {
+      this.id = id;
+      this.contextId = contextId;
+    }
+    static create = vi
+      .fn()
+      .mockImplementation((id, contextId) =>
+        Promise.resolve(new MockTask(id, contextId)),
+      );
+    getMetadata = vi.fn().mockImplementation(async () => ({
+      id: this.id,
+      contextId: this.contextId,
+      taskState: this.taskState,
+      model: 'gemini-pro',
+      mcpServers: [],
+      availableTools: [],
+    }));
+  }
+  return { Task: MockTask };
+});
+
+vi.mock('../config/config.js', async () => {
+  const actual = await vi.importActual('../config/config.js');
+  return {
+    ...actual,
+    loadConfig: vi
+      .fn()
+      .mockImplementation(async () => createMockConfig({}) as Config),
+  };
+});
+
+describe('Agent Server Endpoints', () => {
+  let app: express.Express;
+  let server: Server;
+  let testWorkspace: string;
+
+  const createTask = (contextId: string) =>
+    request(app)
+      .post('/tasks')
+      .send({
+        contextId,
+        agentSettings: {
+          kind: 'agent-settings',
+          workspacePath: testWorkspace,
+        },
+      })
+      .set('Content-Type', 'application/json');
+
+  beforeAll(async () => {
+    // Create a unique temporary directory for the workspace to avoid conflicts
+    testWorkspace = fs.mkdtempSync(
+      path.join(os.tmpdir(), 'gemini-agent-test-'),
+    );
+    app = await createApp();
+    await new Promise<void>((resolve) => {
+      server = app.listen(0, () => {
+        const port = (server.address() as AddressInfo).port;
+        updateCoderAgentCardUrl(port);
+        resolve();
+      });
+    });
+  });
+
+  afterAll(async () => {
+    if (server) {
+      await new Promise<void>((resolve, reject) => {
+        server.close((err) => {
+          if (err) return reject(err);
+          resolve();
+        });
+      });
+    }
+
+    if (testWorkspace) {
+      try {
+        fs.rmSync(testWorkspace, { recursive: true, force: true });
+      } catch (e) {
+        debugLogger.warn(`Could not remove temp dir '${testWorkspace}':`, e);
+      }
+    }
+  });
+
+  it('should create a new task via POST /tasks', async () => {
+    const response = await createTask('test-context');
+    expect(response.status).toBe(201);
+    expect(response.body).toBeTypeOf('string'); // Should return the task ID
+  }, 7000);
+
+  it('should get metadata for a specific task via GET /tasks/:taskId/metadata', async () => {
+    const createResponse = await createTask('test-context-2');
+    const taskId = createResponse.body;
+    const response = await request(app).get(`/tasks/${taskId}/metadata`);
+    expect(response.status).toBe(200);
+    expect(response.body.metadata.id).toBe(taskId);
+  }, 6000);
+
+  it('should get metadata for all tasks via GET /tasks/metadata', async () => {
+    const createResponse = await createTask('test-context-3');
+    const taskId = createResponse.body;
+    const response = await request(app).get('/tasks/metadata');
+    expect(response.status).toBe(200);
+    expect(Array.isArray(response.body)).toBe(true);
+    expect(response.body.length).toBeGreaterThan(0);
+    const taskMetadata = response.body.find(
+      (m: TaskMetadata) => m.id === taskId,
+    );
+    expect(taskMetadata).toBeDefined();
+  });
+
+  it('should return 404 for a non-existent task', async () => {
+    const response = await request(app).get('/tasks/fake-task/metadata');
+    expect(response.status).toBe(404);
+  });
+
+  it('should return agent metadata via GET /.well-known/agent-card.json', async () => {
+    const response = await request(app).get('/.well-known/agent-card.json');
+    const port = (server.address() as AddressInfo).port;
+    expect(response.status).toBe(200);
+    expect(response.body.name).toBe('Gemini SDLC Agent');
+    expect(response.body.url).toBe(`http://localhost:${port}/`);
+  });
+});

packages/a2a-server/src/http/requestStorage.ts

@@ -0,0 +1,10 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type express from 'express';
+import { AsyncLocalStorage } from 'node:async_hooks';
+
+export const requestStorage = new AsyncLocalStorage<{ req: express.Request }>();

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

@@ -0,0 +1,34 @@
+#!/usr/bin/env node
+
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as url from 'node:url';
+import * as path from 'node:path';
+
+import { logger } from '../utils/logger.js';
+import { main } from './app.js';
+
+// Check if the module is the main script being run
+const isMainModule =
+  path.basename(process.argv[1]) ===
+  path.basename(url.fileURLToPath(import.meta.url));
+
+if (
+  import.meta.url.startsWith('file:') &&
+  isMainModule &&
+  process.env['NODE_ENV'] !== 'test'
+) {
+  process.on('uncaughtException', (error) => {
+    logger.error('Unhandled exception:', error);
+    process.exit(1);
+  });
+
+  main().catch((error) => {
+    logger.error('[CoreAgent] Unhandled error in main:', error);
+    process.exit(1);
+  });
+}

packages/a2a-server/src/index.ts

@@ -0,0 +1,9 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export * from './agent/executor.js';
+export * from './http/app.js';
+export * from './types.js';

packages/a2a-server/src/persistence/gcs.test.ts

@@ -0,0 +1,446 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { Storage } from '@google-cloud/storage';
+import * as fse from 'fs-extra';
+import * as tar from 'tar';
+import { gzipSync, gunzipSync } from 'node:zlib';
+import { v4 as uuidv4 } from 'uuid';
+import type { Task as SDKTask } from '@a2a-js/sdk';
+import type { TaskStore } from '@a2a-js/sdk/server';
+import {
+  describe,
+  it,
+  expect,
+  beforeEach,
+  vi,
+  type Mocked,
+  type MockedClass,
+  type Mock,
+} from 'vitest';
+
+import { GCSTaskStore, NoOpTaskStore } from './gcs.js';
+import { logger } from '../utils/logger.js';
+import * as configModule from '../config/config.js';
+import { getPersistedState, METADATA_KEY } from '../types.js';
+
+// Mock dependencies
+const fsMocks = vi.hoisted(() => ({
+  readdir: vi.fn(),
+  createReadStream: vi.fn(),
+}));
+
+vi.mock('@google-cloud/storage');
+vi.mock('fs-extra', () => ({
+  pathExists: vi.fn(),
+  readdir: vi.fn(),
+  remove: vi.fn(),
+  ensureDir: vi.fn(),
+  createReadStream: vi.fn(),
+}));
+vi.mock('node:fs', async () => {
+  const actual = await vi.importActual<typeof import('node:fs')>('node:fs');
+  return {
+    ...actual,
+    promises: {
+      ...actual.promises,
+      readdir: fsMocks.readdir,
+    },
+    createReadStream: fsMocks.createReadStream,
+  };
+});
+vi.mock('fs', async () => {
+  const actual = await vi.importActual<typeof import('node:fs')>('node:fs');
+  return {
+    ...actual,
+    promises: {
+      ...actual.promises,
+      readdir: fsMocks.readdir,
+    },
+    createReadStream: fsMocks.createReadStream,
+  };
+});
+vi.mock('tar', async () => {
+  const actualFs = await vi.importActual<typeof import('node:fs')>('node:fs');
+  return {
+    c: vi.fn(({ file }) => {
+      if (file) {
+        actualFs.writeFileSync(file, Buffer.from('dummy tar content'));
+      }
+      return Promise.resolve();
+    }),
+    x: vi.fn().mockResolvedValue(undefined),
+    t: vi.fn().mockResolvedValue(undefined),
+    r: vi.fn().mockResolvedValue(undefined),
+    u: vi.fn().mockResolvedValue(undefined),
+  };
+});
+vi.mock('zlib');
+vi.mock('uuid');
+vi.mock('../utils/logger.js', () => ({
+  logger: {
+    info: vi.fn(),
+    warn: vi.fn(),
+    error: vi.fn(),
+    debug: vi.fn(),
+  },
+}));
+vi.mock('../config/config.js', () => ({
+  setTargetDir: vi.fn(),
+}));
+vi.mock('node:stream/promises', () => ({
+  pipeline: vi.fn(),
+}));
+vi.mock('../types.js', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('../types.js')>();
+  return {
+    ...actual,
+    getPersistedState: vi.fn(),
+  };
+});
+
+const mockStorage = Storage as MockedClass<typeof Storage>;
+const mockFse = fse as Mocked<typeof fse>;
+const mockCreateReadStream = fsMocks.createReadStream;
+const mockTar = tar as Mocked<typeof tar>;
+const mockGzipSync = gzipSync as Mock;
+const mockGunzipSync = gunzipSync as Mock;
+const mockUuidv4 = uuidv4 as Mock;
+const mockSetTargetDir = configModule.setTargetDir as Mock;
+const mockGetPersistedState = getPersistedState as Mock;
+const TEST_METADATA_KEY = METADATA_KEY || '__persistedState';
+
+type MockWriteStream = {
+  emit: Mock<(event: string, ...args: unknown[]) => boolean>;
+  removeListener: Mock<
+    (event: string, cb: (error?: Error | null) => void) => MockWriteStream
+  >;
+  once: Mock<
+    (event: string, cb: (error?: Error | null) => void) => MockWriteStream
+  >;
+  on: Mock<
+    (event: string, cb: (error?: Error | null) => void) => MockWriteStream
+  >;
+  destroy: Mock<() => void>;
+  write: Mock<(chunk: unknown, encoding?: unknown, cb?: unknown) => boolean>;
+  end: Mock<(cb?: unknown) => void>;
+  destroyed: boolean;
+};
+
+type MockFile = {
+  save: Mock<(data: Buffer | string) => Promise<void>>;
+  download: Mock<() => Promise<[Buffer]>>;
+  exists: Mock<() => Promise<[boolean]>>;
+  createWriteStream: Mock<() => MockWriteStream>;
+};
+
+type MockBucket = {
+  exists: Mock<() => Promise<[boolean]>>;
+  file: Mock<(path: string) => MockFile>;
+  name: string;
+};
+
+type MockStorageInstance = {
+  bucket: Mock<(name: string) => MockBucket>;
+  getBuckets: Mock<() => Promise<[Array<{ name: string }>]>>;
+  createBucket: Mock<(name: string) => Promise<[MockBucket]>>;
+};
+
+describe('GCSTaskStore', () => {
+  let bucketName: string;
+  let mockBucket: MockBucket;
+  let mockFile: MockFile;
+  let mockWriteStream: MockWriteStream;
+  let mockStorageInstance: MockStorageInstance;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    bucketName = 'test-bucket';
+
+    mockWriteStream = {
+      emit: vi.fn().mockReturnValue(true),
+      removeListener: vi.fn().mockReturnValue(mockWriteStream),
+      on: vi.fn((event, cb) => {
+        if (event === 'finish') setTimeout(cb, 0); // Simulate async finish
+        return mockWriteStream;
+      }),
+      once: vi.fn((event, cb) => {
+        if (event === 'finish') setTimeout(cb, 0); // Simulate async finish        return mockWriteStream;
+      }),
+      destroy: vi.fn(),
+      write: vi.fn().mockReturnValue(true),
+      end: vi.fn(),
+      destroyed: false,
+    };
+
+    mockFile = {
+      save: vi.fn().mockResolvedValue(undefined),
+      download: vi.fn().mockResolvedValue([Buffer.from('')]),
+      exists: vi.fn().mockResolvedValue([true]),
+      createWriteStream: vi.fn().mockReturnValue(mockWriteStream),
+    };
+
+    mockBucket = {
+      exists: vi.fn().mockResolvedValue([true]),
+      file: vi.fn().mockReturnValue(mockFile),
+      name: bucketName,
+    };
+
+    mockStorageInstance = {
+      bucket: vi.fn().mockReturnValue(mockBucket),
+      getBuckets: vi.fn().mockResolvedValue([[{ name: bucketName }]]),
+      createBucket: vi.fn().mockResolvedValue([mockBucket]),
+    };
+    mockStorage.mockReturnValue(mockStorageInstance as unknown as Storage);
+
+    mockUuidv4.mockReturnValue('test-uuid');
+    mockSetTargetDir.mockReturnValue('/tmp/workdir');
+    mockGetPersistedState.mockReturnValue({
+      _agentSettings: {},
+      _taskState: 'submitted',
+    });
+    (fse.pathExists as Mock).mockResolvedValue(true);
+    fsMocks.readdir.mockResolvedValue(['file1.txt']);
+    mockFse.remove.mockResolvedValue(undefined);
+    mockFse.ensureDir.mockResolvedValue(undefined);
+    mockGzipSync.mockReturnValue(Buffer.from('compressed'));
+    mockGunzipSync.mockReturnValue(Buffer.from('{}'));
+    mockCreateReadStream.mockReturnValue({ on: vi.fn(), pipe: vi.fn() });
+    mockFse.createReadStream.mockReturnValue({
+      on: vi.fn(),
+      pipe: vi.fn(),
+    } as unknown as import('node:fs').ReadStream);
+  });
+
+  describe('Constructor & Initialization', () => {
+    it('should initialize and check bucket existence', async () => {
+      const store = new GCSTaskStore(bucketName);
+      await store['ensureBucketInitialized']();
+      expect(mockStorage).toHaveBeenCalledTimes(1);
+      expect(mockStorageInstance.getBuckets).toHaveBeenCalled();
+      expect(logger.info).toHaveBeenCalledWith(
+        expect.stringContaining('Bucket test-bucket exists'),
+      );
+    });
+
+    it('should create bucket if it does not exist', async () => {
+      mockStorageInstance.getBuckets.mockResolvedValue([[]]);
+      const store = new GCSTaskStore(bucketName);
+      await store['ensureBucketInitialized']();
+      expect(mockStorageInstance.createBucket).toHaveBeenCalledWith(bucketName);
+      expect(logger.info).toHaveBeenCalledWith(
+        expect.stringContaining('Bucket test-bucket created successfully'),
+      );
+    });
+
+    it('should throw if bucket creation fails', async () => {
+      mockStorageInstance.getBuckets.mockResolvedValue([[]]);
+      mockStorageInstance.createBucket.mockRejectedValue(
+        new Error('Create failed'),
+      );
+      const store = new GCSTaskStore(bucketName);
+      await expect(store['ensureBucketInitialized']()).rejects.toThrow(
+        'Failed to create GCS bucket test-bucket: Error: Create failed',
+      );
+    });
+  });
+
+  describe('save', () => {
+    const mockTask: SDKTask = {
+      id: 'task1',
+      contextId: 'ctx1',
+      kind: 'task',
+      status: { state: 'working' },
+      metadata: {},
+    };
+
+    it('should save metadata and workspace', async () => {
+      const store = new GCSTaskStore(bucketName);
+      await store.save(mockTask);
+
+      expect(mockFile.save).toHaveBeenCalledTimes(1);
+      expect(mockTar.c).toHaveBeenCalledTimes(1);
+      expect(mockFse.remove).toHaveBeenCalledTimes(1);
+      expect(logger.info).toHaveBeenCalledWith(
+        expect.stringContaining('metadata saved to GCS'),
+      );
+      expect(logger.info).toHaveBeenCalledWith(
+        expect.stringContaining('workspace saved to GCS'),
+      );
+    });
+
+    it('should handle tar creation failure', async () => {
+      mockFse.pathExists.mockImplementation(
+        async (path) =>
+          !path.toString().includes('task-task1-workspace-test-uuid.tar.gz'),
+      );
+      const store = new GCSTaskStore(bucketName);
+      await expect(store.save(mockTask)).rejects.toThrow(
+        'tar.c command failed to create',
+      );
+    });
+
+    it('should throw an error if taskId contains path traversal sequences', async () => {
+      const store = new GCSTaskStore('test-bucket');
+      const maliciousTask: SDKTask = {
+        id: '../../../malicious-task',
+        metadata: {
+          _internal: {
+            agentSettings: {
+              cacheDir: '/tmp/cache',
+              dataDir: '/tmp/data',
+              logDir: '/tmp/logs',
+              tempDir: '/tmp/temp',
+            },
+            taskState: 'working',
+          },
+        },
+        kind: 'task',
+        status: {
+          state: 'working',
+          timestamp: new Date().toISOString(),
+        },
+        contextId: 'test-context',
+        history: [],
+        artifacts: [],
+      };
+      await expect(store.save(maliciousTask)).rejects.toThrow(
+        'Invalid taskId: ../../../malicious-task',
+      );
+    });
+  });
+
+  describe('load', () => {
+    it('should load task metadata and workspace', async () => {
+      mockGunzipSync.mockReturnValue(
+        Buffer.from(
+          JSON.stringify({
+            [TEST_METADATA_KEY]: {
+              _agentSettings: {},
+              _taskState: 'submitted',
+            },
+            _contextId: 'ctx1',
+          }),
+        ),
+      );
+      mockFile.download.mockResolvedValue([Buffer.from('compressed metadata')]);
+      mockFile.download.mockResolvedValueOnce([
+        Buffer.from('compressed metadata'),
+      ]);
+      mockBucket.file = vi.fn((path) => {
+        const newMockFile = { ...mockFile };
+        if (path.includes('metadata')) {
+          newMockFile.download = vi
+            .fn()
+            .mockResolvedValue([Buffer.from('compressed metadata')]);
+          newMockFile.exists = vi.fn().mockResolvedValue([true]);
+        } else {
+          newMockFile.download = vi
+            .fn()
+            .mockResolvedValue([Buffer.from('compressed workspace')]);
+          newMockFile.exists = vi.fn().mockResolvedValue([true]);
+        }
+        return newMockFile;
+      });
+
+      const store = new GCSTaskStore(bucketName);
+      const task = await store.load('task1');
+
+      expect(task).toBeDefined();
+      expect(task?.id).toBe('task1');
+      expect(mockBucket.file).toHaveBeenCalledWith(
+        'tasks/task1/metadata.tar.gz',
+      );
+      expect(mockBucket.file).toHaveBeenCalledWith(
+        'tasks/task1/workspace.tar.gz',
+      );
+      expect(mockTar.x).toHaveBeenCalledTimes(1);
+      expect(mockFse.remove).toHaveBeenCalledTimes(1);
+    });
+
+    it('should return undefined if metadata not found', async () => {
+      mockFile.exists.mockResolvedValue([false]);
+      const store = new GCSTaskStore(bucketName);
+      const task = await store.load('task1');
+      expect(task).toBeUndefined();
+      expect(mockBucket.file).toHaveBeenCalledWith(
+        'tasks/task1/metadata.tar.gz',
+      );
+    });
+
+    it('should load metadata even if workspace not found', async () => {
+      mockGunzipSync.mockReturnValue(
+        Buffer.from(
+          JSON.stringify({
+            [TEST_METADATA_KEY]: {
+              _agentSettings: {},
+              _taskState: 'submitted',
+            },
+            _contextId: 'ctx1',
+          }),
+        ),
+      );
+
+      mockBucket.file = vi.fn((path) => {
+        const newMockFile = { ...mockFile };
+        if (path.includes('workspace.tar.gz')) {
+          newMockFile.exists = vi.fn().mockResolvedValue([false]);
+        } else {
+          newMockFile.exists = vi.fn().mockResolvedValue([true]);
+          newMockFile.download = vi
+            .fn()
+            .mockResolvedValue([Buffer.from('compressed metadata')]);
+        }
+        return newMockFile;
+      });
+
+      const store = new GCSTaskStore(bucketName);
+      const task = await store.load('task1');
+
+      expect(task).toBeDefined();
+      expect(mockTar.x).not.toHaveBeenCalled();
+      expect(logger.info).toHaveBeenCalledWith(
+        expect.stringContaining('workspace archive not found'),
+      );
+    });
+  });
+
+  it('should throw an error if taskId contains path traversal sequences', async () => {
+    const store = new GCSTaskStore('test-bucket');
+    const maliciousTaskId = '../../../malicious-task';
+    await expect(store.load(maliciousTaskId)).rejects.toThrow(
+      `Invalid taskId: ${maliciousTaskId}`,
+    );
+  });
+});
+
+describe('NoOpTaskStore', () => {
+  let realStore: TaskStore;
+  let noOpStore: NoOpTaskStore;
+
+  beforeEach(() => {
+    // Create a mock of the real store to delegate to
+    realStore = {
+      save: vi.fn(),
+      load: vi.fn().mockResolvedValue({ id: 'task-123' } as SDKTask),
+    };
+    noOpStore = new NoOpTaskStore(realStore);
+  });
+
+  it("should not call the real store's save method", async () => {
+    const mockTask: SDKTask = { id: 'test-task' } as SDKTask;
+    await noOpStore.save(mockTask);
+    expect(realStore.save).not.toHaveBeenCalled();
+  });
+
+  it('should delegate the load method to the real store', async () => {
+    const taskId = 'task-123';
+    const result = await noOpStore.load(taskId);
+    expect(realStore.load).toHaveBeenCalledWith(taskId);
+    expect(result).toBeDefined();
+    expect(result?.id).toBe(taskId);
+  });
+});

packages/a2a-server/src/persistence/gcs.ts

@@ -0,0 +1,319 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { Storage } from '@google-cloud/storage';
+import { gzipSync, gunzipSync } from 'node:zlib';
+import * as tar from 'tar';
+import * as fse from 'fs-extra';
+import { promises as fsPromises, createReadStream } from 'node:fs';
+import { tmpdir } from '@google/gemini-cli-core';
+import { join } from 'node:path';
+import type { Task as SDKTask } from '@a2a-js/sdk';
+import type { TaskStore } from '@a2a-js/sdk/server';
+import { logger } from '../utils/logger.js';
+import { setTargetDir } from '../config/config.js';
+import { getPersistedState, type PersistedTaskMetadata } from '../types.js';
+import { v4 as uuidv4 } from 'uuid';
+
+type ObjectType = 'metadata' | 'workspace';
+
+const getTmpArchiveFilename = (taskId: string): string =>
+  `task-${taskId}-workspace-${uuidv4()}.tar.gz`;
+
+// Validate the taskId to prevent path traversal attacks by ensuring it only contains safe characters.
+const isTaskIdValid = (taskId: string): boolean => {
+  // Allow only alphanumeric characters, dashes, and underscores, and ensure it's not empty.
+  const validTaskIdRegex = /^[a-zA-Z0-9_-]+$/;
+  return validTaskIdRegex.test(taskId);
+};
+
+export class GCSTaskStore implements TaskStore {
+  private storage: Storage;
+  private bucketName: string;
+  private bucketInitialized: Promise<void>;
+
+  constructor(bucketName: string) {
+    if (!bucketName) {
+      throw new Error('GCS bucket name is required.');
+    }
+    this.storage = new Storage();
+    this.bucketName = bucketName;
+    logger.info(`GCSTaskStore initializing with bucket: ${this.bucketName}`);
+    // Prerequisites: user account or service account must have storage admin IAM role
+    // and the bucket name must be unique.
+    this.bucketInitialized = this.initializeBucket();
+  }
+
+  private async initializeBucket(): Promise<void> {
+    try {
+      const [buckets] = await this.storage.getBuckets();
+      const exists = buckets.some((bucket) => bucket.name === this.bucketName);
+
+      if (!exists) {
+        logger.info(
+          `Bucket ${this.bucketName} does not exist in the list. Attempting to create...`,
+        );
+        try {
+          await this.storage.createBucket(this.bucketName);
+          logger.info(`Bucket ${this.bucketName} created successfully.`);
+        } catch (createError) {
+          logger.info(
+            `Failed to create bucket ${this.bucketName}: ${createError}`,
+          );
+          throw new Error(
+            `Failed to create GCS bucket ${this.bucketName}: ${createError}`,
+          );
+        }
+      } else {
+        logger.info(`Bucket ${this.bucketName} exists.`);
+      }
+    } catch (error) {
+      logger.info(
+        `Error during bucket initialization for ${this.bucketName}: ${error}`,
+      );
+      throw new Error(
+        `Failed to initialize GCS bucket ${this.bucketName}: ${error}`,
+      );
+    }
+  }
+
+  private async ensureBucketInitialized(): Promise<void> {
+    await this.bucketInitialized;
+  }
+
+  private getObjectPath(taskId: string, type: ObjectType): string {
+    if (!isTaskIdValid(taskId)) {
+      throw new Error(`Invalid taskId: ${taskId}`);
+    }
+    return `tasks/${taskId}/${type}.tar.gz`;
+  }
+
+  async save(task: SDKTask): Promise<void> {
+    await this.ensureBucketInitialized();
+    const taskId = task.id;
+    const persistedState = getPersistedState(
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      task.metadata as PersistedTaskMetadata,
+    );
+
+    if (!persistedState) {
+      throw new Error(`Task ${taskId} is missing persisted state in metadata.`);
+    }
+    const workDir = process.cwd();
+
+    const metadataObjectPath = this.getObjectPath(taskId, 'metadata');
+    const workspaceObjectPath = this.getObjectPath(taskId, 'workspace');
+
+    const dataToStore = task.metadata;
+
+    try {
+      const jsonString = JSON.stringify(dataToStore);
+      const compressedMetadata = gzipSync(Buffer.from(jsonString));
+      const metadataFile = this.storage
+        .bucket(this.bucketName)
+        .file(metadataObjectPath);
+      await metadataFile.save(compressedMetadata, {
+        contentType: 'application/gzip',
+      });
+      logger.info(
+        `Task ${taskId} metadata saved to GCS: gs://${this.bucketName}/${metadataObjectPath}`,
+      );
+
+      if (await fse.pathExists(workDir)) {
+        const entries = await fsPromises.readdir(workDir);
+        if (entries.length > 0) {
+          const tmpArchiveFile = join(tmpdir(), getTmpArchiveFilename(taskId));
+          try {
+            await tar.c(
+              {
+                gzip: true,
+                file: tmpArchiveFile,
+                cwd: workDir,
+                portable: true,
+              },
+              entries,
+            );
+
+            if (!(await fse.pathExists(tmpArchiveFile))) {
+              throw new Error(
+                `tar.c command failed to create ${tmpArchiveFile}`,
+              );
+            }
+
+            const workspaceFile = this.storage
+              .bucket(this.bucketName)
+              .file(workspaceObjectPath);
+            const sourceStream = createReadStream(tmpArchiveFile);
+            const destStream = workspaceFile.createWriteStream({
+              contentType: 'application/gzip',
+              resumable: true,
+            });
+
+            await new Promise<void>((resolve, reject) => {
+              sourceStream.on('error', (err) => {
+                logger.error(
+                  `Error in source stream for ${tmpArchiveFile}:`,
+                  err,
+                );
+                // Attempt to close destStream if source fails
+                if (!destStream.destroyed) {
+                  destStream.destroy(err);
+                }
+                reject(err);
+              });
+
+              destStream.on('error', (err) => {
+                logger.error(
+                  `Error in GCS dest stream for ${workspaceObjectPath}:`,
+                  err,
+                );
+                reject(err);
+              });
+
+              destStream.on('finish', () => {
+                logger.info(
+                  `GCS destStream finished for ${workspaceObjectPath}`,
+                );
+                resolve();
+              });
+
+              logger.info(
+                `Piping ${tmpArchiveFile} to GCS object ${workspaceObjectPath}`,
+              );
+              sourceStream.pipe(destStream);
+            });
+            logger.info(
+              `Task ${taskId} workspace saved to GCS: gs://${this.bucketName}/${workspaceObjectPath}`,
+            );
+          } catch (error) {
+            logger.error(
+              `Error during workspace save process for ${taskId}:`,
+              error,
+            );
+            throw error;
+          } finally {
+            logger.info(`Cleaning up temporary file: ${tmpArchiveFile}`);
+            try {
+              if (await fse.pathExists(tmpArchiveFile)) {
+                await fse.remove(tmpArchiveFile);
+                logger.info(
+                  `Successfully removed temporary file: ${tmpArchiveFile}`,
+                );
+              } else {
+                logger.warn(
+                  `Temporary file not found for cleanup: ${tmpArchiveFile}`,
+                );
+              }
+            } catch (removeError) {
+              logger.error(
+                `Error removing temporary file ${tmpArchiveFile}:`,
+                removeError,
+              );
+            }
+          }
+        } else {
+          logger.info(
+            `Workspace directory ${workDir} is empty, skipping workspace save for task ${taskId}.`,
+          );
+        }
+      } else {
+        logger.info(
+          `Workspace directory ${workDir} not found, skipping workspace save for task ${taskId}.`,
+        );
+      }
+    } catch (error) {
+      logger.error(`Failed to save task ${taskId} to GCS:`, error);
+      throw error;
+    }
+  }
+
+  async load(taskId: string): Promise<SDKTask | undefined> {
+    await this.ensureBucketInitialized();
+    const metadataObjectPath = this.getObjectPath(taskId, 'metadata');
+    const workspaceObjectPath = this.getObjectPath(taskId, 'workspace');
+
+    try {
+      const metadataFile = this.storage
+        .bucket(this.bucketName)
+        .file(metadataObjectPath);
+      const [metadataExists] = await metadataFile.exists();
+      if (!metadataExists) {
+        logger.info(`Task ${taskId} metadata not found in GCS.`);
+        return undefined;
+      }
+      const [compressedMetadata] = await metadataFile.download();
+      const jsonData = gunzipSync(compressedMetadata).toString();
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const loadedMetadata = JSON.parse(jsonData);
+      logger.info(`Task ${taskId} metadata loaded from GCS.`);
+
+      const persistedState = getPersistedState(loadedMetadata);
+      if (!persistedState) {
+        throw new Error(
+          `Loaded metadata for task ${taskId} is missing internal persisted state.`,
+        );
+      }
+      const agentSettings = persistedState._agentSettings;
+
+      const workDir = setTargetDir(agentSettings);
+      await fse.ensureDir(workDir);
+      const workspaceFile = this.storage
+        .bucket(this.bucketName)
+        .file(workspaceObjectPath);
+      const [workspaceExists] = await workspaceFile.exists();
+      if (workspaceExists) {
+        const tmpArchiveFile = join(tmpdir(), getTmpArchiveFilename(taskId));
+        try {
+          await workspaceFile.download({ destination: tmpArchiveFile });
+          await tar.x({ file: tmpArchiveFile, cwd: workDir });
+          logger.info(
+            `Task ${taskId} workspace restored from GCS to ${workDir}`,
+          );
+        } finally {
+          if (await fse.pathExists(tmpArchiveFile)) {
+            await fse.remove(tmpArchiveFile);
+          }
+        }
+      } else {
+        logger.info(`Task ${taskId} workspace archive not found in GCS.`);
+      }
+
+      return {
+        id: taskId,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+        contextId: loadedMetadata._contextId || uuidv4(),
+        kind: 'task',
+        status: {
+          state: persistedState._taskState,
+          timestamp: new Date().toISOString(),
+        },
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+        metadata: loadedMetadata,
+        history: [],
+        artifacts: [],
+      };
+    } catch (error) {
+      logger.error(`Failed to load task ${taskId} from GCS:`, error);
+      throw error;
+    }
+  }
+}
+
+export class NoOpTaskStore implements TaskStore {
+  constructor(private realStore: TaskStore) {}
+
+  async save(task: SDKTask): Promise<void> {
+    logger.info(`[NoOpTaskStore] save called for task ${task.id} - IGNORED`);
+    return Promise.resolve();
+  }
+
+  async load(taskId: string): Promise<SDKTask | undefined> {
+    logger.info(
+      `[NoOpTaskStore] load called for task ${taskId}, delegating to real store.`,
+    );
+    return this.realStore.load(taskId);
+  }
+}

packages/a2a-server/src/types.ts

@@ -0,0 +1,190 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type {
+  MCPServerStatus,
+  ToolConfirmationOutcome,
+} from '@google/gemini-cli-core';
+import type { TaskState } from '@a2a-js/sdk';
+
+// Interfaces and enums for the CoderAgent protocol.
+
+export enum CoderAgentEvent {
+  /**
+   * An event requesting one or more tool call confirmations.
+   */
+  ToolCallConfirmationEvent = 'tool-call-confirmation',
+  /**
+   * An event updating on the status of one or more tool calls.
+   */
+  ToolCallUpdateEvent = 'tool-call-update',
+  /**
+   * An event providing text updates on the task.
+   */
+  TextContentEvent = 'text-content',
+  /**
+   * An event that indicates a change in the task's execution state.
+   */
+  StateChangeEvent = 'state-change',
+  /**
+   * An user-sent event to initiate the agent.
+   */
+  StateAgentSettingsEvent = 'agent-settings',
+  /**
+   * An event that contains a thought from the agent.
+   */
+  ThoughtEvent = 'thought',
+  /**
+   * An event that contains citation from the agent.
+   */
+  CitationEvent = 'citation',
+}
+
+export interface AgentSettings {
+  kind: CoderAgentEvent.StateAgentSettingsEvent;
+  workspacePath: string;
+  autoExecute?: boolean;
+  isTrusted?: boolean;
+}
+
+export interface ToolCallConfirmation {
+  kind: CoderAgentEvent.ToolCallConfirmationEvent;
+}
+
+export interface ToolCallUpdate {
+  kind: CoderAgentEvent.ToolCallUpdateEvent;
+}
+
+export interface TextContent {
+  kind: CoderAgentEvent.TextContentEvent;
+}
+
+export interface StateChange {
+  kind: CoderAgentEvent.StateChangeEvent;
+}
+
+export interface Thought {
+  kind: CoderAgentEvent.ThoughtEvent;
+}
+
+export interface Citation {
+  kind: CoderAgentEvent.CitationEvent;
+}
+
+export type ThoughtSummary = {
+  subject: string;
+  description: string;
+};
+
+export interface ToolConfirmationResponse {
+  outcome: ToolConfirmationOutcome;
+  callId: string;
+}
+
+export type CoderAgentMessage =
+  | AgentSettings
+  | ToolCallConfirmation
+  | ToolCallUpdate
+  | TextContent
+  | StateChange
+  | Thought
+  | Citation;
+
+export interface TaskMetadata {
+  id: string;
+  contextId: string;
+  taskState: TaskState;
+  model: string;
+  mcpServers: Array<{
+    name: string;
+    status: MCPServerStatus;
+    tools: Array<{
+      name: string;
+      description: string;
+      parameterSchema: unknown;
+    }>;
+  }>;
+  availableTools: Array<{
+    name: string;
+    description: string;
+    parameterSchema: unknown;
+  }>;
+}
+
+export interface PersistedStateMetadata {
+  _agentSettings: AgentSettings;
+  _taskState: TaskState;
+}
+
+export type PersistedTaskMetadata = { [k: string]: unknown };
+
+export const METADATA_KEY = '__persistedState';
+
+function isAgentSettings(value: unknown): value is AgentSettings {
+  return (
+    typeof value === 'object' &&
+    value !== null &&
+    'kind' in value &&
+    value.kind === CoderAgentEvent.StateAgentSettingsEvent &&
+    'workspacePath' in value &&
+    typeof value.workspacePath === 'string'
+  );
+}
+
+function isPersistedStateMetadata(
+  value: unknown,
+): value is PersistedStateMetadata {
+  return (
+    typeof value === 'object' &&
+    value !== null &&
+    '_agentSettings' in value &&
+    '_taskState' in value &&
+    isAgentSettings(value._agentSettings)
+  );
+}
+
+export function getPersistedState(
+  metadata: PersistedTaskMetadata,
+): PersistedStateMetadata | undefined {
+  const state = metadata?.[METADATA_KEY];
+  if (isPersistedStateMetadata(state)) {
+    return state;
+  }
+  return undefined;
+}
+
+export function getContextIdFromMetadata(
+  metadata: PersistedTaskMetadata | undefined,
+): string | undefined {
+  if (!metadata) {
+    return undefined;
+  }
+  const contextId = metadata['_contextId'];
+  return typeof contextId === 'string' ? contextId : undefined;
+}
+
+export function getAgentSettingsFromMetadata(
+  metadata: PersistedTaskMetadata | undefined,
+): AgentSettings | undefined {
+  if (!metadata) {
+    return undefined;
+  }
+  const coderAgent = metadata['coderAgent'];
+  if (isAgentSettings(coderAgent)) {
+    return coderAgent;
+  }
+  return undefined;
+}
+
+export function setPersistedState(
+  metadata: PersistedTaskMetadata,
+  state: PersistedStateMetadata,
+): PersistedTaskMetadata {
+  return {
+    ...metadata,
+    [METADATA_KEY]: state,
+  };
+}

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

@@ -0,0 +1,51 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { Message } from '@a2a-js/sdk';
+import type { ExecutionEventBus } from '@a2a-js/sdk/server';
+import { v4 as uuidv4 } from 'uuid';
+
+import { CoderAgentEvent, type StateChange } from '../types.js';
+
+export async function pushTaskStateFailed(
+  error: unknown,
+  eventBus: ExecutionEventBus,
+  taskId: string,
+  contextId: string,
+) {
+  const errorMessage =
+    error instanceof Error ? error.message : 'Agent execution error';
+  const stateChange: StateChange = {
+    kind: CoderAgentEvent.StateChangeEvent,
+  };
+  eventBus.publish({
+    kind: 'status-update',
+    taskId,
+    contextId,
+    status: {
+      state: 'failed',
+      message: {
+        kind: 'message',
+        role: 'agent',
+        parts: [
+          {
+            kind: 'text',
+            text: errorMessage,
+          },
+        ],
+        messageId: uuidv4(),
+        taskId,
+        contextId,
+      } as Message,
+    },
+    final: true,
+    metadata: {
+      coderAgent: stateChange,
+      model: 'unknown',
+      error: errorMessage,
+    },
+  });
+}

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

@@ -0,0 +1,28 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import winston from 'winston';
+
+const logger = winston.createLogger({
+  level: 'info',
+  format: winston.format.combine(
+    // First, add a timestamp to the log info object
+    winston.format.timestamp({
+      format: 'YYYY-MM-DD HH:mm:ss.SSS A', // Custom timestamp format
+    }),
+    // Here we define the custom output format
+    winston.format.printf((info) => {
+      const { level, timestamp, message, ...rest } = info;
+      return (
+        `[${level.toUpperCase()}] ${timestamp} -- ${message}` +
+        `${Object.keys(rest).length > 0 ? `\n${JSON.stringify(rest, null, 2)}` : ''}`
+      ); // Only print ...rest if present
+    }),
+  ),
+  transports: [new winston.transports.Console()],
+});
+
+export { logger };

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

@@ -0,0 +1,233 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as path from 'node:path';
+import type {
+  Task as SDKTask,
+  TaskStatusUpdateEvent,
+  SendStreamingMessageSuccessResponse,
+} from '@a2a-js/sdk';
+import {
+  ApprovalMode,
+  DEFAULT_GEMINI_MODEL,
+  DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD,
+  GeminiClient,
+  HookSystem,
+  type MessageBus,
+  PolicyDecision,
+  tmpdir,
+  type Config,
+  type Storage,
+  NoopSandboxManager,
+  type ToolRegistry,
+  type SandboxManager,
+} from '@google/gemini-cli-core';
+import { createMockMessageBus } from '@google/gemini-cli-core/src/test-utils/mock-message-bus.js';
+import { expect, vi } from 'vitest';
+
+export function createMockConfig(
+  overrides: Partial<Config> = {},
+): Partial<Config> {
+  const tmpDir = tmpdir();
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const mockConfig = {
+    get config() {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      return this as unknown as Config;
+    },
+    get toolRegistry() {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      const config = this as unknown as Config;
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      return config.getToolRegistry?.() as unknown as ToolRegistry;
+    },
+    get messageBus() {
+      return (
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+        (this as unknown as Config).getMessageBus?.() as unknown as MessageBus
+      );
+    },
+    get geminiClient() {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      const config = this as unknown as Config;
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      return config.getGeminiClient?.() as unknown as GeminiClient;
+    },
+    getToolRegistry: vi.fn().mockReturnValue({
+      getTool: vi.fn(),
+      getAllToolNames: vi.fn().mockReturnValue([]),
+      getAllTools: vi.fn().mockReturnValue([]),
+      getToolsByServer: vi.fn().mockReturnValue([]),
+    }),
+    getApprovalMode: vi.fn().mockReturnValue(ApprovalMode.DEFAULT),
+    getIdeMode: vi.fn().mockReturnValue(false),
+    isInteractive: () => true,
+    getAllowedTools: vi.fn().mockReturnValue([]),
+    getWorkspaceContext: vi.fn().mockReturnValue({
+      isPathWithinWorkspace: () => true,
+    }),
+    getTargetDir: () => tmpDir,
+    getCheckpointingEnabled: vi.fn().mockReturnValue(false),
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    storage: {
+      getProjectTempDir: () => tmpDir,
+      getProjectTempCheckpointsDir: () => path.join(tmpDir, 'checkpoints'),
+    } as Storage,
+    getTruncateToolOutputThreshold: () =>
+      DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD,
+    getActiveModel: vi.fn().mockReturnValue(DEFAULT_GEMINI_MODEL),
+    getDebugMode: vi.fn().mockReturnValue(false),
+    getContentGeneratorConfig: vi.fn().mockReturnValue({ model: 'gemini-pro' }),
+    getModel: vi.fn().mockReturnValue('gemini-pro'),
+    getUsageStatisticsEnabled: vi.fn().mockReturnValue(false),
+    setFallbackModelHandler: vi.fn(),
+    initialize: vi.fn().mockResolvedValue(undefined),
+    getProxy: vi.fn().mockReturnValue(undefined),
+    getHistory: vi.fn().mockReturnValue([]),
+    getEmbeddingModel: vi.fn().mockReturnValue('text-embedding-004'),
+    getSessionId: vi.fn().mockReturnValue('test-session-id'),
+    getUserTier: vi.fn(),
+    getMessageBus: vi.fn(),
+    getPolicyEngine: vi.fn(),
+    getEnableExtensionReloading: vi.fn().mockReturnValue(false),
+    getEnableHooks: vi.fn().mockReturnValue(false),
+    getMcpClientManager: vi.fn().mockReturnValue({
+      getMcpServers: vi.fn().mockReturnValue({}),
+    }),
+    getTelemetryLogPromptsEnabled: vi.fn().mockReturnValue(false),
+    getTelemetryTracesEnabled: vi.fn().mockReturnValue(false),
+    getGitService: vi.fn(),
+    validatePathAccess: vi.fn().mockReturnValue(undefined),
+    getShellExecutionConfig: vi.fn().mockReturnValue({
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      sandboxManager: new NoopSandboxManager() as unknown as SandboxManager,
+      sanitizationConfig: {
+        allowedEnvironmentVariables: [],
+        blockedEnvironmentVariables: [],
+        enableEnvironmentVariableRedaction: false,
+      },
+    }),
+    isContextManagementEnabled: vi.fn().mockReturnValue(false),
+    getContextManagementConfig: vi.fn().mockReturnValue({ enabled: false }),
+    getExperimentalGemma: vi.fn().mockReturnValue(false),
+    ...overrides,
+  } as unknown as Config;
+
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  (mockConfig as unknown as { config: Config; promptId: string }).promptId =
+    'test-prompt-id';
+
+  mockConfig.getMessageBus = vi.fn().mockReturnValue(createMockMessageBus());
+  mockConfig.getHookSystem = vi
+    .fn()
+    .mockReturnValue(new HookSystem(mockConfig));
+
+  mockConfig.getGeminiClient = vi
+    .fn()
+    .mockReturnValue(new GeminiClient(mockConfig));
+
+  mockConfig.getPolicyEngine = vi.fn().mockReturnValue({
+    check: async () => {
+      const mode = mockConfig.getApprovalMode();
+      if (mode === ApprovalMode.YOLO) {
+        return { decision: PolicyDecision.ALLOW };
+      }
+      return { decision: PolicyDecision.ASK_USER };
+    },
+  });
+
+  return mockConfig;
+}
+
+export function createStreamMessageRequest(
+  text: string,
+  messageId: string,
+  taskId?: string,
+) {
+  const request: {
+    jsonrpc: string;
+    id: string;
+    method: string;
+    params: {
+      message: {
+        kind: string;
+        role: string;
+        parts: [{ kind: string; text: string }];
+        messageId: string;
+      };
+      metadata: {
+        coderAgent: {
+          kind: string;
+          workspacePath: string;
+        };
+      };
+      taskId?: string;
+    };
+  } = {
+    jsonrpc: '2.0',
+    id: '1',
+    method: 'message/stream',
+    params: {
+      message: {
+        kind: 'message',
+        role: 'user',
+        parts: [{ kind: 'text', text }],
+        messageId,
+      },
+      metadata: {
+        coderAgent: {
+          kind: 'agent-settings',
+          workspacePath: '/tmp',
+        },
+      },
+    },
+  };
+
+  if (taskId) {
+    request.params.taskId = taskId;
+  }
+
+  return request;
+}
+
+export function assertUniqueFinalEventIsLast(
+  events: SendStreamingMessageSuccessResponse[],
+) {
+  // Final event is input-required & final
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const finalEvent = events[events.length - 1].result as TaskStatusUpdateEvent;
+  expect(finalEvent.metadata?.['coderAgent']).toMatchObject({
+    kind: 'state-change',
+  });
+  expect(finalEvent.status?.state).toBe('input-required');
+  expect(finalEvent.final).toBe(true);
+
+  // There is only one event with final and its the last
+  expect(
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    events.filter((e) => (e.result as TaskStatusUpdateEvent).final).length,
+  ).toBe(1);
+  expect(
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+    events.findIndex((e) => (e.result as TaskStatusUpdateEvent).final),
+  ).toBe(events.length - 1);
+}
+
+export function assertTaskCreationAndWorkingStatus(
+  events: SendStreamingMessageSuccessResponse[],
+) {
+  // Initial task creation event
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const taskEvent = events[0].result as SDKTask;
+  expect(taskEvent.kind).toBe('task');
+  expect(taskEvent.status.state).toBe('submitted');
+
+  // Status update: working
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const workingEvent = events[1].result as TaskStatusUpdateEvent;
+  expect(workingEvent.kind).toBe('status-update');
+  expect(workingEvent.status.state).toBe('working');
+}

packages/a2a-server/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "lib": ["DOM", "DOM.Iterable", "ES2023"],
+    "composite": true,
+    "types": ["node", "vitest/globals"]
+  },
+  "include": ["index.ts", "src/**/*.ts", "src/**/*.json"],
+  "exclude": ["node_modules", "dist"]
+}

packages/a2a-server/vitest.config.ts

@@ -0,0 +1,46 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/// <reference types="vitest" />
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    include: ['**/*.{test,spec}.?(c|m)[jt]s?(x)'],
+    exclude: ['**/node_modules/**', '**/dist/**'],
+    globals: true,
+    reporters: ['default', 'junit'],
+    silent: true,
+    outputFile: {
+      junit: 'junit.xml',
+    },
+    coverage: {
+      enabled: true,
+      provider: 'v8',
+      reportsDirectory: './coverage',
+      include: ['src/**/*'],
+      reporter: [
+        ['text', { file: 'full-text-summary.txt' }],
+        'html',
+        'json',
+        'lcov',
+        'cobertura',
+        ['json-summary', { outputFile: 'coverage-summary.json' }],
+      ],
+    },
+    poolOptions: {
+      threads: {
+        minThreads: 8,
+        maxThreads: 16,
+      },
+    },
+    server: {
+      deps: {
+        inline: [/@google\/gemini-cli-core/],
+      },
+    },
+  },
+});

packages/cli/GEMINI.md

@@ -0,0 +1,28 @@
+## React & Ink (CLI UI)
+
+- **Side Effects**: Use reducers for complex state transitions; avoid `setState`
+  triggers in callbacks.
+- Always fix react-hooks/exhaustive-deps lint errors by adding the missing
+  dependencies.
+- **Shortcuts**: only define keyboard shortcuts in
+  `packages/cli/src/ui/key/keyBindings.ts`
+- Do not implement any logic performing custom string measurement or string
+  truncation. Use Ink layout instead leveraging ResizeObserver as needed. When
+  using `ResizeObserver`, prefer the `useCallback` ref pattern (as seen in
+  `MaxSizedBox.tsx`) to ensure size measurements are captured as soon as the
+  element is available, avoiding potential rendering timing issues.
+- Avoid prop drilling when at all possible.
+
+## Testing
+
+- **Utilities**: Use `renderWithProviders` and `waitFor` from
+  `packages/cli/src/test-utils/`.
+- **Snapshots**: Use `toMatchSnapshot()` to verify Ink output.
+- **SVG Snapshots**: Use `await expect(renderResult).toMatchSvgSnapshot()` for
+  UI components whenever colors or detailed visual layout matter. SVG snapshots
+  capture styling accurately. Make sure to await the `waitUntilReady()` of the
+  render result before asserting. After updating SVG snapshots, always examine
+  the resulting `.svg` files (e.g. by reading their content or visually
+  inspecting them) to ensure the render and colors actually look as expected and
+  don't just contain an error message.
+- **Mocks**: Use mocks as sparingly as possible.

packages/cli/examples/ask-user-dialog-demo.tsx

@@ -0,0 +1,102 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useState } from 'react';
+import { render, Box, Text } from 'ink';
+import { AskUserDialog } from '../src/ui/components/AskUserDialog.js';
+import { KeypressProvider } from '../src/ui/contexts/KeypressContext.js';
+import { QuestionType, type Question } from '@google/gemini-cli-core';
+
+const DEMO_QUESTIONS: Question[] = [
+  {
+    question: 'What type of project are you building?',
+    header: 'Project Type',
+    options: [
+      { label: 'Web Application', description: 'React, Next.js, or similar' },
+      { label: 'CLI Tool', description: 'Command-line interface with Node.js' },
+      { label: 'Library', description: 'NPM package or shared utility' },
+    ],
+    multiSelect: false,
+  },
+  {
+    question: 'Which features should be enabled?',
+    header: 'Features',
+    options: [
+      { label: 'TypeScript', description: 'Add static typing' },
+      { label: 'ESLint', description: 'Add linting and formatting' },
+      { label: 'Unit Tests', description: 'Add Vitest setup' },
+      { label: 'CI/CD', description: 'Add GitHub Actions' },
+    ],
+    multiSelect: true,
+  },
+  {
+    question: 'What is the project name?',
+    header: 'Name',
+    type: QuestionType.TEXT,
+    placeholder: 'my-awesome-project',
+  },
+  {
+    question: 'Initialize git repository?',
+    header: 'Git',
+    type: QuestionType.YESNO,
+  },
+];
+
+const Demo = () => {
+  const [result, setResult] = useState<null | { [key: string]: string }>(null);
+  const [cancelled, setCancelled] = useState(false);
+
+  if (cancelled) {
+    return (
+      <Box padding={1}>
+        <Text color="red">
+          Dialog was cancelled. Project initialization aborted.
+        </Text>
+      </Box>
+    );
+  }
+
+  if (result) {
+    return (
+      <Box
+        flexDirection="column"
+        padding={1}
+        borderStyle="single"
+        borderColor="green"
+      >
+        <Text bold color="green">
+          Success! Project Configuration:
+        </Text>
+        {DEMO_QUESTIONS.map((q, i) => (
+          <Box key={i} marginTop={1}>
+            <Text color="gray">{q.header}: </Text>
+            <Text>{result[i] || '(not answered)'}</Text>
+          </Box>
+        ))}
+        <Box marginTop={1}>
+          <Text color="dim">Press Ctrl+C to exit</Text>
+        </Box>
+      </Box>
+    );
+  }
+
+  return (
+    <KeypressProvider>
+      <Box padding={1} flexDirection="column">
+        <Text bold marginBottom={1}>
+          AskUserDialog Demo
+        </Text>
+        <AskUserDialog
+          questions={DEMO_QUESTIONS}
+          onSubmit={setResult}
+          onCancel={() => setCancelled(true)}
+        />
+      </Box>
+    </KeypressProvider>
+  );
+};
+
+render(<Demo />);

packages/cli/examples/scrollable-list-demo.tsx

@@ -0,0 +1,165 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useState, useEffect, useRef } from 'react';
+import { render, Box, Text, useInput, useStdout } from 'ink';
+import {
+  ScrollableList,
+  type ScrollableListRef,
+} from '../src/ui/components/shared/ScrollableList.js';
+import { ScrollProvider } from '../src/ui/contexts/ScrollProvider.js';
+import { MouseProvider } from '../src/ui/contexts/MouseContext.js';
+import { KeypressProvider } from '../src/ui/contexts/KeypressContext.js';
+import {
+  enableMouseEvents,
+  disableMouseEvents,
+} from '../src/ui/utils/mouse.js';
+
+interface Item {
+  id: string;
+  title: string;
+}
+
+const getLorem = (index: number) =>
+  Array(10)
+    .fill(null)
+    .map(() => 'lorem ipsum '.repeat((index % 3) + 1).trim())
+    .join('\n');
+
+const Demo = () => {
+  const { stdout } = useStdout();
+  const [size, setSize] = useState({
+    columns: stdout.columns,
+    rows: stdout.rows,
+  });
+
+  useEffect(() => {
+    const onResize = () => {
+      setSize({
+        columns: stdout.columns,
+        rows: stdout.rows,
+      });
+    };
+
+    stdout.on('resize', onResize);
+    return () => {
+      stdout.off('resize', onResize);
+    };
+  }, [stdout]);
+
+  const [items, setItems] = useState<Item[]>(() =>
+    Array.from({ length: 1000 }, (_, i) => ({
+      id: String(i),
+      title: `Item ${i + 1}`,
+    })),
+  );
+
+  const listRef = useRef<ScrollableListRef<Item>>(null);
+
+  useInput((input, key) => {
+    if (input === 'a' || input === 'A') {
+      setItems((prev) => [
+        ...prev,
+        { id: String(prev.length), title: `Item ${prev.length + 1}` },
+      ]);
+    }
+    if ((input === 'e' || input === 'E') && !key.ctrl) {
+      setItems((prev) => {
+        if (prev.length === 0) return prev;
+        const lastIndex = prev.length - 1;
+        const lastItem = prev[lastIndex]!;
+        const newItem = { ...lastItem, title: lastItem.title + 'e' };
+        return [...prev.slice(0, lastIndex), newItem];
+      });
+    }
+    if (key.ctrl && input === 'e') {
+      listRef.current?.scrollToEnd();
+    }
+    // Let Ink handle Ctrl+C via exitOnCtrlC (default true) or handle explicitly if needed.
+    // For alternate buffer, explicit handling is often safer for cleanup.
+    if (key.escape || (key.ctrl && input === 'c')) {
+      process.exit(0);
+    }
+  });
+
+  return (
+    <MouseProvider mouseEventsEnabled={true}>
+      <KeypressProvider>
+        <ScrollProvider>
+          <Box
+            flexDirection="column"
+            width={size.columns}
+            height={size.rows - 1}
+            padding={1}
+          >
+            <Text>
+              Press &apos;A&apos; to add an item. Press &apos;E&apos; to edit
+              last item. Press &apos;Ctrl+E&apos; to scroll to end. Press
+              &apos;Esc&apos; to exit. Mouse wheel or Shift+Up/Down to scroll.
+            </Text>
+            <Box flexGrow={1} borderStyle="round" borderColor="cyan">
+              <ScrollableList
+                ref={listRef}
+                data={items}
+                renderItem={({ item, index }) => (
+                  <Box flexDirection="column" paddingBottom={2}>
+                    <Box
+                      sticky
+                      flexDirection="column"
+                      width={size.columns - 2}
+                      opaque
+                      stickyChildren={
+                        <Box
+                          flexDirection="column"
+                          width={size.columns - 2}
+                          opaque
+                        >
+                          <Text>{item.title}</Text>
+                          <Box
+                            borderStyle="single"
+                            borderTop={true}
+                            borderBottom={false}
+                            borderLeft={false}
+                            borderRight={false}
+                            borderColor="gray"
+                          />
+                        </Box>
+                      }
+                    >
+                      <Text>{item.title}</Text>
+                    </Box>
+                    <Text color="gray">{getLorem(index)}</Text>
+                  </Box>
+                )}
+                estimatedItemHeight={() => 14}
+                keyExtractor={(item) => item.id}
+                hasFocus={true}
+                initialScrollIndex={Number.MAX_SAFE_INTEGER}
+                initialScrollOffsetInIndex={Number.MAX_SAFE_INTEGER}
+              />
+            </Box>
+            <Text>Count: {items.length}</Text>
+          </Box>
+        </ScrollProvider>
+      </KeypressProvider>
+    </MouseProvider>
+  );
+};
+
+// Enable mouse reporting before rendering
+enableMouseEvents();
+
+// Ensure cleanup happens on exit
+process.on('exit', () => {
+  disableMouseEvents();
+});
+
+// Handle SIGINT explicitly to ensure cleanup runs if Ink doesn't catch it in time
+process.on('SIGINT', () => {
+  process.exit(0);
+});
+
+render(<Demo />, { alternateBuffer: true });

packages/cli/index.ts

@@ -0,0 +1,193 @@
+#!/usr/bin/env node
+
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { spawn } from 'node:child_process';
+import os from 'node:os';
+import v8 from 'node:v8';
+import {
+  RELAUNCH_EXIT_CODE,
+  getSpawnConfig,
+  getScriptArgs,
+} from './src/utils/processUtils.js';
+
+// --- Global Entry Point ---
+
+// Suppress known race condition error in node-pty on Windows and Linux
+// Tracking bug: https://github.com/microsoft/node-pty/issues/827
+process.on('uncaughtException', (error) => {
+  if (error instanceof Error) {
+    const message = error.message || '';
+    const isPtyResizeError =
+      message === 'Cannot resize a pty that has already exited';
+    const isEbadfError =
+      message.includes('EBADF') ||
+      (error as { code?: string }).code === 'EBADF';
+    const isFromNodePty =
+      error.stack?.includes('node-pty') || error.stack?.includes('PtyResize');
+
+    if ((isPtyResizeError || isEbadfError) && isFromNodePty) {
+      // This error happens with node-pty when resizing a pty that has just exited.
+      // It is a race condition in node-pty that we cannot prevent, so we silence it.
+      return;
+    }
+  }
+
+  // For other errors, we rely on the default behavior, but since we attached a listener,
+  // we must manually replicate it.
+  if (error instanceof Error) {
+    process.stderr.write(error.stack + '\n');
+  } else {
+    process.stderr.write(String(error) + '\n');
+  }
+  process.exit(1);
+});
+
+async function getMemoryNodeArgs(): Promise<string[]> {
+  let autoConfigureMemory = true;
+  try {
+    const { readFileSync } = await import('node:fs');
+    const { join } = await import('node:path');
+    // Respect GEMINI_CLI_HOME environment variable, falling back to os.homedir()
+    const baseDir =
+      process.env['GEMINI_CLI_HOME'] || join(os.homedir(), '.gemini');
+    const settingsPath = join(baseDir, 'settings.json');
+    const rawSettings = readFileSync(settingsPath, 'utf8');
+    const settings = JSON.parse(rawSettings);
+    if (settings?.advanced?.autoConfigureMemory === false) {
+      autoConfigureMemory = false;
+    }
+  } catch {
+    // ignore
+  }
+
+  if (autoConfigureMemory) {
+    const totalMemoryMB = os.totalmem() / (1024 * 1024);
+    const heapStats = v8.getHeapStatistics();
+    const currentMaxOldSpaceSizeMb = Math.floor(
+      heapStats.heap_size_limit / 1024 / 1024,
+    );
+    const targetMaxOldSpaceSizeInMB = Math.floor(totalMemoryMB * 0.5);
+
+    if (targetMaxOldSpaceSizeInMB > currentMaxOldSpaceSizeMb) {
+      return [`--max-old-space-size=${targetMaxOldSpaceSizeInMB}`];
+    }
+  }
+
+  return [];
+}
+
+async function run() {
+  if (!process.env['GEMINI_CLI_NO_RELAUNCH'] && !process.env['SANDBOX']) {
+    // --- Lightweight Parent Process / Daemon ---
+    // We avoid importing heavy dependencies here to save ~1.5s of startup time.
+
+    const scriptArgs = getScriptArgs();
+    const memoryArgs = await getMemoryNodeArgs();
+    const { spawnArgs, env: newEnv } = getSpawnConfig(memoryArgs, scriptArgs);
+
+    let latestAdminSettings: unknown = undefined;
+
+    // Prevent the parent process from exiting prematurely on signals.
+    // The child process will receive the same signals and handle its own cleanup.
+    for (const sig of ['SIGINT', 'SIGTERM', 'SIGHUP']) {
+      process.on(sig as NodeJS.Signals, () => {});
+    }
+
+    const runner = () => {
+      process.stdin.pause();
+
+      const child = spawn(process.execPath, spawnArgs, {
+        stdio: ['inherit', 'inherit', 'inherit', 'ipc'],
+        env: newEnv,
+      });
+
+      if (latestAdminSettings) {
+        child.send({ type: 'admin-settings', settings: latestAdminSettings });
+      }
+
+      child.on('message', (msg: { type?: string; settings?: unknown }) => {
+        if (msg.type === 'admin-settings-update' && msg.settings) {
+          latestAdminSettings = msg.settings;
+        }
+      });
+
+      return new Promise<number>((resolve) => {
+        child.on('error', (err) => {
+          process.stderr.write(
+            'Error: Failed to start child process: ' + err.message + '\n',
+          );
+          resolve(1);
+        });
+        child.on('close', (code) => {
+          process.stdin.resume();
+          resolve(code ?? 1);
+        });
+      });
+    };
+
+    while (true) {
+      try {
+        const exitCode = await runner();
+        if (process.platform === 'android' || exitCode !== RELAUNCH_EXIT_CODE) {
+          process.exit(exitCode);
+        }
+      } catch (error: unknown) {
+        process.stdin.resume();
+        process.stderr.write(
+          `Fatal error: Failed to relaunch the CLI process.\n${error instanceof Error ? (error.stack ?? error.message) : String(error)}\n`,
+        );
+        process.exit(1);
+      }
+    }
+  } else {
+    // --- Heavy Child Process ---
+    // Now we can safely import everything.
+    const { main } = await import('./src/gemini.js');
+    const { FatalError, writeToStderr } = await import(
+      '@google/gemini-cli-core'
+    );
+    const { runExitCleanup } = await import('./src/utils/cleanup.js');
+
+    main().catch(async (error: unknown) => {
+      // Set a timeout to force exit if cleanup hangs
+      const cleanupTimeout = setTimeout(() => {
+        writeToStderr('Cleanup timed out, forcing exit...\n');
+        process.exit(1);
+      }, 5000);
+
+      try {
+        await runExitCleanup();
+      } catch (cleanupError: unknown) {
+        writeToStderr(
+          `Error during final cleanup: ${cleanupError instanceof Error ? cleanupError.message : String(cleanupError)}\n`,
+        );
+      } finally {
+        clearTimeout(cleanupTimeout);
+      }
+
+      if (error instanceof FatalError) {
+        let errorMessage = error.message;
+        if (!process.env['NO_COLOR']) {
+          errorMessage = `\x1b[31m${errorMessage}\x1b[0m`;
+        }
+        writeToStderr(errorMessage + '\n');
+        process.exit(error.exitCode);
+      }
+
+      writeToStderr('An unexpected critical error occurred:');
+      if (error instanceof Error) {
+        writeToStderr(error.stack + '\n');
+      } else {
+        writeToStderr(String(error) + '\n');
+      }
+      process.exit(1);
+    });
+  }
+}
+
+run();

packages/cli/package.json

@@ -0,0 +1,91 @@
+{
+  "name": "@google/gemini-cli",
+  "version": "0.52.0-nightly.20260707.g27a3da3e8",
+  "description": "Gemini CLI",
+  "license": "Apache-2.0",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/google-gemini/gemini-cli.git"
+  },
+  "type": "module",
+  "main": "dist/index.js",
+  "bin": {
+    "gemini": "dist/index.js"
+  },
+  "scripts": {
+    "build": "node ../../scripts/build_package.js",
+    "start": "node dist/index.js",
+    "debug": "node --inspect-brk dist/index.js",
+    "lint": "eslint . --ext .ts,.tsx",
+    "format": "prettier --write .",
+    "test": "vitest run",
+    "test:ci": "vitest run",
+    "posttest": "npm run build",
+    "typecheck": "tsc --noEmit"
+  },
+  "files": [
+    "dist"
+  ],
+  "config": {
+    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.52.0-nightly.20260707.g27a3da3e8"
+  },
+  "dependencies": {
+    "@agentclientprotocol/sdk": "0.16.1",
+    "@google/gemini-cli-core": "file:../core",
+    "@google/genai": "1.30.0",
+    "@iarna/toml": "2.2.5",
+    "@modelcontextprotocol/sdk": "1.23.0",
+    "ansi-escapes": "7.3.0",
+    "ansi-regex": "6.2.2",
+    "chalk": "4.1.2",
+    "cli-spinners": "2.9.2",
+    "clipboardy": "5.2.0",
+    "color-convert": "2.0.1",
+    "command-exists": "1.2.9",
+    "comment-json": "4.2.5",
+    "diff": "8.0.3",
+    "dotenv": "17.1.0",
+    "extract-zip": "2.0.1",
+    "fzf": "0.5.2",
+    "glob": "12.0.0",
+    "highlight.js": "11.11.1",
+    "ink": "npm:@jrichman/ink@6.6.9",
+    "ink-gradient": "3.0.0",
+    "ink-spinner": "5.0.0",
+    "latest-version": "9.0.0",
+    "lowlight": "3.3.0",
+    "mnemonist": "0.40.3",
+    "open": "10.1.2",
+    "prompts": "2.4.2",
+    "proper-lockfile": "4.1.2",
+    "react": "19.2.4",
+    "shell-quote": "1.8.3",
+    "simple-git": "3.28.0",
+    "string-width": "8.1.0",
+    "strip-ansi": "7.1.0",
+    "strip-json-comments": "3.1.1",
+    "tar": "7.5.8",
+    "tinygradient": "1.1.5",
+    "undici": "7.10.0",
+    "ws": "8.16.0",
+    "yargs": "17.7.2",
+    "zod": "3.25.76"
+  },
+  "devDependencies": {
+    "@google/gemini-cli-test-utils": "file:../test-utils",
+    "@types/command-exists": "1.2.3",
+    "@types/hast": "3.0.4",
+    "@types/node": "20.11.24",
+    "@types/react": "19.2.0",
+    "@types/semver": "7.7.0",
+    "@types/shell-quote": "1.7.5",
+    "@types/ws": "8.5.10",
+    "@types/yargs": "17.0.32",
+    "@xterm/headless": "5.5.0",
+    "typescript": "5.8.3",
+    "vitest": "3.2.4"
+  },
+  "engines": {
+    "node": ">=20"
+  }
+}

packages/cli/src/__snapshots__/nonInteractiveCli.test.ts.snap

@@ -0,0 +1,35 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`runNonInteractive > should emit appropriate error event in streaming JSON mode: 'loop detected' 1`] = `
+"{"type":"init","timestamp":"<TIMESTAMP>","session_id":"test-session-id","model":"test-model"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"user","content":"Loop test"}
+{"type":"error","timestamp":"<TIMESTAMP>","severity":"warning","message":"Loop detected, stopping execution"}
+{"type":"result","timestamp":"<TIMESTAMP>","status":"success","stats":{"total_tokens":0,"input_tokens":0,"output_tokens":0,"cached":0,"input":0,"duration_ms":<DURATION>,"tool_calls":0,"models":{}}}
+"
+`;
+
+exports[`runNonInteractive > should emit appropriate error event in streaming JSON mode: 'max session turns' 1`] = `
+"{"type":"init","timestamp":"<TIMESTAMP>","session_id":"test-session-id","model":"test-model"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"user","content":"Max turns test"}
+{"type":"error","timestamp":"<TIMESTAMP>","severity":"error","message":"Maximum session turns exceeded"}
+{"type":"result","timestamp":"<TIMESTAMP>","status":"success","stats":{"total_tokens":0,"input_tokens":0,"output_tokens":0,"cached":0,"input":0,"duration_ms":<DURATION>,"tool_calls":0,"models":{}}}
+"
+`;
+
+exports[`runNonInteractive > should emit appropriate events for streaming JSON output 1`] = `
+"{"type":"init","timestamp":"<TIMESTAMP>","session_id":"test-session-id","model":"test-model"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"user","content":"Stream test"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"assistant","content":"Thinking...","delta":true}
+{"type":"tool_use","timestamp":"<TIMESTAMP>","tool_name":"testTool","tool_id":"tool-1","parameters":{"arg1":"value1"}}
+{"type":"tool_result","timestamp":"<TIMESTAMP>","tool_id":"tool-1","status":"success","output":"Tool executed successfully"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"assistant","content":"Final answer","delta":true}
+{"type":"result","timestamp":"<TIMESTAMP>","status":"success","stats":{"total_tokens":0,"input_tokens":0,"output_tokens":0,"cached":0,"input":0,"duration_ms":<DURATION>,"tool_calls":0,"models":{}}}
+"
+`;
+
+exports[`runNonInteractive > should write a single newline between sequential text outputs from the model 1`] = `
+"Use mock tool
+Use mock tool again
+Finished.
+"
+`;

packages/cli/src/__snapshots__/nonInteractiveCliAgentSession.test.ts.snap

@@ -0,0 +1,35 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`runNonInteractive > should emit appropriate error event in streaming JSON mode: 'loop detected' 1`] = `
+"{"type":"init","timestamp":"<TIMESTAMP>","session_id":"test-session-id","model":"test-model"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"user","content":"Loop test"}
+{"type":"error","timestamp":"<TIMESTAMP>","severity":"warning","message":"Loop detected, stopping execution"}
+{"type":"result","timestamp":"<TIMESTAMP>","status":"success","stats":{"total_tokens":0,"input_tokens":0,"output_tokens":0,"cached":0,"input":0,"duration_ms":<DURATION>,"tool_calls":0,"models":{}}}
+"
+`;
+
+exports[`runNonInteractive > should emit appropriate error event in streaming JSON mode: 'max session turns' 1`] = `
+"{"type":"init","timestamp":"<TIMESTAMP>","session_id":"test-session-id","model":"test-model"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"user","content":"Max turns test"}
+{"type":"error","timestamp":"<TIMESTAMP>","severity":"error","message":"Maximum session turns exceeded"}
+{"type":"result","timestamp":"<TIMESTAMP>","status":"success","stats":{"total_tokens":0,"input_tokens":0,"output_tokens":0,"cached":0,"input":0,"duration_ms":<DURATION>,"tool_calls":0,"models":{}}}
+"
+`;
+
+exports[`runNonInteractive > should emit appropriate events for streaming JSON output 1`] = `
+"{"type":"init","timestamp":"<TIMESTAMP>","session_id":"test-session-id","model":"test-model"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"user","content":"Stream test"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"assistant","content":"Thinking...","delta":true}
+{"type":"tool_use","timestamp":"<TIMESTAMP>","tool_name":"testTool","tool_id":"tool-1","parameters":{"arg1":"value1"}}
+{"type":"tool_result","timestamp":"<TIMESTAMP>","tool_id":"tool-1","status":"success","output":"Tool executed successfully"}
+{"type":"message","timestamp":"<TIMESTAMP>","role":"assistant","content":"Final answer","delta":true}
+{"type":"result","timestamp":"<TIMESTAMP>","status":"success","stats":{"total_tokens":0,"input_tokens":0,"output_tokens":0,"cached":0,"input":0,"duration_ms":<DURATION>,"tool_calls":0,"models":{}}}
+"
+`;
+
+exports[`runNonInteractive > should write a single newline between sequential text outputs from the model 1`] = `
+"Use mock tool
+Use mock tool again
+Finished.
+"
+`;

packages/cli/src/acp/README.md

@@ -0,0 +1,81 @@
+# Agent Client Protocol (ACP) Implementation
+
+This directory contains the implementation of the Agent Client Protocol (ACP)
+for the Gemini CLI. The ACP allows external clients (like IDE extensions) to
+communicate with the Gemini CLI agent over a structured JSON-RPC based protocol.
+
+## Directory Structure
+
+Following Phase 1 of the modularization refactor, the ACP client is organized
+into the following specialized modules, all sharing the `acp` prefix for
+consistency:
+
+- **[acpStdioTransport.ts](./acpStdioTransport.ts)**: Handles raw I/O. It sets
+  up the Web streams for standard input/output and creates the
+  `AgentSideConnection` using line-delimited JSON (ndjson).
+- **[acpRpcDispatcher.ts](./acpRpcDispatcher.ts)**: Contains the `GeminiAgent`
+  class. This is the main entry point for incoming JSON-RPC messages. It
+  implements the protocol methods and delegates session-specific work to the
+  manager and individual sessions.
+- **[acpSessionManager.ts](./acpSessionManager.ts)**: Manages multi-session
+  state. It handles session creation (`newSession`), loading (`loadSession`),
+  and configuration, isolating session state from the RPC routing.
+- **[acpSession.ts](./acpSession.ts)**: Manages individual active chat sessions.
+  It handles prompt execution, `@path` file resolution, tool execution, command
+  interception, and streaming updates back to the client.
+- **[acpUtils.ts](./acpUtils.ts)**: Contains shared helper functions, type
+  mappers (e.g., mapping internal tool kinds to ACP kinds), and Zod schemas used
+  across the modules.
+- **[acpErrors.ts](./acpErrors.ts)**: Centralized error handling and mapping to
+  ACP-compliant error codes.
+- **[acpCommandHandler.ts](./acpCommandHandler.ts)**: Handles interception and
+  execution of slash commands (e.g., `/memory`, `/init`) sent via ACP prompts.
+- **[acpFileSystemService.ts](./acpFileSystemService.ts)**: Provides access to
+  the file system restricted by the workspace boundaries and permissions.
+
+## Development Instructions
+
+### Running Tests
+
+Tests are co-located with the source files:
+
+- `acpRpcDispatcher.test.ts`: Tests for initialization, authentication, and
+  handler delegation.
+- `acpSessionManager.test.ts`: Tests for session lifecycle and configuration.
+- `acpSession.test.ts`: Tests for prompt loops, tool execution, and @path
+  resolution.
+- `acpResume.test.ts`: Integration tests for loading/resuming sessions.
+
+To run specific tests, use Vitest with the workspace filter:
+
+```bash
+# General pattern
+npm test -w @google/gemini-cli -- src/acp/<test-file-name>.ts
+
+# Example
+npm test -w @google/gemini-cli -- src/acp/acpRpcDispatcher.test.ts
+```
+
+Note: You may need to ensure your environment has Node available. If running in
+a restricted environment, try sourcing NVM first:
+
+```bash
+source ~/.nvm/nvm.sh && nvm use default && npm test -w @google/gemini-cli -- src/acp/acpSession.test.ts
+```
+
+### Adding New Features
+
+- **New RPC Method**: Add the method to `GeminiAgent` in `acpRpcDispatcher.ts`
+  and register it in the `AgentSideConnection` setup if necessary.
+- **Session State**: If a feature requires storing state across turns within a
+  session, add it to the `Session` class in `acpSession.ts`.
+- **Protocol Helpers**: Add any new mapping or serialization logic to
+  `acpUtils.ts`.
+
+### Coding Conventions
+
+- **Imports**: Use specific imports and do not import across package boundaries
+  using relative paths.
+- **License Headers**: All new files must include the Apache-2.0 license header.
+- **Type Safety**: Avoid using `any` assertions. Use Zod schemas to validate
+  untrusted input from the protocol.

packages/cli/src/acp/acpCommandHandler.test.ts

@@ -0,0 +1,35 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { CommandHandler } from './acpCommandHandler.js';
+import { describe, it, expect } from 'vitest';
+
+describe('CommandHandler', () => {
+  it('parses commands correctly', () => {
+    const handler = new CommandHandler();
+    // @ts-expect-error - testing private method
+    const parse = (query: string) => handler.parseSlashCommand(query);
+
+    const memShow = parse('/memory show');
+    expect(memShow.commandToExecute?.name).toBe('memory show');
+    expect(memShow.args).toBe('');
+
+    const memList = parse('/memory list');
+    expect(memList.commandToExecute?.name).toBe('memory list');
+
+    const extList = parse('/extensions list');
+    expect(extList.commandToExecute?.name).toBe('extensions list');
+
+    const init = parse('/init');
+    expect(init.commandToExecute?.name).toBe('init');
+
+    const about = parse('/about');
+    expect(about.commandToExecute?.name).toBe('about');
+
+    const help = parse('/help');
+    expect(help.commandToExecute?.name).toBe('help');
+  });
+});

packages/cli/src/acp/acpCommandHandler.ts

@@ -0,0 +1,138 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { Command, CommandContext } from './commands/types.js';
+import { CommandRegistry } from './commands/commandRegistry.js';
+import { MemoryCommand } from './commands/memory.js';
+import { ExtensionsCommand } from './commands/extensions.js';
+import { InitCommand } from './commands/init.js';
+import { RestoreCommand } from './commands/restore.js';
+import { AboutCommand } from './commands/about.js';
+import { HelpCommand } from './commands/help.js';
+
+export class CommandHandler {
+  private registry: CommandRegistry;
+
+  constructor() {
+    this.registry = CommandHandler.createRegistry();
+  }
+
+  private static createRegistry(): CommandRegistry {
+    const registry = new CommandRegistry();
+    registry.register(new MemoryCommand());
+    registry.register(new ExtensionsCommand());
+    registry.register(new InitCommand());
+    registry.register(new RestoreCommand());
+    registry.register(new AboutCommand());
+    registry.register(new HelpCommand(registry));
+    return registry;
+  }
+
+  getAvailableCommands(): Array<{ name: string; description: string }> {
+    return this.registry.getAllCommands().map((cmd) => ({
+      name: cmd.name,
+      description: cmd.description,
+    }));
+  }
+
+  /**
+   * Parses and executes a command string if it matches a registered command.
+   * Returns true if a command was handled, false otherwise.
+   */
+  async handleCommand(
+    commandText: string,
+    context: CommandContext,
+  ): Promise<boolean> {
+    const { commandToExecute, args } = this.parseSlashCommand(commandText);
+
+    if (commandToExecute) {
+      await this.runCommand(commandToExecute, args, context);
+      return true;
+    }
+
+    return false;
+  }
+
+  private async runCommand(
+    commandToExecute: Command,
+    args: string,
+    context: CommandContext,
+  ): Promise<void> {
+    try {
+      const result = await commandToExecute.execute(
+        context,
+        args ? args.split(/\s+/) : [],
+      );
+
+      let messageContent = '';
+      if (typeof result.data === 'string') {
+        messageContent = result.data;
+      } else if (
+        typeof result.data === 'object' &&
+        result.data !== null &&
+        'content' in result.data
+      ) {
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion, @typescript-eslint/no-explicit-any
+        messageContent = (result.data as Record<string, any>)[
+          'content'
+        ] as string;
+      } else {
+        messageContent = JSON.stringify(result.data, null, 2);
+      }
+
+      await context.sendMessage(messageContent);
+    } catch (error) {
+      const errorMessage =
+        error instanceof Error ? error.message : String(error);
+      await context.sendMessage(`Error: ${errorMessage}`);
+    }
+  }
+
+  /**
+   * Parses a raw slash command string into its matching headless command and arguments.
+   * Mirrors `packages/cli/src/utils/commands.ts` logic.
+   */
+  private parseSlashCommand(query: string): {
+    commandToExecute: Command | undefined;
+    args: string;
+  } {
+    const trimmed = query.trim();
+    const parts = trimmed.substring(1).trim().split(/\s+/);
+    const commandPath = parts.filter((p) => p);
+
+    let currentCommands = this.registry.getAllCommands();
+    let commandToExecute: Command | undefined;
+    let pathIndex = 0;
+
+    for (const part of commandPath) {
+      const foundCommand = currentCommands.find((cmd) => {
+        const expectedName = commandPath.slice(0, pathIndex + 1).join(' ');
+        return (
+          cmd.name === part ||
+          cmd.name === expectedName ||
+          cmd.aliases?.includes(part) ||
+          cmd.aliases?.includes(expectedName)
+        );
+      });
+
+      if (foundCommand) {
+        commandToExecute = foundCommand;
+        pathIndex++;
+        if (foundCommand.subCommands) {
+          currentCommands = foundCommand.subCommands;
+        } else {
+          break;
+        }
+      } else {
+        break;
+      }
+    }
+
+    const args = parts.slice(pathIndex).join(' ');
+
+    return { commandToExecute, args };
+  }
+}

packages/cli/src/acp/acpErrors.test.ts

@@ -0,0 +1,45 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { getAcpErrorMessage } from './acpErrors.js';
+
+describe('getAcpErrorMessage', () => {
+  it('should return plain error message', () => {
+    expect(getAcpErrorMessage(new Error('plain error'))).toBe('plain error');
+  });
+
+  it('should parse simple JSON error response', () => {
+    const json = JSON.stringify({ error: { message: 'json error' } });
+    expect(getAcpErrorMessage(new Error(json))).toBe('json error');
+  });
+
+  it('should parse double-encoded JSON error response', () => {
+    const innerJson = JSON.stringify({ error: { message: 'nested error' } });
+    const outerJson = JSON.stringify({ error: { message: innerJson } });
+    expect(getAcpErrorMessage(new Error(outerJson))).toBe('nested error');
+  });
+
+  it('should parse array-style JSON error response', () => {
+    const json = JSON.stringify([{ error: { message: 'array error' } }]);
+    expect(getAcpErrorMessage(new Error(json))).toBe('array error');
+  });
+
+  it('should parse JSON with top-level message field', () => {
+    const json = JSON.stringify({ message: 'top-level message' });
+    expect(getAcpErrorMessage(new Error(json))).toBe('top-level message');
+  });
+
+  it('should handle JSON with trailing newline', () => {
+    const json = JSON.stringify({ error: { message: 'newline error' } }) + '\n';
+    expect(getAcpErrorMessage(new Error(json))).toBe('newline error');
+  });
+
+  it('should return original message if JSON parsing fails', () => {
+    const invalidJson = '{ not-json }';
+    expect(getAcpErrorMessage(new Error(invalidJson))).toBe(invalidJson);
+  });
+});

packages/cli/src/acp/acpErrors.ts

@@ -0,0 +1,44 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { getErrorMessage as getCoreErrorMessage } from '@google/gemini-cli-core';
+
+/**
+ * Extracts a human-readable error message specifically for ACP (IDE) clients.
+ * This function recursively parses JSON error blobs that are common in
+ * Google API responses but ugly to display in an IDE's UI.
+ */
+export function getAcpErrorMessage(error: unknown): string {
+  const coreMessage = getCoreErrorMessage(error);
+  return extractRecursiveMessage(coreMessage);
+}
+
+function extractRecursiveMessage(input: string): string {
+  const trimmed = input.trim();
+
+  // Attempt to parse JSON error responses (common in Google API errors)
+  if (
+    (trimmed.startsWith('{') && trimmed.endsWith('}')) ||
+    (trimmed.startsWith('[') && trimmed.endsWith(']'))
+  ) {
+    try {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const parsed = JSON.parse(trimmed);
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const next =
+        parsed?.error?.message ||
+        parsed?.[0]?.error?.message ||
+        parsed?.message;
+
+      if (next && typeof next === 'string' && next !== input) {
+        return extractRecursiveMessage(next);
+      }
+    } catch {
+      // Fall back to original string if parsing fails
+    }
+  }
+  return input;
+}

packages/cli/src/acp/acpFileSystemService.test.ts

@@ -0,0 +1,236 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  afterEach,
+  type Mocked,
+} from 'vitest';
+import { AcpFileSystemService } from './acpFileSystemService.js';
+import type { AgentSideConnection } from '@agentclientprotocol/sdk';
+import type { FileSystemService } from '@google/gemini-cli-core';
+import os from 'node:os';
+
+vi.mock('node:os', () => ({
+  default: {
+    homedir: vi.fn(),
+  },
+}));
+
+describe('AcpFileSystemService', () => {
+  let mockConnection: Mocked<AgentSideConnection>;
+  let mockFallback: Mocked<FileSystemService>;
+  let service: AcpFileSystemService;
+
+  beforeEach(() => {
+    mockConnection = {
+      requestPermission: vi.fn(),
+      sessionUpdate: vi.fn(),
+      writeTextFile: vi.fn(),
+      readTextFile: vi.fn(),
+    } as unknown as Mocked<AgentSideConnection>;
+    mockFallback = {
+      readTextFile: vi.fn(),
+      writeTextFile: vi.fn(),
+    };
+    vi.mocked(os.homedir).mockReturnValue('/home/user');
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  describe('readTextFile', () => {
+    it.each([
+      {
+        capability: true,
+        path: '/path/to/file',
+        desc: 'connection if capability exists and file is inside root',
+        setup: () => {
+          mockConnection.readTextFile.mockResolvedValue({ content: 'content' });
+        },
+        verify: () => {
+          expect(mockConnection.readTextFile).toHaveBeenCalledWith({
+            path: '/path/to/file',
+            sessionId: 'session-1',
+          });
+          expect(mockFallback.readTextFile).not.toHaveBeenCalled();
+        },
+      },
+      {
+        capability: false,
+        path: '/path/to/file',
+        desc: 'fallback if capability missing',
+        setup: () => {
+          mockFallback.readTextFile.mockResolvedValue('content');
+        },
+        verify: () => {
+          expect(mockFallback.readTextFile).toHaveBeenCalledWith(
+            '/path/to/file',
+          );
+          expect(mockConnection.readTextFile).not.toHaveBeenCalled();
+        },
+      },
+      {
+        capability: true,
+        path: '/outside/file',
+        desc: 'fallback if capability exists but file is outside root',
+        setup: () => {
+          mockFallback.readTextFile.mockResolvedValue('content');
+        },
+        verify: () => {
+          expect(mockFallback.readTextFile).toHaveBeenCalledWith(
+            '/outside/file',
+          );
+          expect(mockConnection.readTextFile).not.toHaveBeenCalled();
+        },
+      },
+      {
+        capability: true,
+        path: '/home/user/.gemini/tmp/file.md',
+        root: '/home/user',
+        desc: 'fallback if file is inside global gemini dir, even if root overlaps',
+        setup: () => {
+          mockFallback.readTextFile.mockResolvedValue('content');
+        },
+        verify: () => {
+          expect(mockFallback.readTextFile).toHaveBeenCalledWith(
+            '/home/user/.gemini/tmp/file.md',
+          );
+          expect(mockConnection.readTextFile).not.toHaveBeenCalled();
+        },
+      },
+    ])(
+      'should use $desc',
+      async ({ capability, path, root, setup, verify }) => {
+        service = new AcpFileSystemService(
+          mockConnection,
+          'session-1',
+          { readTextFile: capability, writeTextFile: true },
+          mockFallback,
+          root || '/path/to',
+        );
+        setup();
+
+        const result = await service.readTextFile(path);
+
+        expect(result).toBe('content');
+        verify();
+      },
+    );
+
+    it('should throw normalized ENOENT error when readTextFile encounters "Resource not found"', async () => {
+      service = new AcpFileSystemService(
+        mockConnection,
+        'session-1',
+        { readTextFile: true, writeTextFile: true },
+        mockFallback,
+        '/path/to',
+      );
+      mockConnection.readTextFile.mockRejectedValue(
+        new Error('Resource not found for document'),
+      );
+
+      await expect(
+        service.readTextFile('/path/to/missing'),
+      ).rejects.toMatchObject({
+        code: 'ENOENT',
+        message: 'Resource not found for document',
+      });
+    });
+  });
+
+  describe('writeTextFile', () => {
+    it.each([
+      {
+        capability: true,
+        path: '/path/to/file',
+        desc: 'connection if capability exists and file is inside root',
+        verify: () => {
+          expect(mockConnection.writeTextFile).toHaveBeenCalledWith({
+            path: '/path/to/file',
+            content: 'content',
+            sessionId: 'session-1',
+          });
+          expect(mockFallback.writeTextFile).not.toHaveBeenCalled();
+        },
+      },
+      {
+        capability: false,
+        path: '/path/to/file',
+        desc: 'fallback if capability missing',
+        verify: () => {
+          expect(mockFallback.writeTextFile).toHaveBeenCalledWith(
+            '/path/to/file',
+            'content',
+          );
+          expect(mockConnection.writeTextFile).not.toHaveBeenCalled();
+        },
+      },
+      {
+        capability: true,
+        path: '/outside/file',
+        desc: 'fallback if capability exists but file is outside root',
+        verify: () => {
+          expect(mockFallback.writeTextFile).toHaveBeenCalledWith(
+            '/outside/file',
+            'content',
+          );
+          expect(mockConnection.writeTextFile).not.toHaveBeenCalled();
+        },
+      },
+      {
+        capability: true,
+        path: '/home/user/.gemini/tmp/file.md',
+        root: '/home/user',
+        desc: 'fallback if file is inside global gemini dir, even if root overlaps',
+        verify: () => {
+          expect(mockFallback.writeTextFile).toHaveBeenCalledWith(
+            '/home/user/.gemini/tmp/file.md',
+            'content',
+          );
+          expect(mockConnection.writeTextFile).not.toHaveBeenCalled();
+        },
+      },
+    ])('should use $desc', async ({ capability, path, root, verify }) => {
+      service = new AcpFileSystemService(
+        mockConnection,
+        'session-1',
+        { writeTextFile: capability, readTextFile: true },
+        mockFallback,
+        root || '/path/to',
+      );
+
+      await service.writeTextFile(path, 'content');
+
+      verify();
+    });
+
+    it('should throw normalized ENOENT error when writeTextFile encounters "Resource not found"', async () => {
+      service = new AcpFileSystemService(
+        mockConnection,
+        'session-1',
+        { readTextFile: true, writeTextFile: true },
+        mockFallback,
+        '/path/to',
+      );
+      mockConnection.writeTextFile.mockRejectedValue(
+        new Error('Resource not found for directory'),
+      );
+
+      await expect(
+        service.writeTextFile('/path/to/missing', 'content'),
+      ).rejects.toMatchObject({
+        code: 'ENOENT',
+        message: 'Resource not found for directory',
+      });
+    });
+  });
+});

packages/cli/src/acp/acpFileSystemService.ts

@@ -0,0 +1,88 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { isWithinRoot, type FileSystemService } from '@google/gemini-cli-core';
+import type * as acp from '@agentclientprotocol/sdk';
+import os from 'node:os';
+import path from 'node:path';
+
+/**
+ * ACP client-based implementation of FileSystemService
+ */
+export class AcpFileSystemService implements FileSystemService {
+  private readonly geminiDir = path.join(os.homedir(), '.gemini');
+
+  constructor(
+    private readonly connection: acp.AgentSideConnection,
+    private readonly sessionId: string,
+    private readonly capabilities: acp.FileSystemCapabilities,
+    private readonly fallback: FileSystemService,
+    private readonly root: string,
+  ) {}
+
+  private shouldUseFallback(filePath: string): boolean {
+    // Files inside the global CLI directory must always use the native file system,
+    // even if the user runs the CLI directly from their home directory (which
+    // would make the IDE's project root overlap with the global directory).
+    return (
+      !isWithinRoot(filePath, this.root) ||
+      isWithinRoot(filePath, this.geminiDir)
+    );
+  }
+
+  private normalizeFileSystemError(err: unknown): never {
+    const errorMessage = err instanceof Error ? err.message : String(err);
+    if (
+      errorMessage.includes('Resource not found') ||
+      errorMessage.includes('ENOENT') ||
+      errorMessage.includes('does not exist') ||
+      errorMessage.includes('No such file')
+    ) {
+      const newErr = new Error(errorMessage) as NodeJS.ErrnoException;
+      newErr.code = 'ENOENT';
+      throw newErr;
+    }
+    throw err;
+  }
+
+  async readTextFile(filePath: string): Promise<string> {
+    if (!this.capabilities.readTextFile || this.shouldUseFallback(filePath)) {
+      return this.fallback.readTextFile(filePath);
+    }
+
+    try {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const response = await this.connection.readTextFile({
+        path: filePath,
+        sessionId: this.sessionId,
+      });
+
+      const content: unknown = response.content;
+      if (typeof content !== 'string') {
+        throw new Error('content must be a string'); // replace with other response type formats when modified in the future
+      }
+      return content;
+    } catch (err: unknown) {
+      this.normalizeFileSystemError(err);
+    }
+  }
+
+  async writeTextFile(filePath: string, content: string): Promise<void> {
+    if (!this.capabilities.writeTextFile || this.shouldUseFallback(filePath)) {
+      return this.fallback.writeTextFile(filePath, content);
+    }
+
+    try {
+      await this.connection.writeTextFile({
+        path: filePath,
+        content,
+        sessionId: this.sessionId,
+      });
+    } catch (err: unknown) {
+      this.normalizeFileSystemError(err);
+    }
+  }
+}

packages/cli/src/acp/acpResume.test.ts

@@ -0,0 +1,313 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  type Mocked,
+  type Mock,
+} from 'vitest';
+import { GeminiAgent } from './acpRpcDispatcher.js';
+import * as acp from '@agentclientprotocol/sdk';
+import {
+  ApprovalMode,
+  AuthType,
+  type Config,
+  CoreToolCallStatus,
+} from '@google/gemini-cli-core';
+import { loadCliConfig, type CliArgs } from '../config/config.js';
+import {
+  SessionSelector,
+  convertSessionToHistoryFormats,
+} from '../utils/sessionUtils.js';
+import { convertSessionToClientHistory } from '@google/gemini-cli-core';
+import type { LoadedSettings } from '../config/settings.js';
+import { waitFor } from '../test-utils/async.js';
+
+vi.mock('../config/config.js', () => ({
+  loadCliConfig: vi.fn(),
+}));
+
+vi.mock('../utils/sessionUtils.js', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('../utils/sessionUtils.js')>();
+  return {
+    ...actual,
+    SessionSelector: vi.fn(),
+    convertSessionToHistoryFormats: vi.fn(),
+  };
+});
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    CoreToolCallStatus: {
+      Validating: 'validating',
+      Scheduled: 'scheduled',
+      Error: 'error',
+      Success: 'success',
+      Executing: 'executing',
+      Cancelled: 'cancelled',
+      AwaitingApproval: 'awaiting_approval',
+    },
+    LlmRole: {
+      MAIN: 'main',
+      SUBAGENT: 'subagent',
+      UTILITY_TOOL: 'utility_tool',
+      USER: 'user',
+      MODEL: 'model',
+      SYSTEM: 'system',
+      TOOL: 'tool',
+    },
+    convertSessionToClientHistory: vi.fn(),
+  };
+});
+
+describe('GeminiAgent Session Resume', () => {
+  let mockConfig: Mocked<Config>;
+  let mockSettings: Mocked<LoadedSettings>;
+  let mockArgv: CliArgs;
+  let mockConnection: Mocked<acp.AgentSideConnection>;
+  let agent: GeminiAgent;
+
+  beforeEach(() => {
+    mockConfig = {
+      refreshAuth: vi.fn().mockResolvedValue(undefined),
+      initialize: vi.fn().mockResolvedValue(undefined),
+      getFileSystemService: vi.fn(),
+      setFileSystemService: vi.fn(),
+      getGeminiClient: vi.fn().mockReturnValue({
+        initialize: vi.fn().mockResolvedValue(undefined),
+        resumeChat: vi.fn().mockResolvedValue(undefined),
+        getChat: vi.fn().mockReturnValue({}),
+      }),
+      storage: {
+        getProjectTempDir: vi.fn().mockReturnValue('/tmp/project'),
+      },
+      getPolicyEngine: vi.fn().mockReturnValue({
+        addRule: vi.fn(),
+      }),
+      messageBus: {
+        publish: vi.fn(),
+        subscribe: vi.fn(),
+        unsubscribe: vi.fn(),
+      },
+      getMessageBus: vi.fn().mockReturnValue({
+        publish: vi.fn(),
+        subscribe: vi.fn(),
+        unsubscribe: vi.fn(),
+      }),
+      getApprovalMode: vi.fn().mockReturnValue('default'),
+      isAutoMemoryEnabled: vi.fn().mockReturnValue(false),
+      isPlanEnabled: vi.fn().mockReturnValue(true),
+      getModel: vi.fn().mockReturnValue('gemini-pro'),
+      getHasAccessToPreviewModel: vi.fn().mockReturnValue(false),
+      getGemini31LaunchedSync: vi.fn().mockReturnValue(false),
+      getCheckpointingEnabled: vi.fn().mockReturnValue(false),
+      toolRegistry: {
+        getTool: vi.fn().mockReturnValue({ kind: 'read' }),
+      },
+      get config() {
+        return this;
+      },
+    } as unknown as Mocked<Config>;
+    mockSettings = {
+      merged: {
+        security: { auth: { selectedType: AuthType.LOGIN_WITH_GOOGLE } },
+        mcpServers: {},
+      },
+      setValue: vi.fn(),
+    } as unknown as Mocked<LoadedSettings>;
+    mockArgv = {} as unknown as CliArgs;
+    mockConnection = {
+      sessionUpdate: vi.fn().mockResolvedValue(undefined),
+    } as unknown as Mocked<acp.AgentSideConnection>;
+
+    (loadCliConfig as Mock).mockResolvedValue(mockConfig);
+
+    agent = new GeminiAgent(mockConfig, mockSettings, mockArgv, mockConnection);
+  });
+
+  it('should advertise loadSession capability', async () => {
+    const response = await agent.initialize({
+      protocolVersion: acp.PROTOCOL_VERSION,
+    });
+    expect(response.agentCapabilities?.loadSession).toBe(true);
+  });
+
+  it('should load a session, resume chat, and stream all message types', async () => {
+    const sessionId = 'existing-session-id';
+    const sessionData = {
+      sessionId,
+      messages: [
+        { type: 'user', content: [{ text: 'Hello' }] },
+        {
+          type: 'gemini',
+          content: [{ text: 'Hi there' }],
+          thoughts: [{ subject: 'Thinking', description: 'about greeting' }],
+          toolCalls: [
+            {
+              id: 'call-1',
+              name: 'test_tool',
+              displayName: 'Test Tool',
+              status: CoreToolCallStatus.Success,
+              resultDisplay: 'Tool output',
+            },
+          ],
+        },
+        {
+          type: 'gemini',
+          content: [{ text: 'Trying a write' }],
+          toolCalls: [
+            {
+              id: 'call-2',
+              name: 'write_file',
+              displayName: 'Write File',
+              status: CoreToolCallStatus.Error,
+              resultDisplay: 'Permission denied',
+            },
+          ],
+        },
+      ],
+    };
+
+    (SessionSelector as unknown as Mock).mockImplementation(() => ({
+      resolveSession: vi.fn().mockResolvedValue({
+        sessionData,
+        sessionPath: '/path/to/session.json',
+      }),
+    }));
+
+    const mockClientHistory = [
+      { role: 'user', parts: [{ text: 'Hello' }] },
+      { role: 'model', parts: [{ text: 'Hi there' }] },
+    ];
+    (convertSessionToHistoryFormats as unknown as Mock).mockReturnValue({
+      uiHistory: [],
+    });
+    (convertSessionToClientHistory as unknown as Mock).mockReturnValue(
+      mockClientHistory,
+    );
+
+    const response = await agent.loadSession({
+      sessionId,
+      cwd: '/tmp',
+      mcpServers: [],
+    });
+
+    expect(response).toEqual({
+      modes: {
+        availableModes: [
+          {
+            id: ApprovalMode.DEFAULT,
+            name: 'Default',
+            description: 'Prompts for approval',
+          },
+          {
+            id: ApprovalMode.AUTO_EDIT,
+            name: 'Auto Edit',
+            description: 'Auto-approves edit tools',
+          },
+          {
+            id: ApprovalMode.YOLO,
+            name: 'YOLO',
+            description: 'Auto-approves all tools',
+          },
+          {
+            id: ApprovalMode.PLAN,
+            name: 'Plan',
+            description: 'Read-only mode',
+          },
+        ],
+        currentModeId: ApprovalMode.DEFAULT,
+      },
+      models: {
+        availableModels: expect.any(Array) as unknown,
+        currentModelId: 'gemini-pro',
+      },
+    });
+
+    // Verify resumeChat received the correct arguments
+    expect(mockConfig.getGeminiClient().resumeChat).toHaveBeenCalledWith(
+      mockClientHistory,
+      expect.objectContaining({
+        conversation: sessionData,
+        filePath: '/path/to/session.json',
+      }),
+    );
+
+    await waitFor(() => {
+      // User message
+      expect(mockConnection.sessionUpdate).toHaveBeenCalledWith(
+        expect.objectContaining({
+          update: expect.objectContaining({
+            sessionUpdate: 'user_message_chunk',
+            content: expect.objectContaining({ text: 'Hello' }),
+          }),
+        }),
+      );
+
+      // Agent thought
+      expect(mockConnection.sessionUpdate).toHaveBeenCalledWith(
+        expect.objectContaining({
+          update: expect.objectContaining({
+            sessionUpdate: 'agent_thought_chunk',
+            content: expect.objectContaining({
+              text: '**Thinking**\nabout greeting',
+            }),
+          }),
+        }),
+      );
+
+      // Agent message
+      expect(mockConnection.sessionUpdate).toHaveBeenCalledWith(
+        expect.objectContaining({
+          update: expect.objectContaining({
+            sessionUpdate: 'agent_message_chunk',
+            content: expect.objectContaining({ text: 'Hi there' }),
+          }),
+        }),
+      );
+
+      // Successful tool call → 'completed'
+      expect(mockConnection.sessionUpdate).toHaveBeenCalledWith(
+        expect.objectContaining({
+          update: expect.objectContaining({
+            sessionUpdate: 'tool_call',
+            toolCallId: 'call-1',
+            status: 'completed',
+            title: 'Test Tool',
+            kind: 'read',
+            content: [
+              {
+                type: 'content',
+                content: { type: 'text', text: 'Tool output' },
+              },
+            ],
+          }),
+        }),
+      );
+
+      // Failed tool call → 'failed'
+      expect(mockConnection.sessionUpdate).toHaveBeenCalledWith(
+        expect.objectContaining({
+          update: expect.objectContaining({
+            sessionUpdate: 'tool_call',
+            toolCallId: 'call-2',
+            status: 'failed',
+            title: 'Write File',
+            kind: 'read',
+          }),
+        }),
+      );
+    });
+  });
+});

packages/cli/src/acp/acpRpcDispatcher.test.ts

@@ -0,0 +1,339 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  type Mock,
+  type Mocked,
+} from 'vitest';
+import { GeminiAgent } from './acpRpcDispatcher.js';
+import * as acp from '@agentclientprotocol/sdk';
+import {
+  AuthType,
+  type Config,
+  type MessageBus,
+  type Storage,
+} from '@google/gemini-cli-core';
+import type { LoadedSettings } from '../config/settings.js';
+import { loadCliConfig, type CliArgs } from '../config/config.js';
+import { loadSettings, SettingScope } from '../config/settings.js';
+
+vi.mock('../config/config.js', () => ({
+  loadCliConfig: vi.fn(),
+}));
+
+vi.mock('../config/settings.js', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('../config/settings.js')>();
+  return {
+    ...actual,
+    loadSettings: vi.fn(),
+  };
+});
+
+describe('GeminiAgent - RPC Dispatcher', () => {
+  let mockConfig: Mocked<Config>;
+  let mockSettings: Mocked<LoadedSettings>;
+  let mockArgv: CliArgs;
+  let mockConnection: Mocked<acp.AgentSideConnection>;
+  let agent: GeminiAgent;
+
+  beforeEach(() => {
+    mockConfig = {
+      refreshAuth: vi.fn(),
+      initialize: vi.fn(),
+      waitForMcpInit: vi.fn(),
+      getFileSystemService: vi.fn(),
+      setFileSystemService: vi.fn(),
+      getContentGeneratorConfig: vi.fn(),
+      getActiveModel: vi.fn().mockReturnValue('gemini-pro'),
+      getModel: vi.fn().mockReturnValue('gemini-pro'),
+      getGeminiClient: vi.fn().mockReturnValue({
+        startChat: vi.fn().mockResolvedValue({}),
+      }),
+      getMessageBus: vi.fn().mockReturnValue({
+        publish: vi.fn(),
+        subscribe: vi.fn(),
+        unsubscribe: vi.fn(),
+      }),
+      getApprovalMode: vi.fn().mockReturnValue('default'),
+      isPlanEnabled: vi.fn().mockReturnValue(true),
+      getGemini31LaunchedSync: vi.fn().mockReturnValue(false),
+      getHasAccessToPreviewModel: vi.fn().mockReturnValue(false),
+      getCheckpointingEnabled: vi.fn().mockReturnValue(false),
+      getDisableAlwaysAllow: vi.fn().mockReturnValue(false),
+      validatePathAccess: vi.fn().mockReturnValue(null),
+      getWorkspaceContext: vi.fn().mockReturnValue({
+        addReadOnlyPath: vi.fn(),
+        getDirectories: vi.fn().mockReturnValue(['/tmp']),
+      }),
+      getPolicyEngine: vi.fn().mockReturnValue({
+        addRule: vi.fn(),
+      }),
+      messageBus: {
+        publish: vi.fn(),
+        subscribe: vi.fn(),
+        unsubscribe: vi.fn(),
+      } as unknown as MessageBus,
+      storage: {
+        getWorkspaceAutoSavedPolicyPath: vi.fn(),
+        getAutoSavedPolicyPath: vi.fn(),
+      } as unknown as Storage,
+
+      get config() {
+        return this;
+      },
+    } as unknown as Mocked<Config>;
+    mockSettings = {
+      merged: {
+        security: { auth: { selectedType: 'login_with_google' } },
+        mcpServers: {},
+      },
+      setValue: vi.fn(),
+    } as unknown as Mocked<LoadedSettings>;
+    mockArgv = {} as unknown as CliArgs;
+    mockConnection = {
+      sessionUpdate: vi.fn(),
+      requestPermission: vi.fn(),
+    } as unknown as Mocked<acp.AgentSideConnection>;
+
+    (loadCliConfig as unknown as Mock).mockResolvedValue(mockConfig);
+    (loadSettings as unknown as Mock).mockImplementation(() => ({
+      merged: {
+        security: {
+          auth: { selectedType: AuthType.LOGIN_WITH_GOOGLE },
+          enablePermanentToolApproval: true,
+        },
+        mcpServers: {},
+      },
+      setValue: vi.fn(),
+    }));
+
+    agent = new GeminiAgent(mockConfig, mockSettings, mockArgv, mockConnection);
+  });
+
+  it('should initialize correctly', async () => {
+    const response = await agent.initialize({
+      clientCapabilities: { fs: { readTextFile: true, writeTextFile: true } },
+      protocolVersion: 1,
+    });
+
+    expect(response.protocolVersion).toBe(acp.PROTOCOL_VERSION);
+    expect(response.authMethods).toHaveLength(4);
+    const gatewayAuth = response.authMethods?.find(
+      (m) => m.id === AuthType.GATEWAY,
+    );
+    expect(gatewayAuth?._meta).toEqual({
+      gateway: {
+        protocol: 'google',
+        restartRequired: 'false',
+      },
+    });
+    const geminiAuth = response.authMethods?.find(
+      (m) => m.id === AuthType.USE_GEMINI,
+    );
+    expect(geminiAuth?._meta).toEqual({
+      'api-key': {
+        provider: 'google',
+      },
+    });
+    expect(response.agentCapabilities?.loadSession).toBe(true);
+  });
+
+  it('should authenticate correctly', async () => {
+    await agent.authenticate({
+      methodId: AuthType.LOGIN_WITH_GOOGLE,
+    });
+
+    expect(mockConfig.refreshAuth).toHaveBeenCalledWith(
+      AuthType.LOGIN_WITH_GOOGLE,
+      undefined,
+      undefined,
+      undefined,
+    );
+    expect(mockSettings.setValue).toHaveBeenCalledWith(
+      SettingScope.User,
+      'security.auth.selectedType',
+      AuthType.LOGIN_WITH_GOOGLE,
+    );
+  });
+
+  it('should authenticate correctly with api-key in _meta', async () => {
+    await agent.authenticate({
+      methodId: AuthType.USE_GEMINI,
+      _meta: {
+        'api-key': 'test-api-key',
+      },
+    } as unknown as acp.AuthenticateRequest);
+
+    expect(mockConfig.refreshAuth).toHaveBeenCalledWith(
+      AuthType.USE_GEMINI,
+      'test-api-key',
+      undefined,
+      undefined,
+    );
+    expect(mockSettings.setValue).toHaveBeenCalledWith(
+      SettingScope.User,
+      'security.auth.selectedType',
+      AuthType.USE_GEMINI,
+    );
+  });
+
+  it('should authenticate correctly with gateway method', async () => {
+    await agent.authenticate({
+      methodId: AuthType.GATEWAY,
+      _meta: {
+        gateway: {
+          baseUrl: 'https://example.com',
+          headers: { Authorization: 'Bearer token' },
+        },
+      },
+    } as unknown as acp.AuthenticateRequest);
+
+    expect(mockConfig.refreshAuth).toHaveBeenCalledWith(
+      AuthType.GATEWAY,
+      undefined,
+      'https://example.com',
+      { Authorization: 'Bearer token' },
+    );
+    expect(mockSettings.setValue).toHaveBeenCalledWith(
+      SettingScope.User,
+      'security.auth.selectedType',
+      AuthType.GATEWAY,
+    );
+  });
+
+  it('should throw acp.RequestError when gateway payload is malformed', async () => {
+    await expect(
+      agent.authenticate({
+        methodId: AuthType.GATEWAY,
+        _meta: {
+          gateway: {
+            baseUrl: 123,
+            headers: { Authorization: 'Bearer token' },
+          },
+        },
+      } as unknown as acp.AuthenticateRequest),
+    ).rejects.toThrow(/Malformed gateway payload/);
+  });
+
+  it('should cancel a session', async () => {
+    const mockSession = {
+      cancelPendingPrompt: vi.fn(),
+    };
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(mockSession),
+    };
+
+    await agent.cancel({ sessionId: 'test-session-id' });
+
+    expect(mockSession.cancelPendingPrompt).toHaveBeenCalled();
+  });
+
+  it('should throw error when cancelling non-existent session', async () => {
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(undefined),
+    };
+
+    await expect(agent.cancel({ sessionId: 'unknown' })).rejects.toThrow(
+      'Session not found',
+    );
+  });
+
+  it('should delegate prompt to session', async () => {
+    const mockSession = {
+      prompt: vi.fn().mockResolvedValue({ stopReason: 'end_turn' }),
+    };
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(mockSession),
+    };
+
+    const result = await agent.prompt({
+      sessionId: 'test-session-id',
+      prompt: [],
+    });
+
+    expect(mockSession.prompt).toHaveBeenCalled();
+    expect(result).toMatchObject({ stopReason: 'end_turn' });
+  });
+
+  it('should delegate setMode to session', async () => {
+    const mockSession = {
+      setMode: vi.fn().mockReturnValue({}),
+    };
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(mockSession),
+    };
+
+    const result = await agent.setSessionMode({
+      sessionId: 'test-session-id',
+      modeId: 'plan',
+    });
+
+    expect(mockSession.setMode).toHaveBeenCalledWith('plan');
+    expect(result).toEqual({});
+  });
+
+  it('should throw error when setting mode on non-existent session', async () => {
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(undefined),
+    };
+
+    await expect(
+      agent.setSessionMode({
+        sessionId: 'unknown',
+        modeId: 'plan',
+      }),
+    ).rejects.toThrow('Session not found: unknown');
+  });
+
+  it('should delegate setModel to session (unstable)', async () => {
+    const mockSession = {
+      setModel: vi.fn().mockReturnValue({}),
+    };
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(mockSession),
+    };
+
+    const result = await agent.unstable_setSessionModel({
+      sessionId: 'test-session-id',
+      modelId: 'gemini-2.0-pro-exp',
+    });
+
+    expect(mockSession.setModel).toHaveBeenCalledWith('gemini-2.0-pro-exp');
+    expect(result).toEqual({});
+  });
+
+  it('should throw error when setting model on non-existent session (unstable)', async () => {
+    (
+      agent as unknown as { sessionManager: { getSession: Mock } }
+    ).sessionManager = {
+      getSession: vi.fn().mockReturnValue(undefined),
+    };
+
+    await expect(
+      agent.unstable_setSessionModel({
+        sessionId: 'unknown',
+        modelId: 'gemini-2.0-pro-exp',
+      }),
+    ).rejects.toThrow('Session not found: unknown');
+  });
+});

packages/cli/src/acp/acpRpcDispatcher.ts

@@ -0,0 +1,236 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  type AgentLoopContext,
+  AuthType,
+  clearCachedCredentialFile,
+  getVersion,
+} from '@google/gemini-cli-core';
+import * as acp from '@agentclientprotocol/sdk';
+import { z } from 'zod';
+import { SettingScope, type LoadedSettings } from '../config/settings.js';
+import type { CliArgs } from '../config/config.js';
+import { getAcpErrorMessage } from './acpErrors.js';
+import { AcpSessionManager, type AuthDetails } from './acpSessionManager.js';
+import { hasMeta } from './acpUtils.js';
+
+export class GeminiAgent {
+  private apiKey: string | undefined;
+  private baseUrl: string | undefined;
+  private customHeaders: Record<string, string> | undefined;
+  private sessionManager: AcpSessionManager;
+
+  constructor(
+    private context: AgentLoopContext,
+    private settings: LoadedSettings,
+    argv: CliArgs,
+    connection: acp.AgentSideConnection,
+  ) {
+    this.sessionManager = new AcpSessionManager(settings, argv, connection);
+  }
+
+  dispose(): void {
+    this.sessionManager.dispose();
+  }
+
+  async initialize(
+    args: acp.InitializeRequest,
+  ): Promise<acp.InitializeResponse> {
+    if (args.clientCapabilities) {
+      this.sessionManager.setClientCapabilities(args.clientCapabilities);
+    }
+
+    const authMethods = [
+      {
+        id: AuthType.LOGIN_WITH_GOOGLE,
+        name: 'Log in with Google',
+        description: 'Log in with your Google account',
+      },
+      {
+        id: AuthType.USE_GEMINI,
+        name: 'Gemini API key',
+        description: 'Use an API key with Gemini Developer API',
+        _meta: {
+          'api-key': {
+            provider: 'google',
+          },
+        },
+      },
+      {
+        id: AuthType.USE_VERTEX_AI,
+        name: 'Vertex AI',
+        description: 'Use an API key with Vertex AI GenAI API',
+      },
+      {
+        id: AuthType.GATEWAY,
+        name: 'AI API Gateway',
+        description: 'Use a custom AI API Gateway',
+        _meta: {
+          gateway: {
+            protocol: 'google',
+            restartRequired: 'false',
+          },
+        },
+      },
+    ];
+
+    await this.context.config.initialize();
+    const version = await getVersion();
+    return {
+      protocolVersion: acp.PROTOCOL_VERSION,
+      authMethods,
+      agentInfo: {
+        name: 'gemini-cli',
+        title: 'Gemini CLI',
+        version,
+      },
+      agentCapabilities: {
+        loadSession: true,
+        promptCapabilities: {
+          image: true,
+          audio: true,
+          embeddedContext: true,
+        },
+        mcpCapabilities: {
+          http: true,
+          sse: true,
+        },
+      },
+    };
+  }
+
+  async authenticate(req: acp.AuthenticateRequest): Promise<void> {
+    const { methodId } = req;
+    const method = z.nativeEnum(AuthType).parse(methodId);
+    const selectedAuthType = this.settings.merged.security.auth.selectedType;
+
+    // Only clear credentials when switching to a different auth method
+    if (selectedAuthType && selectedAuthType !== method) {
+      await clearCachedCredentialFile();
+    }
+    // Check for api-key in _meta
+    const meta = hasMeta(req) ? req._meta : undefined;
+    const apiKey =
+      typeof meta?.['api-key'] === 'string' ? meta['api-key'] : undefined;
+
+    // Refresh auth with the requested method
+    // This will reuse existing credentials if they're valid,
+    // or perform new authentication if needed
+    try {
+      if (apiKey) {
+        this.apiKey = apiKey;
+      }
+
+      // Extract gateway details if present
+      const gatewaySchema = z.object({
+        baseUrl: z.string().optional(),
+        headers: z.record(z.string()).optional(),
+      });
+
+      let baseUrl: string | undefined;
+      let headers: Record<string, string> | undefined;
+
+      if (meta?.['gateway']) {
+        const result = gatewaySchema.safeParse(meta['gateway']);
+        if (result.success) {
+          baseUrl = result.data.baseUrl;
+          headers = result.data.headers;
+        } else {
+          throw new acp.RequestError(
+            -32602,
+            `Malformed gateway payload: ${result.error.message}`,
+          );
+        }
+      }
+
+      this.baseUrl = baseUrl;
+      this.customHeaders = headers;
+
+      await this.context.config.refreshAuth(
+        method,
+        apiKey ?? this.apiKey,
+        baseUrl,
+        headers,
+      );
+    } catch (e) {
+      throw new acp.RequestError(-32000, getAcpErrorMessage(e));
+    }
+    this.settings.setValue(
+      SettingScope.User,
+      'security.auth.selectedType',
+      method,
+    );
+  }
+
+  private getAuthDetails(): AuthDetails {
+    return {
+      apiKey: this.apiKey,
+      baseUrl: this.baseUrl,
+      customHeaders: this.customHeaders,
+    };
+  }
+
+  async newSession(
+    params: acp.NewSessionRequest,
+  ): Promise<acp.NewSessionResponse> {
+    return this.sessionManager.newSession(params, this.getAuthDetails());
+  }
+
+  async loadSession(
+    params: acp.LoadSessionRequest,
+  ): Promise<acp.LoadSessionResponse> {
+    return this.sessionManager.loadSession(params, this.getAuthDetails());
+  }
+
+  async cancel(params: acp.CancelNotification): Promise<void> {
+    const session = this.sessionManager.getSession(params.sessionId);
+    if (!session) {
+      throw new acp.RequestError(
+        -32602,
+        `Session not found: ${params.sessionId}`,
+      );
+    }
+    await session.cancelPendingPrompt();
+  }
+
+  async prompt(params: acp.PromptRequest): Promise<acp.PromptResponse> {
+    const session = this.sessionManager.getSession(params.sessionId);
+    if (!session) {
+      throw new acp.RequestError(
+        -32602,
+        `Session not found: ${params.sessionId}`,
+      );
+    }
+    return session.prompt(params);
+  }
+
+  async setSessionMode(
+    params: acp.SetSessionModeRequest,
+  ): Promise<acp.SetSessionModeResponse> {
+    const session = this.sessionManager.getSession(params.sessionId);
+    if (!session) {
+      throw new acp.RequestError(
+        -32602,
+        `Session not found: ${params.sessionId}`,
+      );
+    }
+    return session.setMode(params.modeId);
+  }
+
+  async unstable_setSessionModel(
+    params: acp.SetSessionModelRequest,
+  ): Promise<acp.SetSessionModelResponse> {
+    const session = this.sessionManager.getSession(params.sessionId);
+    if (!session) {
+      throw new acp.RequestError(
+        -32602,
+        `Session not found: ${params.sessionId}`,
+      );
+    }
+    return session.setModel(params.modelId);
+  }
+}

packages/cli/src/acp/acpSessionManager.test.ts

@@ -0,0 +1,382 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  afterEach,
+  type Mock,
+  type Mocked,
+} from 'vitest';
+import { AcpSessionManager } from './acpSessionManager.js';
+import type * as acp from '@agentclientprotocol/sdk';
+import {
+  AuthType,
+  type Config,
+  GEMINI_MODEL_ALIAS_AUTO,
+  type MessageBus,
+  type Storage,
+} from '@google/gemini-cli-core';
+import type { LoadedSettings } from '../config/settings.js';
+import { loadCliConfig, type CliArgs } from '../config/config.js';
+import { loadSettings } from '../config/settings.js';
+
+vi.mock('../config/config.js', () => ({
+  loadCliConfig: vi.fn(),
+}));
+
+vi.mock('../config/settings.js', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('../config/settings.js')>();
+  return {
+    ...actual,
+    loadSettings: vi.fn(),
+  };
+});
+
+const startAutoMemoryIfEnabledMock = vi.fn();
+vi.mock('../utils/autoMemory.js', () => ({
+  startAutoMemoryIfEnabled: (config: Config) =>
+    startAutoMemoryIfEnabledMock(config),
+}));
+
+describe('AcpSessionManager', () => {
+  let mockConfig: Mocked<Config>;
+  let mockSettings: Mocked<LoadedSettings>;
+  let mockArgv: CliArgs;
+  let mockConnection: Mocked<acp.AgentSideConnection>;
+  let manager: AcpSessionManager;
+
+  beforeEach(() => {
+    mockConfig = {
+      refreshAuth: vi.fn(),
+      initialize: vi.fn(),
+      waitForMcpInit: vi.fn(),
+      getFileSystemService: vi.fn(),
+      setFileSystemService: vi.fn(),
+      getContentGeneratorConfig: vi.fn(),
+      getActiveModel: vi.fn().mockReturnValue('gemini-pro'),
+      getModel: vi.fn().mockReturnValue('gemini-pro'),
+      getGeminiClient: vi.fn().mockReturnValue({
+        startChat: vi.fn().mockResolvedValue({}),
+      }),
+      getMessageBus: vi.fn().mockReturnValue({
+        publish: vi.fn(),
+        subscribe: vi.fn(),
+        unsubscribe: vi.fn(),
+      }),
+      getApprovalMode: vi.fn().mockReturnValue('default'),
+      isPlanEnabled: vi.fn().mockReturnValue(true),
+      getGemini31LaunchedSync: vi.fn().mockReturnValue(false),
+      getHasAccessToPreviewModel: vi.fn().mockReturnValue(false),
+      getCheckpointingEnabled: vi.fn().mockReturnValue(false),
+      getDisableAlwaysAllow: vi.fn().mockReturnValue(false),
+      validatePathAccess: vi.fn().mockReturnValue(null),
+      getWorkspaceContext: vi.fn().mockReturnValue({
+        addReadOnlyPath: vi.fn(),
+        getDirectories: vi.fn().mockReturnValue(['/tmp']),
+      }),
+      getPolicyEngine: vi.fn().mockReturnValue({
+        addRule: vi.fn(),
+      }),
+      messageBus: {
+        publish: vi.fn(),
+        subscribe: vi.fn(),
+        unsubscribe: vi.fn(),
+      } as unknown as MessageBus,
+      storage: {
+        getWorkspaceAutoSavedPolicyPath: vi.fn(),
+        getAutoSavedPolicyPath: vi.fn(),
+      } as unknown as Storage,
+
+      get config() {
+        return this;
+      },
+    } as unknown as Mocked<Config>;
+    mockSettings = {
+      merged: {
+        security: { auth: { selectedType: 'login_with_google' } },
+        mcpServers: {},
+      },
+      setValue: vi.fn(),
+    } as unknown as Mocked<LoadedSettings>;
+    mockArgv = {} as unknown as CliArgs;
+    mockConnection = {
+      sessionUpdate: vi.fn(),
+      requestPermission: vi.fn(),
+    } as unknown as Mocked<acp.AgentSideConnection>;
+
+    (loadCliConfig as unknown as Mock).mockResolvedValue(mockConfig);
+    (loadSettings as unknown as Mock).mockImplementation(() => ({
+      merged: {
+        security: {
+          auth: { selectedType: AuthType.LOGIN_WITH_GOOGLE },
+          enablePermanentToolApproval: true,
+        },
+        mcpServers: {},
+      },
+      setValue: vi.fn(),
+    }));
+
+    manager = new AcpSessionManager(mockSettings, mockArgv, mockConnection);
+    vi.mock('node:crypto', () => ({
+      randomUUID: () => 'test-session-id',
+    }));
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('should create a new session', async () => {
+    vi.useFakeTimers();
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    const response = await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    expect(response.sessionId).toBe('test-session-id');
+    expect(loadCliConfig).toHaveBeenCalled();
+    expect(mockConfig.initialize).toHaveBeenCalled();
+    expect(mockConfig.getGeminiClient).toHaveBeenCalled();
+
+    // Verify deferred call (sendAvailableCommands)
+    await vi.runAllTimersAsync();
+    expect(mockConnection.sessionUpdate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        update: expect.objectContaining({
+          sessionUpdate: 'available_commands_update',
+        }),
+      }),
+    );
+    vi.useRealTimers();
+  });
+
+  it('should return modes without plan mode when plan is disabled', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    mockConfig.isPlanEnabled = vi.fn().mockReturnValue(false);
+    mockConfig.getApprovalMode = vi.fn().mockReturnValue('default');
+
+    const response = await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    expect(response.modes).toEqual({
+      availableModes: [
+        { id: 'default', name: 'Default', description: 'Prompts for approval' },
+        {
+          id: 'autoEdit',
+          name: 'Auto Edit',
+          description: 'Auto-approves edit tools',
+        },
+        { id: 'yolo', name: 'YOLO', description: 'Auto-approves all tools' },
+      ],
+      currentModeId: 'default',
+    });
+  });
+
+  it('should include preview models when user has access', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    mockConfig.getHasAccessToPreviewModel = vi.fn().mockReturnValue(true);
+    mockConfig.getGemini31LaunchedSync = vi.fn().mockReturnValue(true);
+
+    const response = await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    expect(response.models?.availableModels).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({
+          modelId: GEMINI_MODEL_ALIAS_AUTO,
+          name: expect.stringContaining('Auto'),
+        }),
+      ]),
+    );
+  });
+
+  it('should NOT include retired preview models (none) in available models', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    mockConfig.getHasAccessToPreviewModel = vi.fn().mockReturnValue(true);
+    mockConfig.getGemini31LaunchedSync = vi.fn().mockReturnValue(true);
+
+    const response = await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    const modelIds =
+      response.models?.availableModels?.map((m) => m.modelId) ?? [];
+    expect(modelIds).not.toContain('none');
+  });
+
+  it('should return modes with plan mode when plan is enabled', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    mockConfig.isPlanEnabled = vi.fn().mockReturnValue(true);
+    mockConfig.getApprovalMode = vi.fn().mockReturnValue('plan');
+
+    const response = await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    expect(response.modes).toEqual({
+      availableModes: [
+        { id: 'default', name: 'Default', description: 'Prompts for approval' },
+        {
+          id: 'autoEdit',
+          name: 'Auto Edit',
+          description: 'Auto-approves edit tools',
+        },
+        { id: 'yolo', name: 'YOLO', description: 'Auto-approves all tools' },
+        { id: 'plan', name: 'Plan', description: 'Read-only mode' },
+      ],
+      currentModeId: 'plan',
+    });
+  });
+
+  it('should fail session creation if Gemini API key is missing', async () => {
+    (loadSettings as unknown as Mock).mockImplementation(() => ({
+      merged: {
+        security: { auth: { selectedType: AuthType.USE_GEMINI } },
+        mcpServers: {},
+      },
+      setValue: vi.fn(),
+    }));
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: undefined,
+    });
+
+    await expect(
+      manager.newSession(
+        {
+          cwd: '/tmp',
+          mcpServers: [],
+        },
+        {},
+      ),
+    ).rejects.toMatchObject({
+      message: 'Gemini API key is missing or not configured.',
+    });
+  });
+
+  it('should create a new session with mcp servers', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    const mcpServers = [
+      {
+        name: 'test-server',
+        command: 'node',
+        args: ['server.js'],
+        env: [{ name: 'KEY', value: 'VALUE' }],
+      },
+    ];
+
+    await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers,
+      },
+      {},
+    );
+
+    expect(loadCliConfig).toHaveBeenCalledWith(
+      expect.objectContaining({
+        mcpServers: expect.objectContaining({
+          'test-server': expect.objectContaining({
+            command: 'node',
+            args: ['server.js'],
+            env: { KEY: 'VALUE' },
+          }),
+        }),
+      }),
+      'test-session-id',
+      mockArgv,
+      { cwd: '/tmp' },
+    );
+  });
+
+  it('should handle authentication failure gracefully', async () => {
+    mockConfig.refreshAuth.mockRejectedValue(new Error('Auth failed'));
+
+    await expect(
+      manager.newSession(
+        {
+          cwd: '/tmp',
+          mcpServers: [],
+        },
+        {},
+      ),
+    ).rejects.toMatchObject({
+      message: 'Auth failed',
+    });
+  });
+
+  it('should initialize file system service if client supports it', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+    manager.setClientCapabilities({
+      fs: { readTextFile: true, writeTextFile: true },
+    });
+
+    await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    expect(mockConfig.setFileSystemService).toHaveBeenCalled();
+  });
+
+  it('should start auto memory for new ACP sessions', async () => {
+    mockConfig.getContentGeneratorConfig = vi.fn().mockReturnValue({
+      apiKey: 'test-key',
+    });
+
+    await manager.newSession(
+      {
+        cwd: '/tmp',
+        mcpServers: [],
+      },
+      {},
+    );
+
+    expect(startAutoMemoryIfEnabledMock).toHaveBeenCalledWith(mockConfig);
+  });
+});

packages/cli/src/acp/acpSessionManager.ts

@@ -0,0 +1,343 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  type Config,
+  AuthType,
+  MCPServerConfig,
+  debugLogger,
+  startupProfiler,
+  convertSessionToClientHistory,
+  createPolicyUpdater,
+} from '@google/gemini-cli-core';
+import * as acp from '@agentclientprotocol/sdk';
+import { randomUUID } from 'node:crypto';
+import { loadSettings, type LoadedSettings } from '../config/settings.js';
+import { SessionSelector } from '../utils/sessionUtils.js';
+import { Session } from './acpSession.js';
+import { AcpFileSystemService } from './acpFileSystemService.js';
+import { getAcpErrorMessage } from './acpErrors.js';
+import { buildAvailableModels, buildAvailableModes } from './acpUtils.js';
+import { loadCliConfig, type CliArgs } from '../config/config.js';
+import { startAutoMemoryIfEnabled } from '../utils/autoMemory.js';
+
+export interface AuthDetails {
+  apiKey?: string;
+  baseUrl?: string;
+  customHeaders?: Record<string, string>;
+}
+
+export class AcpSessionManager {
+  private sessions: Map<string, Session> = new Map();
+  private clientCapabilities: acp.ClientCapabilities | undefined;
+
+  constructor(
+    private settings: LoadedSettings,
+    private argv: CliArgs,
+    private connection: acp.AgentSideConnection,
+  ) {}
+
+  setClientCapabilities(capabilities: acp.ClientCapabilities) {
+    this.clientCapabilities = capabilities;
+  }
+
+  getSession(sessionId: string): Session | undefined {
+    return this.sessions.get(sessionId);
+  }
+
+  dispose(): void {
+    for (const session of this.sessions.values()) {
+      session.dispose();
+    }
+    this.sessions.clear();
+  }
+
+  async newSession(
+    { cwd, mcpServers }: acp.NewSessionRequest,
+    authDetails: AuthDetails,
+  ): Promise<acp.NewSessionResponse> {
+    const sessionId = randomUUID();
+    const loadedSettings = loadSettings(cwd);
+    const config = await this.newSessionConfig(
+      sessionId,
+      cwd,
+      mcpServers,
+      loadedSettings,
+    );
+
+    const authType =
+      loadedSettings.merged.security.auth.selectedType ||
+      (authDetails.baseUrl || process.env['GOOGLE_GEMINI_BASE_URL']
+        ? AuthType.GATEWAY
+        : AuthType.USE_GEMINI);
+
+    let isAuthenticated = false;
+    let authErrorMessage = '';
+    try {
+      await config.refreshAuth(
+        authType,
+        authDetails.apiKey,
+        authDetails.baseUrl,
+        authDetails.customHeaders,
+      );
+      isAuthenticated = true;
+
+      // Extra validation for Gemini API key
+      const contentGeneratorConfig = config.getContentGeneratorConfig();
+      if (
+        authType === AuthType.USE_GEMINI &&
+        (!contentGeneratorConfig || !contentGeneratorConfig.apiKey)
+      ) {
+        isAuthenticated = false;
+        authErrorMessage = 'Gemini API key is missing or not configured.';
+      }
+    } catch (e) {
+      isAuthenticated = false;
+      authErrorMessage = getAcpErrorMessage(e);
+      debugLogger.error(
+        `Authentication failed: ${e instanceof Error ? e.stack : e}`,
+      );
+    }
+
+    if (!isAuthenticated) {
+      throw new acp.RequestError(
+        -32000,
+        authErrorMessage || 'Authentication required.',
+      );
+    }
+
+    if (this.clientCapabilities?.fs) {
+      const acpFileSystemService = new AcpFileSystemService(
+        this.connection,
+        sessionId,
+        this.clientCapabilities.fs,
+        config.getFileSystemService(),
+        cwd,
+      );
+      config.setFileSystemService(acpFileSystemService);
+    }
+
+    await config.initialize();
+    startupProfiler.flush(config);
+    startAutoMemoryIfEnabled(config);
+
+    const geminiClient = config.getGeminiClient();
+
+    const chat = await geminiClient.startChat();
+
+    const session = new Session(
+      sessionId,
+      chat,
+      config,
+      this.connection,
+      this.settings,
+    );
+    this.sessions.set(sessionId, session);
+
+    setTimeout(() => {
+      // eslint-disable-next-line @typescript-eslint/no-floating-promises
+      session.sendAvailableCommands();
+    }, 0);
+
+    const { availableModels, currentModelId } = buildAvailableModels(
+      config,
+      loadedSettings,
+    );
+
+    const response = {
+      sessionId,
+      modes: {
+        availableModes: buildAvailableModes(config.isPlanEnabled()),
+        currentModeId: config.getApprovalMode(),
+      },
+      models: {
+        availableModels,
+        currentModelId,
+      },
+    };
+    return response;
+  }
+
+  async loadSession(
+    { sessionId, cwd, mcpServers }: acp.LoadSessionRequest,
+    authDetails: AuthDetails,
+  ): Promise<acp.LoadSessionResponse> {
+    const config = await this.initializeSessionConfig(
+      sessionId,
+      cwd,
+      mcpServers,
+      authDetails,
+    );
+
+    const sessionSelector = new SessionSelector(config.storage);
+
+    const { sessionData, sessionPath } =
+      await sessionSelector.resolveSession(sessionId);
+
+    const clientHistory = convertSessionToClientHistory(sessionData.messages);
+
+    const geminiClient = config.getGeminiClient();
+    await geminiClient.initialize();
+    await geminiClient.resumeChat(clientHistory, {
+      conversation: sessionData,
+      filePath: sessionPath,
+    });
+
+    const session = new Session(
+      sessionId,
+      geminiClient.getChat(),
+      config,
+      this.connection,
+      this.settings,
+    );
+
+    const existingSession = this.sessions.get(sessionId);
+    if (existingSession) {
+      existingSession.dispose();
+    }
+
+    this.sessions.set(sessionId, session);
+
+    // Stream history back to client
+    // eslint-disable-next-line @typescript-eslint/no-floating-promises
+    session.streamHistory(sessionData.messages);
+
+    setTimeout(() => {
+      // eslint-disable-next-line @typescript-eslint/no-floating-promises
+      session.sendAvailableCommands();
+    }, 0);
+
+    const { availableModels, currentModelId } = buildAvailableModels(
+      config,
+      this.settings,
+    );
+
+    const response = {
+      modes: {
+        availableModes: buildAvailableModes(config.isPlanEnabled()),
+        currentModeId: config.getApprovalMode(),
+      },
+      models: {
+        availableModels,
+        currentModelId,
+      },
+    };
+    return response;
+  }
+
+  private async initializeSessionConfig(
+    sessionId: string,
+    cwd: string,
+    mcpServers: acp.McpServer[],
+    authDetails: AuthDetails,
+  ): Promise<Config> {
+    const selectedAuthType =
+      this.settings.merged.security.auth.selectedType ||
+      (authDetails.baseUrl || process.env['GOOGLE_GEMINI_BASE_URL']
+        ? AuthType.GATEWAY
+        : undefined);
+
+    if (!selectedAuthType) {
+      throw acp.RequestError.authRequired();
+    }
+
+    // 1. Create config WITHOUT initializing it (no MCP servers started yet)
+    const config = await this.newSessionConfig(sessionId, cwd, mcpServers);
+
+    // 2. Authenticate BEFORE initializing configuration or starting MCP servers.
+    // This satisfies the security requirement to verify the user before executing
+    // potentially unsafe server definitions.
+    try {
+      await config.refreshAuth(
+        selectedAuthType,
+        authDetails.apiKey,
+        authDetails.baseUrl,
+        authDetails.customHeaders,
+      );
+    } catch (e) {
+      debugLogger.error(`Authentication failed: ${e}`);
+      throw acp.RequestError.authRequired();
+    }
+
+    // 3. Set the ACP FileSystemService (if supported) before config initialization
+    if (this.clientCapabilities?.fs) {
+      const acpFileSystemService = new AcpFileSystemService(
+        this.connection,
+        sessionId,
+        this.clientCapabilities.fs,
+        config.getFileSystemService(),
+        cwd,
+      );
+      config.setFileSystemService(acpFileSystemService);
+    }
+
+    // 4. Now that we are authenticated, it is safe to initialize the config
+    // which starts the MCP servers and other heavy resources.
+    await config.initialize();
+    startupProfiler.flush(config);
+    startAutoMemoryIfEnabled(config);
+
+    return config;
+  }
+
+  async newSessionConfig(
+    sessionId: string,
+    cwd: string,
+    mcpServers: acp.McpServer[],
+    loadedSettings?: LoadedSettings,
+  ): Promise<Config> {
+    const currentSettings = loadedSettings || this.settings;
+    const mergedMcpServers = { ...currentSettings.merged.mcpServers };
+
+    for (const server of mcpServers) {
+      if (
+        'type' in server &&
+        (server.type === 'sse' || server.type === 'http')
+      ) {
+        // HTTP or SSE MCP server
+        const headers = Object.fromEntries(
+          server.headers.map(({ name, value }) => [name, value]),
+        );
+        mergedMcpServers[server.name] = new MCPServerConfig(
+          undefined, // command
+          undefined, // args
+          undefined, // env
+          undefined, // cwd
+          server.type === 'sse' ? server.url : undefined, // url (sse)
+          server.type === 'http' ? server.url : undefined, // httpUrl
+          headers,
+        );
+      } else if ('command' in server) {
+        // Stdio MCP server
+        const env: Record<string, string> = {};
+        for (const { name: envName, value } of server.env) {
+          env[envName] = value;
+        }
+        mergedMcpServers[server.name] = new MCPServerConfig(
+          server.command,
+          server.args,
+          env,
+          cwd,
+        );
+      }
+    }
+
+    const settings = {
+      ...currentSettings.merged,
+      mcpServers: mergedMcpServers,
+    };
+
+    const config = await loadCliConfig(settings, sessionId, this.argv, { cwd });
+
+    createPolicyUpdater(
+      config.getPolicyEngine(),
+      config.messageBus,
+      config.storage,
+    );
+
+    return config;
+  }
+}

packages/cli/src/acp/acpStdioTransport.ts

@@ -0,0 +1,35 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { type Config, createWorkingStdio } from '@google/gemini-cli-core';
+import { runExitCleanup } from '../utils/cleanup.js';
+import * as acp from '@agentclientprotocol/sdk';
+import { Readable, Writable } from 'node:stream';
+import type { LoadedSettings } from '../config/settings.js';
+import type { CliArgs } from '../config/config.js';
+import { GeminiAgent } from './acpRpcDispatcher.js';
+
+export async function runAcpClient(
+  config: Config,
+  settings: LoadedSettings,
+  argv: CliArgs,
+) {
+  const { stdout: workingStdout } = createWorkingStdio();
+  const stdout = Writable.toWeb(workingStdout) as WritableStream;
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const stdin = Readable.toWeb(process.stdin) as ReadableStream<Uint8Array>;
+
+  const stream = acp.ndJsonStream(stdout, stdin);
+  const connection = new acp.AgentSideConnection(
+    (connection) => new GeminiAgent(config, settings, argv, connection),
+    stream,
+  );
+
+  // SIGTERM/SIGINT handlers (in sdk.ts) don't fire when stdin closes.
+  // We must explicitly await the connection close to flush telemetry.
+  // Use finally() to ensure cleanup runs even on stream errors.
+  await connection.closed.finally(runExitCleanup);
+}

packages/cli/src/acp/acpUtils.ts

@@ -0,0 +1,365 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  type Config,
+  type ToolResult,
+  type ToolCallConfirmationDetails,
+  Kind,
+  ApprovalMode,
+  GEMINI_MODEL_ALIAS_AUTO,
+  DEFAULT_GEMINI_MODEL,
+  DEFAULT_GEMINI_FLASH_MODEL,
+  DEFAULT_GEMINI_FLASH_LITE_MODEL,
+  PREVIEW_GEMINI_3_1_MODEL,
+  PREVIEW_GEMINI_MODEL,
+  PREVIEW_GEMINI_3_1_CUSTOM_TOOLS_MODEL,
+  PREVIEW_GEMINI_FLASH_MODEL,
+  PREVIEW_GEMINI_FLASH_LITE_MODEL,
+  getDisplayString,
+  AuthType,
+  ToolConfirmationOutcome,
+  getAutoModelDescription,
+} from '@google/gemini-cli-core';
+import type * as acp from '@agentclientprotocol/sdk';
+import { z } from 'zod';
+import type { LoadedSettings } from '../config/settings.js';
+
+export function hasMeta(
+  obj: unknown,
+): obj is { _meta?: Record<string, unknown> } {
+  return typeof obj === 'object' && obj !== null && '_meta' in obj;
+}
+
+export const RequestPermissionResponseSchema = z.object({
+  outcome: z.discriminatedUnion('outcome', [
+    z.object({ outcome: z.literal('cancelled') }),
+    z.object({
+      outcome: z.literal('selected'),
+      optionId: z.string(),
+    }),
+  ]),
+});
+
+export function toToolCallContent(
+  toolResult: ToolResult,
+): acp.ToolCallContent | null {
+  if (toolResult.error?.message) {
+    throw new Error(toolResult.error.message);
+  }
+
+  if (toolResult.returnDisplay) {
+    if (typeof toolResult.returnDisplay === 'string') {
+      return {
+        type: 'content',
+        content: { type: 'text', text: toolResult.returnDisplay },
+      };
+    } else {
+      if ('fileName' in toolResult.returnDisplay) {
+        return {
+          type: 'diff',
+          path:
+            toolResult.returnDisplay.filePath ??
+            toolResult.returnDisplay.fileName,
+          oldText: toolResult.returnDisplay.originalContent,
+          newText: toolResult.returnDisplay.newContent,
+          _meta: {
+            kind: !toolResult.returnDisplay.originalContent
+              ? 'add'
+              : toolResult.returnDisplay.newContent === ''
+                ? 'delete'
+                : 'modify',
+          },
+        };
+      }
+      return null;
+    }
+  } else {
+    return null;
+  }
+}
+
+const basicPermissionOptions = [
+  {
+    optionId: ToolConfirmationOutcome.ProceedOnce,
+    name: 'Allow',
+    kind: 'allow_once',
+  },
+  {
+    optionId: ToolConfirmationOutcome.Cancel,
+    name: 'Reject',
+    kind: 'reject_once',
+  },
+] as const;
+
+export function toPermissionOptions(
+  confirmation: ToolCallConfirmationDetails,
+  config: Config,
+  enablePermanentToolApproval: boolean = false,
+): acp.PermissionOption[] {
+  const disableAlwaysAllow = config.getDisableAlwaysAllow();
+  const options: acp.PermissionOption[] = [];
+
+  if (!disableAlwaysAllow) {
+    switch (confirmation.type) {
+      case 'edit':
+        options.push({
+          optionId: ToolConfirmationOutcome.ProceedAlways,
+          name: 'Allow for this session',
+          kind: 'allow_always',
+        });
+        if (enablePermanentToolApproval) {
+          options.push({
+            optionId: ToolConfirmationOutcome.ProceedAlwaysAndSave,
+            name: 'Allow for this file in all future sessions',
+            kind: 'allow_always',
+          });
+        }
+        break;
+      case 'exec':
+        options.push({
+          optionId: ToolConfirmationOutcome.ProceedAlways,
+          name: 'Allow for this session',
+          kind: 'allow_always',
+        });
+        if (enablePermanentToolApproval) {
+          options.push({
+            optionId: ToolConfirmationOutcome.ProceedAlwaysAndSave,
+            name: 'Allow this command for all future sessions',
+            kind: 'allow_always',
+          });
+        }
+        break;
+      case 'mcp':
+        options.push(
+          {
+            optionId: ToolConfirmationOutcome.ProceedAlwaysServer,
+            name: 'Allow all server tools for this session',
+            kind: 'allow_always',
+          },
+          {
+            optionId: ToolConfirmationOutcome.ProceedAlwaysTool,
+            name: 'Allow tool for this session',
+            kind: 'allow_always',
+          },
+        );
+        if (enablePermanentToolApproval) {
+          options.push({
+            optionId: ToolConfirmationOutcome.ProceedAlwaysAndSave,
+            name: 'Allow tool for all future sessions',
+            kind: 'allow_always',
+          });
+        }
+        break;
+      case 'info':
+        options.push({
+          optionId: ToolConfirmationOutcome.ProceedAlways,
+          name: 'Allow for this session',
+          kind: 'allow_always',
+        });
+        if (enablePermanentToolApproval) {
+          options.push({
+            optionId: ToolConfirmationOutcome.ProceedAlwaysAndSave,
+            name: 'Allow for all future sessions',
+            kind: 'allow_always',
+          });
+        }
+        break;
+      case 'ask_user':
+      case 'exit_plan_mode':
+        // askuser and exit_plan_mode don't need "always allow" options
+        break;
+      default:
+        // No "always allow" options for other types
+        break;
+    }
+  }
+
+  options.push(...basicPermissionOptions);
+
+  // Exhaustive check
+  switch (confirmation.type) {
+    case 'edit':
+    case 'exec':
+    case 'mcp':
+    case 'info':
+    case 'ask_user':
+    case 'exit_plan_mode':
+    case 'sandbox_expansion':
+      break;
+    default: {
+      const unreachable: never = confirmation;
+      throw new Error(`Unexpected: ${unreachable}`);
+    }
+  }
+
+  return options;
+}
+
+export function toAcpToolKind(kind: Kind): acp.ToolKind {
+  switch (kind) {
+    case Kind.Read:
+    case Kind.Edit:
+    case Kind.Execute:
+    case Kind.Search:
+    case Kind.Delete:
+    case Kind.Move:
+    case Kind.Think:
+    case Kind.Fetch:
+    case Kind.SwitchMode:
+    case Kind.Other:
+      return kind as acp.ToolKind;
+    case Kind.Agent:
+      return 'think';
+    case Kind.Plan:
+    case Kind.Communicate:
+    default:
+      return 'other';
+  }
+}
+
+export function buildAvailableModes(isPlanEnabled: boolean): acp.SessionMode[] {
+  const modes: acp.SessionMode[] = [
+    {
+      id: ApprovalMode.DEFAULT,
+      name: 'Default',
+      description: 'Prompts for approval',
+    },
+    {
+      id: ApprovalMode.AUTO_EDIT,
+      name: 'Auto Edit',
+      description: 'Auto-approves edit tools',
+    },
+    {
+      id: ApprovalMode.YOLO,
+      name: 'YOLO',
+      description: 'Auto-approves all tools',
+    },
+  ];
+
+  if (isPlanEnabled) {
+    modes.push({
+      id: ApprovalMode.PLAN,
+      name: 'Plan',
+      description: 'Read-only mode',
+    });
+  }
+
+  return modes;
+}
+
+export function buildAvailableModels(
+  config: Config,
+  settings: LoadedSettings,
+): {
+  availableModels: Array<{
+    modelId: string;
+    name: string;
+    description?: string;
+  }>;
+  currentModelId: string;
+} {
+  const preferredModel = config.getModel() || GEMINI_MODEL_ALIAS_AUTO;
+  const shouldShowPreviewModels = config.getHasAccessToPreviewModel();
+  const useGemini31 = config.getGemini31LaunchedSync?.() ?? false;
+  const useGemini3_5Flash = config.hasGemini35FlashGAAccess?.() ?? false;
+  const selectedAuthType = settings.merged.security.auth.selectedType;
+  const useCustomToolModel =
+    useGemini31 && selectedAuthType === AuthType.USE_GEMINI;
+
+  // --- DYNAMIC PATH ---
+  if (
+    config.getExperimentalDynamicModelConfiguration?.() === true &&
+    config.getModelConfigService
+  ) {
+    const options = config.getModelConfigService().getAvailableModelOptions({
+      useGemini3_1: useGemini31,
+      useGemini3_5Flash,
+      useCustomTools: useCustomToolModel,
+      hasAccessToPreview: shouldShowPreviewModels,
+    });
+
+    return {
+      availableModels: options,
+      currentModelId: preferredModel,
+    };
+  }
+
+  // --- LEGACY PATH ---
+  const mainOptions = [
+    {
+      value: GEMINI_MODEL_ALIAS_AUTO,
+      title: getDisplayString(GEMINI_MODEL_ALIAS_AUTO),
+      description: getAutoModelDescription(
+        shouldShowPreviewModels,
+        useGemini31,
+        useGemini3_5Flash,
+      ),
+    },
+  ];
+
+  const manualOptions = [
+    {
+      value: DEFAULT_GEMINI_MODEL,
+      title: getDisplayString(DEFAULT_GEMINI_MODEL),
+    },
+    {
+      value: DEFAULT_GEMINI_FLASH_MODEL,
+      title: getDisplayString(DEFAULT_GEMINI_FLASH_MODEL),
+    },
+    {
+      value: DEFAULT_GEMINI_FLASH_LITE_MODEL,
+      title: getDisplayString(DEFAULT_GEMINI_FLASH_LITE_MODEL),
+    },
+  ];
+
+  if (shouldShowPreviewModels) {
+    const previewProModel = useGemini31
+      ? PREVIEW_GEMINI_3_1_MODEL
+      : PREVIEW_GEMINI_MODEL;
+
+    const previewProValue = useCustomToolModel
+      ? PREVIEW_GEMINI_3_1_CUSTOM_TOOLS_MODEL
+      : previewProModel;
+
+    const previewOptions = [
+      {
+        value: previewProValue,
+        title: getDisplayString(previewProModel),
+      },
+      {
+        value: PREVIEW_GEMINI_FLASH_MODEL,
+        title: getDisplayString(PREVIEW_GEMINI_FLASH_MODEL),
+      },
+    ];
+
+    if (PREVIEW_GEMINI_FLASH_LITE_MODEL !== 'none') {
+      previewOptions.push({
+        value: PREVIEW_GEMINI_FLASH_LITE_MODEL,
+        title: getDisplayString(PREVIEW_GEMINI_FLASH_LITE_MODEL),
+      });
+    }
+
+    manualOptions.unshift(...previewOptions);
+  }
+
+  const scaleOptions = (
+    options: Array<{ value: string; title: string; description?: string }>,
+  ) =>
+    options.map((o) => ({
+      modelId: o.value,
+      name: o.title,
+      description: o.description,
+    }));
+
+  return {
+    availableModels: [
+      ...scaleOptions(mainOptions),
+      ...scaleOptions(manualOptions),
+    ],
+    currentModelId: preferredModel,
+  };
+}

packages/cli/src/acp/commands/about.ts

@@ -0,0 +1,74 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  IdeClient,
+  UserAccountManager,
+  getVersion,
+} from '@google/gemini-cli-core';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+import process from 'node:process';
+
+export class AboutCommand implements Command {
+  readonly name = 'about';
+  readonly description = 'Show version and environment info';
+
+  async execute(
+    context: CommandContext,
+    _args: string[] = [],
+  ): Promise<CommandExecutionResponse> {
+    const osVersion = process.platform;
+    let sandboxEnv = 'no sandbox';
+    if (process.env['SANDBOX'] && process.env['SANDBOX'] !== 'sandbox-exec') {
+      sandboxEnv = process.env['SANDBOX'];
+    } else if (process.env['SANDBOX'] === 'sandbox-exec') {
+      sandboxEnv = `sandbox-exec (${
+        process.env['SEATBELT_PROFILE'] || 'unknown'
+      })`;
+    }
+    const modelVersion = context.agentContext.config.getModel() || 'Unknown';
+    const cliVersion = await getVersion();
+    const selectedAuthType =
+      context.settings.merged?.security?.auth?.selectedType ?? '';
+    const gcpProject = process.env['GOOGLE_CLOUD_PROJECT'] || '';
+    const ideClient = await getIdeClientName(context);
+
+    const userAccountManager = new UserAccountManager();
+    const cachedAccount = userAccountManager.getCachedGoogleAccount();
+    const userEmail = cachedAccount ?? 'Unknown';
+
+    const tier = context.agentContext.config.getUserTierName() || 'Unknown';
+
+    const info = [
+      `- Version: ${cliVersion}`,
+      `- OS: ${osVersion}`,
+      `- Sandbox: ${sandboxEnv}`,
+      `- Model: ${modelVersion}`,
+      `- Auth Type: ${selectedAuthType}`,
+      `- GCP Project: ${gcpProject}`,
+      `- IDE Client: ${ideClient}`,
+      `- User Email: ${userEmail}`,
+      `- Tier: ${tier}`,
+    ].join('\n');
+
+    return {
+      name: this.name,
+      data: `Gemini CLI Info:\n${info}`,
+    };
+  }
+}
+
+async function getIdeClientName(context: CommandContext) {
+  if (!context.agentContext.config.getIdeMode()) {
+    return '';
+  }
+  const ideClient = await IdeClient.getInstance();
+  return ideClient?.getDetectedIdeDisplayName() ?? '';
+}

packages/cli/src/acp/commands/commandRegistry.ts

@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { debugLogger } from '@google/gemini-cli-core';
+import type { Command } from './types.js';
+
+export class CommandRegistry {
+  private readonly commands = new Map<string, Command>();
+
+  register(command: Command) {
+    if (this.commands.has(command.name)) {
+      debugLogger.warn(`Command ${command.name} already registered. Skipping.`);
+      return;
+    }
+
+    this.commands.set(command.name, command);
+
+    for (const subCommand of command.subCommands ?? []) {
+      this.register(subCommand);
+    }
+  }
+
+  get(commandName: string): Command | undefined {
+    return this.commands.get(commandName);
+  }
+
+  getAllCommands(): Command[] {
+    return [...this.commands.values()];
+  }
+}

packages/cli/src/acp/commands/extensions.test.ts

@@ -0,0 +1,100 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import type { CommandContext } from './types.js';
+import {
+  DisableExtensionCommand,
+  UninstallExtensionCommand,
+} from './extensions.js';
+import { ExtensionManager } from '../../config/extension-manager.js';
+
+const mockGetErrorMessage = vi.hoisted(() => vi.fn());
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    getErrorMessage: mockGetErrorMessage,
+  };
+});
+
+vi.mock('../../config/extension-manager.js', () => {
+  class MockExtensionManager {
+    disableExtension = vi.fn(async () => undefined);
+    uninstallExtension = vi.fn(async () => undefined);
+    getExtensions = vi.fn(() => []);
+  }
+
+  return {
+    ExtensionManager: MockExtensionManager,
+    inferInstallMetadata: vi.fn(),
+  };
+});
+
+type TestExtensionManager = InstanceType<typeof ExtensionManager> & {
+  disableExtension: ReturnType<typeof vi.fn>;
+  uninstallExtension: ReturnType<typeof vi.fn>;
+  getExtensions: ReturnType<typeof vi.fn>;
+};
+
+function createExtensionManager(): TestExtensionManager {
+  return new ExtensionManager({} as never) as TestExtensionManager;
+}
+
+function createContext(extensionLoader: unknown): CommandContext {
+  return {
+    agentContext: {
+      config: {
+        getExtensionLoader: vi.fn().mockReturnValue(extensionLoader),
+      },
+    } as unknown as CommandContext['agentContext'],
+    settings: {} as CommandContext['settings'],
+    sendMessage: vi.fn().mockResolvedValue(undefined),
+  };
+}
+
+describe('ACP extensions error paths', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockGetErrorMessage.mockImplementation((error: unknown) =>
+      error instanceof Error ? error.message : String(error),
+    );
+  });
+
+  it('returns error when disabling fails', async () => {
+    const command = new DisableExtensionCommand();
+    const extensionManager = createExtensionManager();
+    extensionManager.disableExtension.mockRejectedValue(
+      new Error('Extension not found.'),
+    );
+    const context = createContext(extensionManager);
+
+    const result = await command.execute(context, ['missing-ext']);
+
+    expect(result).toEqual({
+      name: 'extensions disable',
+      data: 'Failed to disable "missing-ext": Extension not found.',
+    });
+  });
+
+  it('returns error when uninstalling a non-existent extension', async () => {
+    const command = new UninstallExtensionCommand();
+    const extensionManager = createExtensionManager();
+    extensionManager.uninstallExtension.mockRejectedValue(
+      new Error('Extension not found.'),
+    );
+    const context = createContext(extensionManager);
+
+    const result = await command.execute(context, ['non-existent-ext']);
+
+    expect(result).toEqual({
+      name: 'extensions uninstall',
+      data: 'Failed to uninstall extension "non-existent-ext": Extension not found.',
+    });
+  });
+});

packages/cli/src/acp/commands/extensions.ts

@@ -0,0 +1,448 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  listExtensions,
+  type Config,
+  getErrorMessage,
+} from '@google/gemini-cli-core';
+import { SettingScope } from '../../config/settings.js';
+import {
+  ExtensionManager,
+  inferInstallMetadata,
+} from '../../config/extension-manager.js';
+import { McpServerEnablementManager } from '../../config/mcp/mcpServerEnablement.js';
+import { stat } from 'node:fs/promises';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class ExtensionsCommand implements Command {
+  readonly name = 'extensions';
+  readonly description = 'Manage extensions.';
+  readonly subCommands = [
+    new ListExtensionsCommand(),
+    new ExploreExtensionsCommand(),
+    new EnableExtensionCommand(),
+    new DisableExtensionCommand(),
+    new InstallExtensionCommand(),
+    new LinkExtensionCommand(),
+    new UninstallExtensionCommand(),
+    new RestartExtensionCommand(),
+    new UpdateExtensionCommand(),
+  ];
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    return new ListExtensionsCommand().execute(context, _);
+  }
+}
+
+export class ListExtensionsCommand implements Command {
+  readonly name = 'extensions list';
+  readonly description = 'Lists all installed extensions.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensions = listExtensions(context.agentContext.config);
+    const data = extensions.length ? extensions : 'No extensions installed.';
+
+    return { name: this.name, data };
+  }
+}
+
+export class ExploreExtensionsCommand implements Command {
+  readonly name = 'extensions explore';
+  readonly description = 'Explore available extensions.';
+
+  async execute(
+    _context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensionsUrl = 'https://geminicli.com/extensions/';
+    return {
+      name: this.name,
+      data: `View or install available extensions at ${extensionsUrl}`,
+    };
+  }
+}
+
+function getEnableDisableContext(
+  config: Config,
+  args: string[],
+  invocationName: string,
+) {
+  const extensionManager = config.getExtensionLoader();
+  if (!(extensionManager instanceof ExtensionManager)) {
+    return {
+      error: `Cannot ${invocationName} extensions in this environment.`,
+    };
+  }
+
+  if (args.length === 0) {
+    return {
+      error: `Usage: /extensions ${invocationName} <extension> [--scope=<user|workspace|session>]`,
+    };
+  }
+
+  let scope = SettingScope.User;
+  if (args.includes('--scope=workspace') || args.includes('workspace')) {
+    scope = SettingScope.Workspace;
+  } else if (args.includes('--scope=session') || args.includes('session')) {
+    scope = SettingScope.Session;
+  }
+
+  const name = args.filter(
+    (a) =>
+      !a.startsWith('--scope') && !['user', 'workspace', 'session'].includes(a),
+  )[0];
+
+  let names: string[] = [];
+  if (name === '--all') {
+    let extensions = extensionManager.getExtensions();
+    if (invocationName === 'enable') {
+      extensions = extensions.filter((ext) => !ext.isActive);
+    }
+    if (invocationName === 'disable') {
+      extensions = extensions.filter((ext) => ext.isActive);
+    }
+    names = extensions.map((ext) => ext.name);
+  } else if (name) {
+    names = [name];
+  } else {
+    return { error: 'No extension name provided.' };
+  }
+
+  return { extensionManager, names, scope };
+}
+
+export class EnableExtensionCommand implements Command {
+  readonly name = 'extensions enable';
+  readonly description = 'Enable an extension.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const enableContext = getEnableDisableContext(
+      context.agentContext.config,
+      args,
+      'enable',
+    );
+    if ('error' in enableContext) {
+      return { name: this.name, data: enableContext.error };
+    }
+
+    const { names, scope, extensionManager } = enableContext;
+    const output: string[] = [];
+
+    for (const name of names) {
+      try {
+        await extensionManager.enableExtension(name, scope);
+        output.push(`Extension "${name}" enabled for scope "${scope}".`);
+
+        const extension = extensionManager
+          .getExtensions()
+          .find((e) => e.name === name);
+
+        if (extension?.mcpServers) {
+          const mcpEnablementManager = McpServerEnablementManager.getInstance();
+          const mcpClientManager =
+            context.agentContext.config.getMcpClientManager();
+          const enabledServers = await mcpEnablementManager.autoEnableServers(
+            Object.keys(extension.mcpServers),
+          );
+
+          if (mcpClientManager && enabledServers.length > 0) {
+            const restartPromises = enabledServers.map((serverName) =>
+              mcpClientManager.restartServer(serverName).catch((error) => {
+                output.push(
+                  `Failed to restart MCP server '${serverName}': ${getErrorMessage(error)}`,
+                );
+              }),
+            );
+            await Promise.all(restartPromises);
+            output.push(`Re-enabled MCP servers: ${enabledServers.join(', ')}`);
+          }
+        }
+      } catch (e) {
+        output.push(`Failed to enable "${name}": ${getErrorMessage(e)}`);
+      }
+    }
+
+    return { name: this.name, data: output.join('\n') || 'No action taken.' };
+  }
+}
+
+export class DisableExtensionCommand implements Command {
+  readonly name = 'extensions disable';
+  readonly description = 'Disable an extension.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const enableContext = getEnableDisableContext(
+      context.agentContext.config,
+      args,
+      'disable',
+    );
+    if ('error' in enableContext) {
+      return { name: this.name, data: enableContext.error };
+    }
+
+    const { names, scope, extensionManager } = enableContext;
+    const output: string[] = [];
+
+    for (const name of names) {
+      try {
+        await extensionManager.disableExtension(name, scope);
+        output.push(`Extension "${name}" disabled for scope "${scope}".`);
+      } catch (e) {
+        output.push(`Failed to disable "${name}": ${getErrorMessage(e)}`);
+      }
+    }
+
+    return { name: this.name, data: output.join('\n') || 'No action taken.' };
+  }
+}
+
+export class InstallExtensionCommand implements Command {
+  readonly name = 'extensions install';
+  readonly description = 'Install an extension from a git repo or local path.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensionLoader = context.agentContext.config.getExtensionLoader();
+    if (!(extensionLoader instanceof ExtensionManager)) {
+      return {
+        name: this.name,
+        data: 'Cannot install extensions in this environment.',
+      };
+    }
+
+    const source = args.join(' ').trim();
+    if (!source) {
+      return { name: this.name, data: `Usage: /extensions install <source>` };
+    }
+
+    if (/[;&|`'"]/.test(source)) {
+      return {
+        name: this.name,
+        data: `Invalid source: contains disallowed characters.`,
+      };
+    }
+
+    try {
+      const installMetadata = await inferInstallMetadata(source);
+      const extension =
+        await extensionLoader.installOrUpdateExtension(installMetadata);
+      return {
+        name: this.name,
+        data: `Extension "${extension.name}" installed successfully.`,
+      };
+    } catch (error) {
+      return {
+        name: this.name,
+        data: `Failed to install extension from "${source}": ${getErrorMessage(error)}`,
+      };
+    }
+  }
+}
+
+export class LinkExtensionCommand implements Command {
+  readonly name = 'extensions link';
+  readonly description = 'Link an extension from a local path.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensionLoader = context.agentContext.config.getExtensionLoader();
+    if (!(extensionLoader instanceof ExtensionManager)) {
+      return {
+        name: this.name,
+        data: 'Cannot link extensions in this environment.',
+      };
+    }
+
+    const sourceFilepath = args.join(' ').trim();
+    if (!sourceFilepath) {
+      return { name: this.name, data: `Usage: /extensions link <source>` };
+    }
+
+    try {
+      await stat(sourceFilepath);
+    } catch {
+      return { name: this.name, data: `Invalid source: ${sourceFilepath}` };
+    }
+
+    try {
+      const extension = await extensionLoader.installOrUpdateExtension({
+        source: sourceFilepath,
+        type: 'link',
+      });
+      return {
+        name: this.name,
+        data: `Extension "${extension.name}" linked successfully.`,
+      };
+    } catch (error) {
+      return {
+        name: this.name,
+        data: `Failed to link extension: ${getErrorMessage(error)}`,
+      };
+    }
+  }
+}
+
+export class UninstallExtensionCommand implements Command {
+  readonly name = 'extensions uninstall';
+  readonly description = 'Uninstall an extension.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensionLoader = context.agentContext.config.getExtensionLoader();
+    if (!(extensionLoader instanceof ExtensionManager)) {
+      return {
+        name: this.name,
+        data: 'Cannot uninstall extensions in this environment.',
+      };
+    }
+
+    const all = args.includes('--all');
+    const names = args.filter((a) => !a.startsWith('--')).map((a) => a.trim());
+
+    if (!all && names.length === 0) {
+      return {
+        name: this.name,
+        data: `Usage: /extensions uninstall <extension-names...>|--all`,
+      };
+    }
+
+    let namesToUninstall: string[] = [];
+    if (all) {
+      namesToUninstall = extensionLoader.getExtensions().map((ext) => ext.name);
+    } else {
+      namesToUninstall = names;
+    }
+
+    if (namesToUninstall.length === 0) {
+      return {
+        name: this.name,
+        data: all ? 'No extensions installed.' : 'No extension name provided.',
+      };
+    }
+
+    const output: string[] = [];
+    for (const extensionName of namesToUninstall) {
+      try {
+        await extensionLoader.uninstallExtension(extensionName, false);
+        output.push(`Extension "${extensionName}" uninstalled successfully.`);
+      } catch (error) {
+        output.push(
+          `Failed to uninstall extension "${extensionName}": ${getErrorMessage(error)}`,
+        );
+      }
+    }
+
+    return { name: this.name, data: output.join('\n') };
+  }
+}
+
+export class RestartExtensionCommand implements Command {
+  readonly name = 'extensions restart';
+  readonly description = 'Restart an extension.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensionLoader = context.agentContext.config.getExtensionLoader();
+    if (!(extensionLoader instanceof ExtensionManager)) {
+      return { name: this.name, data: 'Cannot restart extensions.' };
+    }
+
+    const all = args.includes('--all');
+    const names = all ? null : args.filter((a) => !!a);
+
+    if (!all && names?.length === 0) {
+      return {
+        name: this.name,
+        data: 'Usage: /extensions restart <extension-names>|--all',
+      };
+    }
+
+    let extensionsToRestart = extensionLoader
+      .getExtensions()
+      .filter((e) => e.isActive);
+    if (names) {
+      extensionsToRestart = extensionsToRestart.filter((e) =>
+        names.includes(e.name),
+      );
+    }
+
+    if (extensionsToRestart.length === 0) {
+      return {
+        name: this.name,
+        data: 'No active extensions matched the request.',
+      };
+    }
+
+    const output: string[] = [];
+    for (const extension of extensionsToRestart) {
+      try {
+        await extensionLoader.restartExtension(extension);
+        output.push(`Restarted "${extension.name}".`);
+      } catch (e) {
+        output.push(
+          `Failed to restart "${extension.name}": ${getErrorMessage(e)}`,
+        );
+      }
+    }
+
+    return { name: this.name, data: output.join('\n') };
+  }
+}
+
+export class UpdateExtensionCommand implements Command {
+  readonly name = 'extensions update';
+  readonly description = 'Update an extension.';
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const extensionLoader = context.agentContext.config.getExtensionLoader();
+    if (!(extensionLoader instanceof ExtensionManager)) {
+      return { name: this.name, data: 'Cannot update extensions.' };
+    }
+
+    const all = args.includes('--all');
+    const names = all ? null : args.filter((a) => !!a);
+
+    if (!all && names?.length === 0) {
+      return {
+        name: this.name,
+        data: 'Usage: /extensions update <extension-names>|--all',
+      };
+    }
+
+    return {
+      name: this.name,
+      data: 'Headless extension updating requires internal UI dispatches. Please use `gemini extensions update` directly in the terminal.',
+    };
+  }
+}

packages/cli/src/acp/commands/help.test.ts

@@ -0,0 +1,53 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { HelpCommand } from './help.js';
+import { CommandRegistry } from './commandRegistry.js';
+import type { Command, CommandContext } from './types.js';
+
+describe('HelpCommand', () => {
+  it('returns formatted help text with sorted commands', async () => {
+    const registry = new CommandRegistry();
+
+    const cmdB: Command = {
+      name: 'bravo',
+      description: 'Bravo command',
+      execute: async () => ({ name: 'bravo', data: '' }),
+    };
+
+    const cmdA: Command = {
+      name: 'alpha',
+      description: 'Alpha command',
+      execute: async () => ({ name: 'alpha', data: '' }),
+    };
+
+    registry.register(cmdB);
+    registry.register(cmdA);
+
+    const helpCommand = new HelpCommand(registry);
+
+    const context = {} as CommandContext;
+
+    const response = await helpCommand.execute(context, []);
+
+    expect(response.name).toBe('help');
+
+    const data = response.data as string;
+
+    expect(data).toContain('Gemini CLI Help:');
+    expect(data).toContain('### Basics');
+    expect(data).toContain('### Commands');
+
+    const lines = data.split('\n');
+    const alphaIndex = lines.findIndex((l) => l.includes('/alpha'));
+    const bravoIndex = lines.findIndex((l) => l.includes('/bravo'));
+
+    expect(alphaIndex).toBeLessThan(bravoIndex);
+    expect(alphaIndex).not.toBe(-1);
+    expect(bravoIndex).not.toBe(-1);
+  });
+});

packages/cli/src/acp/commands/help.ts

@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+import type { CommandRegistry } from './commandRegistry.js';
+
+export class HelpCommand implements Command {
+  readonly name = 'help';
+  readonly description = 'Show available commands';
+
+  constructor(private registry: CommandRegistry) {}
+
+  async execute(
+    _context: CommandContext,
+    _args: string[] = [],
+  ): Promise<CommandExecutionResponse> {
+    const commands = this.registry
+      .getAllCommands()
+      .sort((a, b) => a.name.localeCompare(b.name));
+
+    const lines: string[] = [];
+
+    lines.push('Gemini CLI Help:');
+    lines.push('');
+    lines.push('### Basics');
+    lines.push(
+      '- **Add context**: Use `@` to specify files for context (e.g., `@src/myFile.ts`) to target specific files or folders.',
+    );
+    lines.push('');
+
+    lines.push('### Commands');
+    for (const cmd of commands) {
+      if (cmd.description) {
+        lines.push(`- **/${cmd.name}** - ${cmd.description}`);
+      }
+    }
+
+    return {
+      name: this.name,
+      data: lines.join('\n'),
+    };
+  }
+}

packages/cli/src/acp/commands/init.ts

@@ -0,0 +1,62 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import { performInit } from '@google/gemini-cli-core';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class InitCommand implements Command {
+  name = 'init';
+  description = 'Analyzes the project and creates a tailored GEMINI.md file';
+  requiresWorkspace = true;
+
+  async execute(
+    context: CommandContext,
+    _args: string[] = [],
+  ): Promise<CommandExecutionResponse> {
+    const targetDir = context.agentContext.config.getTargetDir();
+    if (!targetDir) {
+      throw new Error('Command requires a workspace.');
+    }
+
+    const geminiMdPath = path.join(targetDir, 'GEMINI.md');
+    const result = performInit(fs.existsSync(geminiMdPath));
+
+    switch (result.type) {
+      case 'message':
+        return {
+          name: this.name,
+          data: result,
+        };
+      case 'submit_prompt':
+        fs.writeFileSync(geminiMdPath, '', 'utf8');
+
+        if (typeof result.content !== 'string') {
+          throw new Error('Init command content must be a string.');
+        }
+
+        // Inform the user since we can't trigger the UI-based interactive agent loop here directly.
+        // We output the prompt text they can use to re-trigger the generation manually,
+        // or just seed the GEMINI.md file as we've done above.
+        return {
+          name: this.name,
+          data: {
+            type: 'message',
+            messageType: 'info',
+            content: `A template GEMINI.md has been created at ${geminiMdPath}.\n\nTo populate it with project context, you can run the following prompt in a new chat:\n\n${result.content}`,
+          },
+        };
+
+      default:
+        throw new Error('Unknown result type from performInit');
+    }
+  }
+}

packages/cli/src/acp/commands/memory.ts

@@ -0,0 +1,142 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  listInboxMemoryPatches,
+  listInboxSkills,
+  listInboxPatches,
+  listMemoryFiles,
+  refreshMemory,
+  showMemory,
+} from '@google/gemini-cli-core';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class MemoryCommand implements Command {
+  readonly name = 'memory';
+  readonly description = 'Manage memory.';
+  readonly subCommands = [
+    new ShowMemoryCommand(),
+    new RefreshMemoryCommand(),
+    new ListMemoryCommand(),
+    new InboxMemoryCommand(),
+  ];
+  readonly requiresWorkspace = true;
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    return new ShowMemoryCommand().execute(context, _);
+  }
+}
+
+export class ShowMemoryCommand implements Command {
+  readonly name = 'memory show';
+  readonly description = 'Shows the current memory contents.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const result = showMemory(context.agentContext.config);
+    return { name: this.name, data: result.content };
+  }
+}
+
+export class RefreshMemoryCommand implements Command {
+  readonly name = 'memory refresh';
+  readonly aliases = ['memory reload'];
+  readonly description = 'Refreshes the memory from the source.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const result = await refreshMemory(context.agentContext.config);
+    return { name: this.name, data: result.content };
+  }
+}
+
+export class ListMemoryCommand implements Command {
+  readonly name = 'memory list';
+  readonly description = 'Lists the paths of the GEMINI.md files in use.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    const result = listMemoryFiles(context.agentContext.config);
+    return { name: this.name, data: result.content };
+  }
+}
+
+export class InboxMemoryCommand implements Command {
+  readonly name = 'memory inbox';
+  readonly description =
+    'Lists memory items extracted from past sessions that are pending review.';
+
+  async execute(
+    context: CommandContext,
+    _: string[],
+  ): Promise<CommandExecutionResponse> {
+    if (!context.agentContext.config.isAutoMemoryEnabled()) {
+      return {
+        name: this.name,
+        data: 'The memory inbox requires Auto Memory. Enable it with: experimental.autoMemory = true in settings.',
+      };
+    }
+
+    const [skills, patches, memoryPatches] = await Promise.all([
+      listInboxSkills(context.agentContext.config),
+      listInboxPatches(context.agentContext.config),
+      listInboxMemoryPatches(context.agentContext.config),
+    ]);
+
+    if (
+      skills.length === 0 &&
+      patches.length === 0 &&
+      memoryPatches.length === 0
+    ) {
+      return { name: this.name, data: 'No items in inbox.' };
+    }
+
+    const lines: string[] = [];
+    for (const s of skills) {
+      const date = s.extractedAt
+        ? ` (extracted: ${new Date(s.extractedAt).toLocaleDateString()})`
+        : '';
+      lines.push(`- **${s.name}**: ${s.description}${date}`);
+    }
+    for (const p of patches) {
+      const targets = p.entries.map((e) => e.targetPath).join(', ');
+      const date = p.extractedAt
+        ? ` (extracted: ${new Date(p.extractedAt).toLocaleDateString()})`
+        : '';
+      lines.push(`- **${p.name}** (update): patches ${targets}${date}`);
+    }
+    for (const memoryPatch of memoryPatches) {
+      const targets = memoryPatch.entries.map((e) => e.targetPath).join(', ');
+      const date = memoryPatch.extractedAt
+        ? ` (latest extract: ${new Date(memoryPatch.extractedAt).toLocaleDateString()})`
+        : '';
+      const sourceCount = memoryPatch.sourceFiles.length;
+      const sourceLabel = sourceCount === 1 ? 'patch' : 'patches';
+      lines.push(
+        `- **${memoryPatch.name}** (${sourceCount} source ${sourceLabel}, ${memoryPatch.entries.length} hunks): targets ${targets}${date}`,
+      );
+    }
+
+    const total = skills.length + patches.length + memoryPatches.length;
+    return {
+      name: this.name,
+      data: `Memory inbox (${total}):\n${lines.join('\n')}`,
+    };
+  }
+}

packages/cli/src/acp/commands/restore.test.ts

@@ -0,0 +1,244 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { RestoreCommand, ListCheckpointsCommand } from './restore.js';
+import * as fs from 'node:fs/promises';
+import {
+  getCheckpointInfoList,
+  getToolCallDataSchema,
+  isNodeError,
+  performRestore,
+} from '@google/gemini-cli-core';
+import type { CommandContext } from './types.js';
+import type { Mock } from 'vitest';
+
+vi.mock('node:fs/promises');
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    getCheckpointInfoList: vi.fn(),
+    getToolCallDataSchema: vi.fn(),
+    isNodeError: vi.fn(),
+    performRestore: vi.fn(),
+  };
+});
+
+describe('RestoreCommand', () => {
+  let context: CommandContext;
+  let restoreCommand: RestoreCommand;
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+    restoreCommand = new RestoreCommand();
+    context = {
+      agentContext: {
+        config: {
+          getCheckpointingEnabled: vi.fn().mockReturnValue(true),
+          storage: {
+            getProjectTempCheckpointsDir: vi
+              .fn()
+              .mockReturnValue('/tmp/checkpoints'),
+          },
+        },
+      },
+      git: {},
+      sendMessage: vi.fn(),
+    } as unknown as CommandContext;
+  });
+
+  it('delegates to list behavior when invoked without args', async () => {
+    const listExecuteSpy = vi
+      .spyOn(ListCheckpointsCommand.prototype, 'execute')
+      .mockResolvedValue({
+        name: 'restore list',
+        data: 'list data',
+      });
+
+    const response = await restoreCommand.execute(context, []);
+
+    expect(listExecuteSpy).toHaveBeenCalledWith(context);
+    expect(response).toEqual({
+      name: 'restore list',
+      data: 'list data',
+    });
+  });
+
+  it('returns checkpointing-disabled message when disabled', async () => {
+    (
+      context.agentContext.config.getCheckpointingEnabled as Mock
+    ).mockReturnValue(false);
+
+    const response = await restoreCommand.execute(context, ['checkpoint1']);
+
+    expect(response.data).toContain('Checkpointing is not enabled');
+  });
+
+  it('returns file-not-found message for missing checkpoint', async () => {
+    const error = new Error('ENOENT');
+    (error as Error & { code: string }).code = 'ENOENT';
+    vi.mocked(fs.readFile).mockRejectedValue(error);
+    vi.mocked(isNodeError).mockReturnValue(true);
+
+    const response = await restoreCommand.execute(context, ['missing']);
+
+    expect(response.data).toBe('File not found: missing.json');
+  });
+
+  it('handles checkpoint filename already ending in .json', async () => {
+    const error = new Error('ENOENT');
+    (error as Error & { code: string }).code = 'ENOENT';
+    vi.mocked(fs.readFile).mockRejectedValue(error);
+    vi.mocked(isNodeError).mockReturnValue(true);
+
+    const response = await restoreCommand.execute(context, ['existing.json']);
+
+    expect(response.data).toBe('File not found: existing.json');
+    expect(fs.readFile).toHaveBeenCalledWith(
+      expect.stringContaining('existing.json'),
+      'utf-8',
+    );
+  });
+
+  it('returns invalid/corrupt checkpoint message when schema parse fails', async () => {
+    vi.mocked(fs.readFile).mockResolvedValue('{"invalid": "data"}');
+    vi.mocked(getToolCallDataSchema).mockReturnValue({
+      safeParse: vi.fn().mockReturnValue({ success: false }),
+    } as unknown as ReturnType<typeof getToolCallDataSchema>);
+
+    const response = await restoreCommand.execute(context, ['invalid']);
+
+    expect(response.data).toBe('Checkpoint file is invalid or corrupted.');
+  });
+
+  it('formats streamed restore results correctly', async () => {
+    vi.mocked(fs.readFile).mockResolvedValue('{"valid": "data"}');
+    vi.mocked(getToolCallDataSchema).mockReturnValue({
+      safeParse: vi
+        .fn()
+        .mockReturnValue({ success: true, data: { some: 'data' } }),
+    } as unknown as ReturnType<typeof getToolCallDataSchema>);
+
+    async function* mockRestoreGenerator() {
+      yield { type: 'message', messageType: 'info', content: 'Restoring...' };
+      yield { type: 'load_history', clientHistory: [{}, {}] };
+      yield { type: 'other', some: 'other' };
+    }
+    vi.mocked(performRestore).mockReturnValue(
+      mockRestoreGenerator() as unknown as ReturnType<typeof performRestore>,
+    );
+
+    const response = await restoreCommand.execute(context, ['valid']);
+
+    expect(response.data).toContain('[INFO] Restoring...');
+    expect(response.data).toContain('Loaded history with 2 messages.');
+    expect(response.data).toContain(
+      'Restored: {"type":"other","some":"other"}',
+    );
+  });
+
+  it('returns generic unexpected error message for non-ENOENT failures', async () => {
+    vi.mocked(fs.readFile).mockRejectedValue(new Error('Random error'));
+    vi.mocked(isNodeError).mockReturnValue(false);
+
+    const response = await restoreCommand.execute(context, ['error']);
+
+    expect(response.data).toContain(
+      'An unexpected error occurred during restore: Error: Random error',
+    );
+  });
+});
+
+describe('ListCheckpointsCommand', () => {
+  let context: CommandContext;
+  let listCommand: ListCheckpointsCommand;
+  let mockReaddir: Mock<(path: string) => Promise<string[]>>;
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+    listCommand = new ListCheckpointsCommand();
+    mockReaddir = vi.mocked(fs.readdir) as unknown as Mock<
+      (path: string) => Promise<string[]>
+    >;
+
+    context = {
+      agentContext: {
+        config: {
+          getCheckpointingEnabled: vi.fn().mockReturnValue(true),
+          storage: {
+            getProjectTempCheckpointsDir: vi
+              .fn()
+              .mockReturnValue('/tmp/checkpoints'),
+          },
+        },
+      },
+    } as unknown as CommandContext;
+  });
+
+  it('returns checkpointing-disabled message when disabled', async () => {
+    (
+      context.agentContext.config.getCheckpointingEnabled as Mock
+    ).mockReturnValue(false);
+
+    const response = await listCommand.execute(context);
+
+    expect(response.data).toContain('Checkpointing is not enabled');
+  });
+
+  it('returns "No checkpoints found." when no .json checkpoints exist', async () => {
+    mockReaddir.mockResolvedValue(['not-a-checkpoint.txt']);
+
+    const response = await listCommand.execute(context);
+
+    expect(response.data).toBe('No checkpoints found.');
+  });
+
+  it('ignores error when mkdir fails', async () => {
+    vi.mocked(fs.mkdir).mockRejectedValue(new Error('mkdir fail'));
+    mockReaddir.mockResolvedValue([]);
+
+    const response = await listCommand.execute(context);
+
+    expect(response.data).toBe('No checkpoints found.');
+    expect(fs.mkdir).toHaveBeenCalled();
+  });
+
+  it('formats checkpoint summary output from checkpoint metadata', async () => {
+    mockReaddir.mockResolvedValue(['cp1.json', 'cp2.json']);
+    vi.mocked(getCheckpointInfoList).mockReturnValue([
+      { messageId: 'id1', checkpoint: 'cp1' },
+      { messageId: 'id2', checkpoint: 'cp2' },
+    ]);
+
+    const response = await listCommand.execute(context);
+
+    expect(response.data).toContain('Available Checkpoints:');
+    // Note: The current implementation of ListCheckpointsCommand incorrectly accesses
+    // fileName, toolName, etc. which don't exist on CheckpointInfo, resulting in 'Unknown'.
+    expect(response.data).toContain('- **Unknown**: Unknown (Status: Unknown)');
+  });
+
+  it('handles empty checkpoint info list', async () => {
+    mockReaddir.mockResolvedValue(['some.json']);
+    vi.mocked(getCheckpointInfoList).mockReturnValue([]);
+
+    const response = await listCommand.execute(context);
+
+    expect(response.data).toBe('Available Checkpoints:\n');
+  });
+
+  it('returns generic unexpected error message on failures', async () => {
+    mockReaddir.mockRejectedValue(new Error('Readdir fail'));
+
+    const response = await listCommand.execute(context);
+
+    expect(response.data).toBe(
+      'An unexpected error occurred while listing checkpoints.',
+    );
+  });
+});

packages/cli/src/acp/commands/restore.ts

@@ -0,0 +1,179 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  getCheckpointInfoList,
+  getToolCallDataSchema,
+  isNodeError,
+  performRestore,
+} from '@google/gemini-cli-core';
+import * as fs from 'node:fs/promises';
+import * as path from 'node:path';
+import type {
+  Command,
+  CommandContext,
+  CommandExecutionResponse,
+} from './types.js';
+
+export class RestoreCommand implements Command {
+  readonly name = 'restore';
+  readonly description =
+    'Restore to a previous checkpoint, or list available checkpoints to restore. This will reset the conversation and file history to the state it was in when the checkpoint was created';
+  readonly requiresWorkspace = true;
+  readonly subCommands = [new ListCheckpointsCommand()];
+
+  async execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse> {
+    const { agentContext: agentContext, git: gitService } = context;
+    const { config } = agentContext;
+    const argsStr = args.join(' ');
+
+    try {
+      if (!argsStr) {
+        return await new ListCheckpointsCommand().execute(context);
+      }
+
+      if (!config.getCheckpointingEnabled()) {
+        return {
+          name: this.name,
+          data: 'Checkpointing is not enabled. Please enable it in your settings (`general.checkpointing.enabled: true`) to use /restore.',
+        };
+      }
+
+      const selectedFile = argsStr.endsWith('.json')
+        ? argsStr
+        : `${argsStr}.json`;
+
+      const checkpointDir = config.storage.getProjectTempCheckpointsDir();
+      const filePath = path.join(checkpointDir, selectedFile);
+
+      let data: string;
+      try {
+        data = await fs.readFile(filePath, 'utf-8');
+      } catch (error) {
+        if (isNodeError(error) && error.code === 'ENOENT') {
+          return {
+            name: this.name,
+            data: `File not found: ${selectedFile}`,
+          };
+        }
+        throw error;
+      }
+
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const toolCallData = JSON.parse(data);
+      const ToolCallDataSchema = getToolCallDataSchema();
+      const parseResult = ToolCallDataSchema.safeParse(toolCallData);
+
+      if (!parseResult.success) {
+        return {
+          name: this.name,
+          data: 'Checkpoint file is invalid or corrupted.',
+        };
+      }
+
+      const restoreResultGenerator = performRestore(
+        parseResult.data,
+        gitService,
+      );
+
+      const restoreResult = [];
+      for await (const result of restoreResultGenerator) {
+        restoreResult.push(result);
+      }
+
+      // Format the result nicely since Zed just dumps data
+      const formattedResult = restoreResult
+        .map((r) => {
+          if (r.type === 'message') {
+            return `[${r.messageType.toUpperCase()}] ${r.content}`;
+          } else if (r.type === 'load_history') {
+            return `Loaded history with ${r.clientHistory.length} messages.`;
+          }
+          return `Restored: ${JSON.stringify(r)}`;
+        })
+        .join('\n');
+
+      return {
+        name: this.name,
+        data: formattedResult,
+      };
+    } catch (error) {
+      return {
+        name: this.name,
+        data: `An unexpected error occurred during restore: ${error}`,
+      };
+    }
+  }
+}
+
+export class ListCheckpointsCommand implements Command {
+  readonly name = 'restore list';
+  readonly description = 'Lists all available checkpoints.';
+
+  async execute(context: CommandContext): Promise<CommandExecutionResponse> {
+    const { config } = context.agentContext;
+
+    try {
+      if (!config.getCheckpointingEnabled()) {
+        return {
+          name: this.name,
+          data: 'Checkpointing is not enabled. Please enable it in your settings (`general.checkpointing.enabled: true`) to use /restore.',
+        };
+      }
+
+      const checkpointDir = config.storage.getProjectTempCheckpointsDir();
+      try {
+        await fs.mkdir(checkpointDir, { recursive: true });
+      } catch {
+        // Ignore
+      }
+
+      const files = await fs.readdir(checkpointDir);
+      const jsonFiles = files.filter((file) => file.endsWith('.json'));
+
+      if (jsonFiles.length === 0) {
+        return { name: this.name, data: 'No checkpoints found.' };
+      }
+
+      const checkpointFiles = new Map<string, string>();
+      for (const file of jsonFiles) {
+        const filePath = path.join(checkpointDir, file);
+        const data = await fs.readFile(filePath, 'utf-8');
+        checkpointFiles.set(file, data);
+      }
+
+      const checkpointInfoList = getCheckpointInfoList(checkpointFiles);
+
+      const formatted = checkpointInfoList
+        .map((info) => {
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          const i = info as Record<string, any>;
+          const fileName = String(i['fileName'] || 'Unknown');
+          const toolName = String(i['toolName'] || 'Unknown');
+          const status = String(i['status'] || 'Unknown');
+          const timestamp = new Date(
+            Number(i['timestamp']) || 0,
+          ).toLocaleString();
+
+          return `- **${fileName}**: ${toolName} (Status: ${status}) [${timestamp}]`;
+        })
+        .join('\n');
+
+      return {
+        name: this.name,
+        data: `Available Checkpoints:\n${formatted}`,
+      };
+    } catch {
+      return {
+        name: this.name,
+        data: 'An unexpected error occurred while listing checkpoints.',
+      };
+    }
+  }
+}

packages/cli/src/acp/commands/types.ts

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { AgentLoopContext, GitService } from '@google/gemini-cli-core';
+import type { LoadedSettings } from '../../config/settings.js';
+
+export interface CommandContext {
+  agentContext: AgentLoopContext;
+  settings: LoadedSettings;
+  git?: GitService;
+  sendMessage: (text: string) => Promise<void>;
+}
+
+export interface CommandArgument {
+  readonly name: string;
+  readonly description: string;
+  readonly isRequired?: boolean;
+}
+
+export interface Command {
+  readonly name: string;
+  readonly aliases?: string[];
+  readonly description: string;
+  readonly arguments?: CommandArgument[];
+  readonly subCommands?: Command[];
+  readonly requiresWorkspace?: boolean;
+
+  execute(
+    context: CommandContext,
+    args: string[],
+  ): Promise<CommandExecutionResponse>;
+}
+
+export interface CommandExecutionResponse {
+  readonly name: string;
+  readonly data: unknown;
+}

packages/cli/src/commands/extensions.test.tsx

@@ -0,0 +1,92 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi } from 'vitest';
+import { extensionsCommand } from './extensions.js';
+
+// Mock subcommands
+vi.mock('./extensions/install.js', () => ({
+  installCommand: { command: 'install' },
+}));
+vi.mock('./extensions/uninstall.js', () => ({
+  uninstallCommand: { command: 'uninstall' },
+}));
+vi.mock('./extensions/list.js', () => ({ listCommand: { command: 'list' } }));
+vi.mock('./extensions/update.js', () => ({
+  updateCommand: { command: 'update' },
+}));
+vi.mock('./extensions/disable.js', () => ({
+  disableCommand: { command: 'disable' },
+}));
+vi.mock('./extensions/enable.js', () => ({
+  enableCommand: { command: 'enable' },
+}));
+vi.mock('./extensions/link.js', () => ({ linkCommand: { command: 'link' } }));
+vi.mock('./extensions/new.js', () => ({ newCommand: { command: 'new' } }));
+vi.mock('./extensions/validate.js', () => ({
+  validateCommand: { command: 'validate' },
+}));
+
+// Mock gemini.js
+vi.mock('../gemini.js', () => ({
+  initializeOutputListenersAndFlush: vi.fn(),
+}));
+
+describe('extensionsCommand', () => {
+  it('should have correct command and aliases', () => {
+    expect(extensionsCommand.command).toBe('extensions <command>');
+    expect(extensionsCommand.aliases).toEqual(['extension']);
+    expect(extensionsCommand.describe).toBe('Manage Gemini CLI extensions.');
+  });
+
+  it('should register all subcommands in builder', () => {
+    const mockYargs = {
+      middleware: vi.fn().mockReturnThis(),
+      command: vi.fn().mockReturnThis(),
+      demandCommand: vi.fn().mockReturnThis(),
+      version: vi.fn().mockReturnThis(),
+    };
+
+    // @ts-expect-error - Mocking yargs
+    extensionsCommand.builder(mockYargs);
+
+    expect(mockYargs.middleware).toHaveBeenCalled();
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'install' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'uninstall' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'list' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'update' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'disable' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'enable' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'link' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'new' }),
+    );
+    expect(mockYargs.command).toHaveBeenCalledWith(
+      expect.objectContaining({ command: 'validate' }),
+    );
+    expect(mockYargs.demandCommand).toHaveBeenCalledWith(1, expect.any(String));
+    expect(mockYargs.version).toHaveBeenCalledWith(false);
+  });
+
+  it('should have a handler that does nothing', () => {
+    // @ts-expect-error - Handler doesn't take arguments in this case
+    expect(extensionsCommand.handler()).toBeUndefined();
+  });
+});

packages/cli/src/commands/extensions.tsx

@@ -0,0 +1,47 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { CommandModule } from 'yargs';
+import { installCommand } from './extensions/install.js';
+import { uninstallCommand } from './extensions/uninstall.js';
+import { listCommand } from './extensions/list.js';
+import { updateCommand } from './extensions/update.js';
+import { disableCommand } from './extensions/disable.js';
+import { enableCommand } from './extensions/enable.js';
+import { linkCommand } from './extensions/link.js';
+import { newCommand } from './extensions/new.js';
+import { validateCommand } from './extensions/validate.js';
+import { configureCommand } from './extensions/configure.js';
+import { initializeOutputListenersAndFlush } from '../gemini.js';
+import { defer } from '../deferred.js';
+
+export const extensionsCommand: CommandModule = {
+  command: 'extensions <command>',
+  aliases: ['extension'],
+  describe: 'Manage Gemini CLI extensions.',
+  builder: (yargs) =>
+    yargs
+      .middleware((argv) => {
+        initializeOutputListenersAndFlush();
+        argv['isCommand'] = true;
+      })
+      .command(defer(installCommand, 'extensions'))
+      .command(defer(uninstallCommand, 'extensions'))
+      .command(defer(listCommand, 'extensions'))
+      .command(defer(updateCommand, 'extensions'))
+      .command(defer(disableCommand, 'extensions'))
+      .command(defer(enableCommand, 'extensions'))
+      .command(defer(linkCommand, 'extensions'))
+      .command(defer(newCommand, 'extensions'))
+      .command(defer(validateCommand, 'extensions'))
+      .command(defer(configureCommand, 'extensions'))
+      .demandCommand(1, 'You need at least one command before continuing.')
+      .version(false),
+  handler: () => {
+    // This handler is not called when a subcommand is provided.
+    // Yargs will show the help menu.
+  },
+};

packages/cli/src/commands/extensions/configure.test.ts

@@ -0,0 +1,290 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+import {
+  describe,
+  it,
+  expect,
+  vi,
+  beforeEach,
+  afterEach,
+  type Mock,
+} from 'vitest';
+import { configureCommand } from './configure.js';
+import yargs from 'yargs';
+import { debugLogger } from '@google/gemini-cli-core';
+import {
+  updateSetting,
+  getScopedEnvContents,
+  type ExtensionSetting,
+} from '../../config/extensions/extensionSettings.js';
+import { cleanupTmpDir } from '@google/gemini-cli-test-utils';
+import prompts from 'prompts';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import * as path from 'node:path';
+
+const { mockExtensionManager, mockGetExtensionManager, mockLoadSettings } =
+  vi.hoisted(() => {
+    const extensionManager = {
+      loadExtensionConfig: vi.fn(),
+      getExtensions: vi.fn(),
+      loadExtensions: vi.fn(),
+      getSettings: vi.fn(),
+    };
+    return {
+      mockExtensionManager: extensionManager,
+      mockGetExtensionManager: vi.fn(),
+      mockLoadSettings: vi.fn().mockReturnValue({ merged: {} }),
+    };
+  });
+
+vi.mock('../../config/extension-manager.js', () => ({
+  ExtensionManager: vi.fn().mockImplementation(() => mockExtensionManager),
+}));
+
+vi.mock('../../config/extensions/extensionSettings.js', () => ({
+  updateSetting: vi.fn(),
+  promptForSetting: vi.fn(),
+  getScopedEnvContents: vi.fn(),
+  ExtensionSettingScope: {
+    USER: 'user',
+    WORKSPACE: 'workspace',
+  },
+}));
+
+vi.mock('../utils.js', () => ({
+  exitCli: vi.fn(),
+}));
+
+vi.mock('./utils.js', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('./utils.js')>();
+  return {
+    ...actual,
+    getExtensionManager: mockGetExtensionManager,
+  };
+});
+
+vi.mock('prompts');
+
+vi.mock('../../config/extensions/consent.js', () => ({
+  requestConsentNonInteractive: vi.fn(),
+}));
+
+import { ExtensionManager } from '../../config/extension-manager.js';
+
+vi.mock('../../config/settings.js', () => ({
+  loadSettings: mockLoadSettings,
+}));
+
+describe('extensions configure command', () => {
+  let tempWorkspaceDir: string;
+
+  beforeEach(() => {
+    vi.spyOn(debugLogger, 'log');
+    vi.spyOn(debugLogger, 'error');
+    vi.clearAllMocks();
+
+    tempWorkspaceDir = fs.mkdtempSync(
+      path.join(os.tmpdir(), 'gemini-cli-test-workspace-'),
+    );
+    vi.spyOn(process, 'cwd').mockReturnValue(tempWorkspaceDir);
+    // Default behaviors
+    mockLoadSettings.mockReturnValue({ merged: {} });
+    mockGetExtensionManager.mockResolvedValue(mockExtensionManager);
+    (ExtensionManager as unknown as Mock).mockImplementation(
+      () => mockExtensionManager,
+    );
+  });
+
+  afterEach(async () => {
+    await cleanupTmpDir(tempWorkspaceDir);
+    vi.restoreAllMocks();
+  });
+
+  const runCommand = async (command: string) => {
+    const parser = yargs().command(configureCommand).help(false).version(false);
+    await parser.parse(command);
+  };
+
+  const setupExtension = (
+    name: string,
+    settings: Array<Partial<ExtensionSetting>> = [],
+    id = 'test-id',
+    path = '/test/path',
+  ) => {
+    const extension = { name, path, id };
+
+    mockExtensionManager.getExtensions.mockReturnValue([extension]);
+    mockExtensionManager.loadExtensionConfig.mockResolvedValue({
+      name,
+      settings,
+    });
+    return extension;
+  };
+
+  describe('Specific setting configuration', () => {
+    it('should configure a specific setting', async () => {
+      setupExtension('test-ext', [
+        { name: 'Test Setting', envVar: 'TEST_VAR' },
+      ]);
+      (updateSetting as Mock).mockResolvedValue(undefined);
+
+      await runCommand('config test-ext TEST_VAR');
+
+      expect(updateSetting).toHaveBeenCalledWith(
+        expect.objectContaining({ name: 'test-ext' }),
+        'test-id',
+        'TEST_VAR',
+        expect.any(Function),
+        'user',
+        tempWorkspaceDir,
+      );
+    });
+
+    it('should handle missing extension', async () => {
+      mockExtensionManager.getExtensions.mockReturnValue([]);
+
+      await runCommand('config missing-ext TEST_VAR');
+
+      expect(updateSetting).not.toHaveBeenCalled();
+    });
+
+    it('should reject invalid extension names', async () => {
+      await runCommand('config ../invalid TEST_VAR');
+      expect(debugLogger.error).toHaveBeenCalledWith(
+        expect.stringContaining('Invalid extension name'),
+      );
+
+      await runCommand('config ext/with/slash TEST_VAR');
+      expect(debugLogger.error).toHaveBeenCalledWith(
+        expect.stringContaining('Invalid extension name'),
+      );
+    });
+  });
+
+  describe('Extension configuration (all settings)', () => {
+    it('should configure all settings for an extension', async () => {
+      const settings = [{ name: 'Setting 1', envVar: 'VAR_1' }];
+      setupExtension('test-ext', settings);
+      (getScopedEnvContents as Mock).mockResolvedValue({});
+      (updateSetting as Mock).mockResolvedValue(undefined);
+
+      await runCommand('config test-ext');
+
+      expect(debugLogger.log).toHaveBeenCalledWith(
+        'Configuring settings for "test-ext"...',
+      );
+      expect(updateSetting).toHaveBeenCalledWith(
+        expect.objectContaining({ name: 'test-ext' }),
+        'test-id',
+        'VAR_1',
+        expect.any(Function),
+        'user',
+        tempWorkspaceDir,
+      );
+    });
+
+    it('should verify overwrite if setting is already set', async () => {
+      const settings = [{ name: 'Setting 1', envVar: 'VAR_1' }];
+      setupExtension('test-ext', settings);
+      (getScopedEnvContents as Mock).mockImplementation(
+        async (_config, _id, scope) => {
+          if (scope === 'user') return { VAR_1: 'existing' };
+          return {};
+        },
+      );
+      (prompts as unknown as Mock).mockResolvedValue({ confirm: true });
+      (updateSetting as Mock).mockResolvedValue(undefined);
+
+      await runCommand('config test-ext');
+
+      expect(prompts).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: 'confirm',
+          message: expect.stringContaining('is already set. Overwrite?'),
+        }),
+      );
+      expect(updateSetting).toHaveBeenCalled();
+    });
+
+    it('should note if setting is configured in workspace', async () => {
+      const settings = [{ name: 'Setting 1', envVar: 'VAR_1' }];
+      setupExtension('test-ext', settings);
+      (getScopedEnvContents as Mock).mockImplementation(
+        async (_config, _id, scope) => {
+          if (scope === 'workspace') return { VAR_1: 'workspace_value' };
+          return {};
+        },
+      );
+      (updateSetting as Mock).mockResolvedValue(undefined);
+
+      await runCommand('config test-ext');
+
+      expect(debugLogger.log).toHaveBeenCalledWith(
+        expect.stringContaining('is already configured in the workspace scope'),
+      );
+    });
+
+    it('should skip update if user denies overwrite', async () => {
+      const settings = [{ name: 'Setting 1', envVar: 'VAR_1' }];
+      setupExtension('test-ext', settings);
+      (getScopedEnvContents as Mock).mockResolvedValue({ VAR_1: 'existing' });
+      (prompts as unknown as Mock).mockResolvedValue({ confirm: false });
+
+      await runCommand('config test-ext');
+
+      expect(prompts).toHaveBeenCalled();
+      expect(updateSetting).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('Configure all extensions', () => {
+    it('should configure settings for all installed extensions', async () => {
+      const ext1 = {
+        name: 'ext1',
+        path: '/p1',
+        id: 'id1',
+        settings: [{ envVar: 'V1' }],
+      };
+      const ext2 = {
+        name: 'ext2',
+        path: '/p2',
+        id: 'id2',
+        settings: [{ envVar: 'V2' }],
+      };
+      mockExtensionManager.getExtensions.mockReturnValue([ext1, ext2]);
+
+      mockExtensionManager.loadExtensionConfig.mockImplementation(
+        async (path) => {
+          if (path === '/p1')
+            return { name: 'ext1', settings: [{ name: 'S1', envVar: 'V1' }] };
+          if (path === '/p2')
+            return { name: 'ext2', settings: [{ name: 'S2', envVar: 'V2' }] };
+          return null;
+        },
+      );
+
+      (getScopedEnvContents as Mock).mockResolvedValue({});
+      (updateSetting as Mock).mockResolvedValue(undefined);
+
+      await runCommand('config');
+
+      expect(debugLogger.log).toHaveBeenCalledWith(
+        expect.stringContaining('Configuring settings for "ext1"'),
+      );
+      expect(debugLogger.log).toHaveBeenCalledWith(
+        expect.stringContaining('Configuring settings for "ext2"'),
+      );
+      expect(updateSetting).toHaveBeenCalledTimes(2);
+    });
+
+    it('should log if no extensions installed', async () => {
+      mockExtensionManager.getExtensions.mockReturnValue([]);
+      await runCommand('config');
+      expect(debugLogger.log).toHaveBeenCalledWith('No extensions installed.');
+    });
+  });
+});

packages/cli/src/commands/extensions/configure.ts

@@ -0,0 +1,98 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import type { CommandModule } from 'yargs';
+import type { ExtensionSettingScope } from '../../config/extensions/extensionSettings.js';
+import {
+  configureAllExtensions,
+  configureExtension,
+  configureSpecificSetting,
+  getExtensionManager,
+} from './utils.js';
+import { loadSettings } from '../../config/settings.js';
+import { coreEvents, debugLogger } from '@google/gemini-cli-core';
+import { exitCli } from '../utils.js';
+
+interface ConfigureArgs {
+  name?: string;
+  setting?: string;
+  scope: string;
+}
+
+export const configureCommand: CommandModule<object, ConfigureArgs> = {
+  command: 'config [name] [setting]',
+  describe: 'Configure extension settings.',
+  builder: (yargs) =>
+    yargs
+      .positional('name', {
+        describe: 'Name of the extension to configure.',
+        type: 'string',
+      })
+      .positional('setting', {
+        describe: 'The specific setting to configure (name or env var).',
+        type: 'string',
+      })
+      .option('scope', {
+        describe: 'The scope to set the setting in.',
+        type: 'string',
+        choices: ['user', 'workspace'],
+        default: 'user',
+      }),
+  handler: async (args) => {
+    const { name, setting, scope } = args;
+    const settings = loadSettings(process.cwd()).merged;
+
+    if (!(settings.experimental?.extensionConfig ?? true)) {
+      coreEvents.emitFeedback(
+        'error',
+        'Extension configuration is currently disabled. Enable it by setting "experimental.extensionConfig" to true.',
+      );
+      await exitCli();
+      return;
+    }
+
+    if (name) {
+      if (name.includes('/') || name.includes('\\') || name.includes('..')) {
+        debugLogger.error(
+          'Invalid extension name. Names cannot contain path separators or "..".',
+        );
+        return;
+      }
+    }
+
+    const extensionManager = await getExtensionManager();
+
+    // Case 1: Configure specific setting for an extension
+    if (name && setting) {
+      await configureSpecificSetting(
+        extensionManager,
+        name,
+        setting,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+        scope as ExtensionSettingScope,
+      );
+    }
+    // Case 2: Configure all settings for an extension
+    else if (name) {
+      await configureExtension(
+        extensionManager,
+        name,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+        scope as ExtensionSettingScope,
+      );
+    }
+    // Case 3: Configure all extensions
+    else {
+      await configureAllExtensions(
+        extensionManager,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+        scope as ExtensionSettingScope,
+      );
+    }
+
+    await exitCli();
+  },
+};

packages/cli/src/commands/extensions/disable.test.ts

@@ -0,0 +1,250 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  vi,
+  describe,
+  it,
+  expect,
+  beforeEach,
+  afterEach,
+  type Mock,
+} from 'vitest';
+import { format } from 'node:util';
+import { type Argv } from 'yargs';
+import { handleDisable, disableCommand } from './disable.js';
+import { ExtensionManager } from '../../config/extension-manager.js';
+import {
+  loadSettings,
+  SettingScope,
+  type LoadedSettings,
+} from '../../config/settings.js';
+import { getErrorMessage } from '@google/gemini-cli-core';
+
+// Mock dependencies
+const emitConsoleLog = vi.hoisted(() => vi.fn());
+const debugLogger = vi.hoisted(() => ({
+  log: vi.fn((message, ...args) => {
+    emitConsoleLog('log', format(message, ...args));
+  }),
+  error: vi.fn((message, ...args) => {
+    emitConsoleLog('error', format(message, ...args));
+  }),
+}));
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    coreEvents: {
+      emitConsoleLog,
+    },
+    debugLogger,
+    getErrorMessage: vi.fn(),
+  };
+});
+
+vi.mock('../../config/extension-manager.js');
+vi.mock('../../config/settings.js');
+vi.mock('../../config/extensions/consent.js', () => ({
+  requestConsentNonInteractive: vi.fn(),
+}));
+vi.mock('../../config/extensions/extensionSettings.js', () => ({
+  promptForSetting: vi.fn(),
+}));
+vi.mock('../utils.js', () => ({
+  exitCli: vi.fn(),
+}));
+
+describe('extensions disable command', () => {
+  const mockLoadSettings = vi.mocked(loadSettings);
+  const mockGetErrorMessage = vi.mocked(getErrorMessage);
+  const mockExtensionManager = vi.mocked(ExtensionManager);
+
+  beforeEach(async () => {
+    vi.clearAllMocks();
+    mockLoadSettings.mockReturnValue({
+      merged: {},
+    } as unknown as LoadedSettings);
+    mockExtensionManager.prototype.loadExtensions = vi
+      .fn()
+      .mockResolvedValue(undefined);
+    mockExtensionManager.prototype.disableExtension = vi
+      .fn()
+      .mockResolvedValue(undefined);
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  describe('handleDisable', () => {
+    it.each([
+      {
+        name: 'my-extension',
+        scope: undefined,
+        expectedScope: SettingScope.User,
+        expectedLog:
+          'Extension "my-extension" successfully disabled for scope "undefined".',
+      },
+      {
+        name: 'my-extension',
+        scope: 'user',
+        expectedScope: SettingScope.User,
+        expectedLog:
+          'Extension "my-extension" successfully disabled for scope "user".',
+      },
+      {
+        name: 'my-extension',
+        scope: 'workspace',
+        expectedScope: SettingScope.Workspace,
+        expectedLog:
+          'Extension "my-extension" successfully disabled for scope "workspace".',
+      },
+    ])(
+      'should disable an extension in the $expectedScope scope when scope is $scope',
+      async ({ name, scope, expectedScope, expectedLog }) => {
+        const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+        await handleDisable({ name, scope });
+        expect(mockExtensionManager).toHaveBeenCalledWith(
+          expect.objectContaining({
+            workspaceDir: '/test/dir',
+          }),
+        );
+        expect(
+          mockExtensionManager.prototype.loadExtensions,
+        ).toHaveBeenCalled();
+        expect(
+          mockExtensionManager.prototype.disableExtension,
+        ).toHaveBeenCalledWith(name, expectedScope);
+        expect(emitConsoleLog).toHaveBeenCalledWith('log', expectedLog);
+        mockCwd.mockRestore();
+      },
+    );
+
+    it('should log an error message and exit with code 1 when extension disabling fails', async () => {
+      const mockProcessExit = vi
+        .spyOn(process, 'exit')
+        .mockImplementation((() => {}) as (
+          code?: string | number | null | undefined,
+        ) => never);
+      const error = new Error('Disable failed');
+      (
+        mockExtensionManager.prototype.disableExtension as Mock
+      ).mockRejectedValue(error);
+      mockGetErrorMessage.mockReturnValue('Disable failed message');
+      await handleDisable({ name: 'my-extension' });
+      expect(emitConsoleLog).toHaveBeenCalledWith(
+        'error',
+        'Disable failed message',
+      );
+      expect(mockProcessExit).toHaveBeenCalledWith(1);
+      mockProcessExit.mockRestore();
+    });
+  });
+
+  describe('disableCommand', () => {
+    const command = disableCommand;
+
+    it('should have correct command and describe', () => {
+      expect(command.command).toBe('disable [--scope] <name>');
+      expect(command.describe).toBe('Disables an extension.');
+    });
+
+    describe('builder', () => {
+      interface MockYargs {
+        positional: Mock;
+        option: Mock;
+        check: Mock;
+      }
+
+      let yargsMock: MockYargs;
+
+      beforeEach(() => {
+        yargsMock = {
+          positional: vi.fn().mockReturnThis(),
+          option: vi.fn().mockReturnThis(),
+          check: vi.fn().mockReturnThis(),
+        };
+      });
+
+      it('should configure positional and option arguments', () => {
+        (command.builder as (yargs: Argv) => Argv)(
+          yargsMock as unknown as Argv,
+        );
+        expect(yargsMock.positional).toHaveBeenCalledWith('name', {
+          describe: 'The name of the extension to disable.',
+          type: 'string',
+        });
+        expect(yargsMock.option).toHaveBeenCalledWith('scope', {
+          describe: 'The scope to disable the extension in.',
+          type: 'string',
+          default: SettingScope.User,
+        });
+        expect(yargsMock.check).toHaveBeenCalled();
+      });
+
+      it('check function should throw for invalid scope', () => {
+        (command.builder as (yargs: Argv) => Argv)(
+          yargsMock as unknown as Argv,
+        );
+        const checkCallback = yargsMock.check.mock.calls[0][0];
+        const expectedError = `Invalid scope: invalid. Please use one of ${Object.values(
+          SettingScope,
+        )
+          .map((s) => s.toLowerCase())
+          .join(', ')}.`;
+        expect(() => checkCallback({ scope: 'invalid' })).toThrow(
+          expectedError,
+        );
+      });
+
+      it.each(['user', 'workspace', 'USER', 'WorkSpace'])(
+        'check function should return true for valid scope "%s"',
+        (scope) => {
+          (command.builder as (yargs: Argv) => Argv)(
+            yargsMock as unknown as Argv,
+          );
+          const checkCallback = yargsMock.check.mock.calls[0][0];
+          expect(checkCallback({ scope })).toBe(true);
+        },
+      );
+    });
+
+    it('handler should trigger extension disabling', async () => {
+      const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+      interface TestArgv {
+        name: string;
+        scope: string;
+        [key: string]: unknown;
+      }
+      const argv: TestArgv = {
+        name: 'test-ext',
+        scope: 'workspace',
+        _: [],
+        $0: '',
+      };
+      await (command.handler as unknown as (args: TestArgv) => Promise<void>)(
+        argv,
+      );
+      expect(mockExtensionManager).toHaveBeenCalledWith(
+        expect.objectContaining({
+          workspaceDir: '/test/dir',
+        }),
+      );
+      expect(mockExtensionManager.prototype.loadExtensions).toHaveBeenCalled();
+      expect(
+        mockExtensionManager.prototype.disableExtension,
+      ).toHaveBeenCalledWith('test-ext', SettingScope.Workspace);
+      expect(emitConsoleLog).toHaveBeenCalledWith(
+        'log',
+        'Extension "test-ext" successfully disabled for scope "workspace".',
+      );
+      mockCwd.mockRestore();
+    });
+  });
+});

packages/cli/src/commands/extensions/disable.ts

@@ -0,0 +1,88 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { type CommandModule } from 'yargs';
+import { loadSettings, SettingScope } from '../../config/settings.js';
+import { debugLogger, getErrorMessage } from '@google/gemini-cli-core';
+import { ExtensionManager } from '../../config/extension-manager.js';
+import { requestConsentNonInteractive } from '../../config/extensions/consent.js';
+import { promptForSetting } from '../../config/extensions/extensionSettings.js';
+import { exitCli } from '../utils.js';
+
+interface DisableArgs {
+  name: string;
+  scope?: string;
+}
+
+export async function handleDisable(args: DisableArgs) {
+  const workspaceDir = process.cwd();
+  const extensionManager = new ExtensionManager({
+    workspaceDir,
+    requestConsent: requestConsentNonInteractive,
+    requestSetting: promptForSetting,
+    settings: loadSettings(workspaceDir).merged,
+  });
+  await extensionManager.loadExtensions();
+
+  try {
+    if (args.scope?.toLowerCase() === 'workspace') {
+      await extensionManager.disableExtension(
+        args.name,
+        SettingScope.Workspace,
+      );
+    } else {
+      await extensionManager.disableExtension(args.name, SettingScope.User);
+    }
+    debugLogger.log(
+      `Extension "${args.name}" successfully disabled for scope "${args.scope}".`,
+    );
+  } catch (error) {
+    debugLogger.error(getErrorMessage(error));
+    process.exit(1);
+  }
+}
+
+export const disableCommand: CommandModule = {
+  command: 'disable [--scope] <name>',
+  describe: 'Disables an extension.',
+  builder: (yargs) =>
+    yargs
+      .positional('name', {
+        describe: 'The name of the extension to disable.',
+        type: 'string',
+      })
+      .option('scope', {
+        describe: 'The scope to disable the extension in.',
+        type: 'string',
+        default: SettingScope.User,
+      })
+      .check((argv) => {
+        if (
+          argv.scope &&
+          !Object.values(SettingScope)
+            .map((s) => s.toLowerCase())
+            .includes(argv.scope.toLowerCase())
+        ) {
+          throw new Error(
+            `Invalid scope: ${argv.scope}. Please use one of ${Object.values(
+              SettingScope,
+            )
+              .map((s) => s.toLowerCase())
+              .join(', ')}.`,
+          );
+        }
+        return true;
+      }),
+  handler: async (argv) => {
+    await handleDisable({
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      name: argv['name'] as string,
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      scope: argv['scope'] as string,
+    });
+    await exitCli();
+  },
+};

packages/cli/src/commands/extensions/enable.test.ts

@@ -0,0 +1,280 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  vi,
+  describe,
+  it,
+  expect,
+  beforeEach,
+  afterEach,
+  type Mock,
+} from 'vitest';
+import { format } from 'node:util';
+import { type Argv } from 'yargs';
+import { handleEnable, enableCommand } from './enable.js';
+import { ExtensionManager } from '../../config/extension-manager.js';
+import {
+  loadSettings,
+  SettingScope,
+  type LoadedSettings,
+} from '../../config/settings.js';
+import { FatalConfigError } from '@google/gemini-cli-core';
+
+// Mock dependencies
+const emitConsoleLog = vi.hoisted(() => vi.fn());
+const debugLogger = vi.hoisted(() => ({
+  log: vi.fn((message, ...args) => {
+    emitConsoleLog('log', format(message, ...args));
+  }),
+  error: vi.fn((message, ...args) => {
+    emitConsoleLog('error', format(message, ...args));
+  }),
+}));
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...actual,
+    coreEvents: {
+      emitConsoleLog,
+    },
+    debugLogger,
+    getErrorMessage: vi.fn((error: { message: string }) => error.message),
+    FatalConfigError: class extends Error {
+      constructor(message: string) {
+        super(message);
+        this.name = 'FatalConfigError';
+      }
+    },
+  };
+});
+
+vi.mock('../../config/extension-manager.js');
+vi.mock('../../config/settings.js');
+vi.mock('../../config/extensions/consent.js');
+vi.mock('../../config/extensions/extensionSettings.js');
+vi.mock('../utils.js', () => ({
+  exitCli: vi.fn(),
+}));
+
+const mockEnablementInstance = vi.hoisted(() => ({
+  getDisplayState: vi.fn(),
+  enable: vi.fn(),
+  clearSessionDisable: vi.fn(),
+  autoEnableServers: vi.fn(),
+}));
+vi.mock('../../config/mcp/mcpServerEnablement.js', () => ({
+  McpServerEnablementManager: {
+    getInstance: () => mockEnablementInstance,
+  },
+}));
+
+describe('extensions enable command', () => {
+  const mockLoadSettings = vi.mocked(loadSettings);
+  const mockExtensionManager = vi.mocked(ExtensionManager);
+
+  beforeEach(async () => {
+    vi.clearAllMocks();
+    mockLoadSettings.mockReturnValue({
+      merged: {},
+    } as unknown as LoadedSettings);
+    mockExtensionManager.prototype.loadExtensions = vi
+      .fn()
+      .mockResolvedValue(undefined);
+    mockExtensionManager.prototype.enableExtension = vi.fn();
+    mockExtensionManager.prototype.getExtensions = vi.fn().mockReturnValue([]);
+    mockEnablementInstance.getDisplayState.mockReset();
+    mockEnablementInstance.enable.mockReset();
+    mockEnablementInstance.clearSessionDisable.mockReset();
+    mockEnablementInstance.autoEnableServers.mockReset();
+    mockEnablementInstance.autoEnableServers.mockResolvedValue([]);
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  describe('handleEnable', () => {
+    it.each([
+      {
+        name: 'my-extension',
+        scope: undefined,
+        expectedScope: SettingScope.User,
+        expectedLog:
+          'Extension "my-extension" successfully enabled in all scopes.',
+      },
+      {
+        name: 'my-extension',
+        scope: 'workspace',
+        expectedScope: SettingScope.Workspace,
+        expectedLog:
+          'Extension "my-extension" successfully enabled for scope "workspace".',
+      },
+    ])(
+      'should enable an extension in the $expectedScope scope when scope is $scope',
+      async ({ name, scope, expectedScope, expectedLog }) => {
+        const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+        await handleEnable({ name, scope });
+
+        expect(mockExtensionManager).toHaveBeenCalledWith(
+          expect.objectContaining({
+            workspaceDir: '/test/dir',
+          }),
+        );
+        expect(
+          mockExtensionManager.prototype.loadExtensions,
+        ).toHaveBeenCalled();
+        expect(
+          mockExtensionManager.prototype.enableExtension,
+        ).toHaveBeenCalledWith(name, expectedScope);
+        expect(emitConsoleLog).toHaveBeenCalledWith('log', expectedLog);
+        mockCwd.mockRestore();
+      },
+    );
+
+    it('should throw FatalConfigError when extension enabling fails', async () => {
+      const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+      const error = new Error('Enable failed');
+      (
+        mockExtensionManager.prototype.enableExtension as Mock
+      ).mockImplementation(() => {
+        throw error;
+      });
+
+      const promise = handleEnable({ name: 'my-extension' });
+      await expect(promise).rejects.toThrow(FatalConfigError);
+      await expect(promise).rejects.toThrow('Enable failed');
+
+      mockCwd.mockRestore();
+    });
+
+    it('should auto-enable disabled MCP servers for the extension', async () => {
+      const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+      mockEnablementInstance.autoEnableServers.mockResolvedValue([
+        'test-server',
+      ]);
+      mockExtensionManager.prototype.getExtensions = vi
+        .fn()
+        .mockReturnValue([
+          { name: 'my-extension', mcpServers: { 'test-server': {} } },
+        ]);
+
+      await handleEnable({ name: 'my-extension' });
+
+      expect(mockEnablementInstance.autoEnableServers).toHaveBeenCalledWith([
+        'test-server',
+      ]);
+      expect(emitConsoleLog).toHaveBeenCalledWith(
+        'log',
+        expect.stringContaining("MCP server 'test-server' was disabled"),
+      );
+      mockCwd.mockRestore();
+    });
+
+    it('should not log when MCP servers are already enabled', async () => {
+      const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+      mockEnablementInstance.autoEnableServers.mockResolvedValue([]);
+      mockExtensionManager.prototype.getExtensions = vi
+        .fn()
+        .mockReturnValue([
+          { name: 'my-extension', mcpServers: { 'test-server': {} } },
+        ]);
+
+      await handleEnable({ name: 'my-extension' });
+
+      expect(mockEnablementInstance.autoEnableServers).toHaveBeenCalledWith([
+        'test-server',
+      ]);
+      expect(emitConsoleLog).not.toHaveBeenCalledWith(
+        'log',
+        expect.stringContaining("MCP server 'test-server' was disabled"),
+      );
+      mockCwd.mockRestore();
+    });
+  });
+
+  describe('enableCommand', () => {
+    const command = enableCommand;
+
+    it('should have correct command and describe', () => {
+      expect(command.command).toBe('enable [--scope] <name>');
+      expect(command.describe).toBe('Enables an extension.');
+    });
+
+    describe('builder', () => {
+      interface MockYargs {
+        positional: Mock;
+        option: Mock;
+        check: Mock;
+      }
+
+      let yargsMock: MockYargs;
+      beforeEach(() => {
+        yargsMock = {
+          positional: vi.fn().mockReturnThis(),
+          option: vi.fn().mockReturnThis(),
+          check: vi.fn().mockReturnThis(),
+        };
+      });
+
+      it('should configure positional and option arguments', () => {
+        (command.builder as (yargs: Argv) => Argv)(
+          yargsMock as unknown as Argv,
+        );
+        expect(yargsMock.positional).toHaveBeenCalledWith('name', {
+          describe: 'The name of the extension to enable.',
+          type: 'string',
+        });
+        expect(yargsMock.option).toHaveBeenCalledWith('scope', {
+          describe:
+            'The scope to enable the extension in. If not set, will be enabled in all scopes.',
+          type: 'string',
+        });
+        expect(yargsMock.check).toHaveBeenCalled();
+      });
+
+      it('check function should throw for invalid scope', () => {
+        (command.builder as (yargs: Argv) => Argv)(
+          yargsMock as unknown as Argv,
+        );
+        const checkCallback = yargsMock.check.mock.calls[0][0];
+        const expectedError = `Invalid scope: invalid. Please use one of ${Object.values(
+          SettingScope,
+        )
+          .map((s) => s.toLowerCase())
+          .join(', ')}.`;
+        expect(() => checkCallback({ scope: 'invalid' })).toThrow(
+          expectedError,
+        );
+      });
+    });
+
+    it('handler should call handleEnable', async () => {
+      const mockCwd = vi.spyOn(process, 'cwd').mockReturnValue('/test/dir');
+      interface TestArgv {
+        name: string;
+        scope: string;
+        [key: string]: unknown;
+      }
+      const argv: TestArgv = {
+        name: 'test-ext',
+        scope: 'workspace',
+        _: [],
+        $0: '',
+      };
+      await (command.handler as unknown as (args: TestArgv) => Promise<void>)(
+        argv,
+      );
+
+      expect(
+        mockExtensionManager.prototype.enableExtension,
+      ).toHaveBeenCalledWith('test-ext', SettingScope.Workspace);
+      mockCwd.mockRestore();
+    });
+  });
+});

packages/cli/src/commands/extensions/enable.ts

@@ -0,0 +1,115 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { type CommandModule } from 'yargs';
+import { loadSettings, SettingScope } from '../../config/settings.js';
+import { requestConsentNonInteractive } from '../../config/extensions/consent.js';
+import { ExtensionManager } from '../../config/extension-manager.js';
+import {
+  debugLogger,
+  FatalConfigError,
+  getErrorMessage,
+} from '@google/gemini-cli-core';
+import { promptForSetting } from '../../config/extensions/extensionSettings.js';
+import { exitCli } from '../utils.js';
+import { McpServerEnablementManager } from '../../config/mcp/mcpServerEnablement.js';
+
+interface EnableArgs {
+  name: string;
+  scope?: string;
+}
+
+export async function handleEnable(args: EnableArgs) {
+  const workingDir = process.cwd();
+  const extensionManager = new ExtensionManager({
+    workspaceDir: workingDir,
+    requestConsent: requestConsentNonInteractive,
+    requestSetting: promptForSetting,
+    settings: loadSettings(workingDir).merged,
+  });
+  await extensionManager.loadExtensions();
+
+  try {
+    if (args.scope?.toLowerCase() === 'workspace') {
+      await extensionManager.enableExtension(args.name, SettingScope.Workspace);
+    } else {
+      await extensionManager.enableExtension(args.name, SettingScope.User);
+    }
+
+    // Auto-enable any disabled MCP servers for this extension
+    const extension = extensionManager
+      .getExtensions()
+      .find((e) => e.name === args.name);
+
+    if (extension?.mcpServers) {
+      const mcpEnablementManager = McpServerEnablementManager.getInstance();
+      const enabledServers = await mcpEnablementManager.autoEnableServers(
+        Object.keys(extension.mcpServers ?? {}),
+      );
+
+      for (const serverName of enabledServers) {
+        debugLogger.log(
+          `MCP server '${serverName}' was disabled - now enabled.`,
+        );
+      }
+      // Note: No restartServer() - CLI exits immediately, servers load on next session
+    }
+
+    if (args.scope) {
+      debugLogger.log(
+        `Extension "${args.name}" successfully enabled for scope "${args.scope}".`,
+      );
+    } else {
+      debugLogger.log(
+        `Extension "${args.name}" successfully enabled in all scopes.`,
+      );
+    }
+  } catch (error) {
+    throw new FatalConfigError(getErrorMessage(error));
+  }
+}
+
+export const enableCommand: CommandModule = {
+  command: 'enable [--scope] <name>',
+  describe: 'Enables an extension.',
+  builder: (yargs) =>
+    yargs
+      .positional('name', {
+        describe: 'The name of the extension to enable.',
+        type: 'string',
+      })
+      .option('scope', {
+        describe:
+          'The scope to enable the extension in. If not set, will be enabled in all scopes.',
+        type: 'string',
+      })
+      .check((argv) => {
+        if (
+          argv.scope &&
+          !Object.values(SettingScope)
+            .map((s) => s.toLowerCase())
+            .includes(argv.scope.toLowerCase())
+        ) {
+          throw new Error(
+            `Invalid scope: ${argv.scope}. Please use one of ${Object.values(
+              SettingScope,
+            )
+              .map((s) => s.toLowerCase())
+              .join(', ')}.`,
+          );
+        }
+        return true;
+      }),
+  handler: async (argv) => {
+    await handleEnable({
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      name: argv['name'] as string,
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+      scope: argv['scope'] as string,
+    });
+    await exitCli();
+  },
+};

packages/cli/src/commands/extensions/examples/custom-commands/.gitignore

@@ -0,0 +1,26 @@
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-error.log
+yarn-debug.log
+
+# Build output
+dist/
+
+# OS metadata
+.DS_Store
+Thumbs.db
+
+# TypeScript
+*.tsbuildinfo
+
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDEs
+.vscode/
+.idea/

packages/cli/src/commands/extensions/examples/custom-commands/commands/fs/grep-code.toml

@@ -0,0 +1,6 @@
+prompt = """
+Please summarize the findings for the pattern `{{args}}`.
+
+Search Results:
+!{grep -r {{args}} .}
+"""

packages/cli/src/commands/extensions/examples/custom-commands/gemini-extension.json

@@ -0,0 +1,4 @@
+{
+  "name": "custom-commands",
+  "version": "1.0.0"
+}

packages/cli/src/commands/extensions/examples/exclude-tools/.gitignore

@@ -0,0 +1,26 @@
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-error.log
+yarn-debug.log
+
+# Build output
+dist/
+
+# OS metadata
+.DS_Store
+Thumbs.db
+
+# TypeScript
+*.tsbuildinfo
+
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDEs
+.vscode/
+.idea/

packages/cli/src/commands/extensions/examples/exclude-tools/gemini-extension.json

@@ -0,0 +1,5 @@
+{
+  "name": "excludeTools",
+  "version": "1.0.0",
+  "excludeTools": ["run_shell_command(rm -rf)"]
+}

packages/cli/src/commands/extensions/examples/hooks/.gitignore

@@ -0,0 +1,26 @@
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-error.log
+yarn-debug.log
+
+# Build output
+dist/
+
+# OS metadata
+.DS_Store
+Thumbs.db
+
+# TypeScript
+*.tsbuildinfo
+
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDEs
+.vscode/
+.idea/

packages/cli/src/commands/extensions/examples/hooks/gemini-extension.json

@@ -0,0 +1,4 @@
+{
+  "name": "hooks-example",
+  "version": "1.0.0"
+}

packages/cli/src/commands/extensions/examples/hooks/hooks/hooks.json

@@ -0,0 +1,14 @@
+{
+  "hooks": {
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "node ${extensionPath}/scripts/on-start.js"
+          }
+        ]
+      }
+    ]
+  }
+}

packages/cli/src/commands/extensions/examples/hooks/scripts/on-start.js

@@ -0,0 +1,8 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+console.log(
+  'Session Started! This is running from a script in the hooks-example extension.',
+);

packages/cli/src/commands/extensions/examples/mcp-server/.gitignore

@@ -0,0 +1,26 @@
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-error.log
+yarn-debug.log
+
+# Build output
+dist/
+
+# OS metadata
+.DS_Store
+Thumbs.db
+
+# TypeScript
+*.tsbuildinfo
+
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDEs
+.vscode/
+.idea/

packages/cli/src/commands/extensions/examples/mcp-server/README.md

@@ -0,0 +1,35 @@
+# MCP Server Example
+
+This is a basic example of an MCP (Model Context Protocol) server used as a
+Gemini CLI extension. It demonstrates how to expose tools and prompts to the
+Gemini CLI.
+
+## Description
+
+The contents of this directory are a valid MCP server implementation using the
+`@modelcontextprotocol/sdk`. It exposes:
+
+- A tool `fetch_posts` that mock-fetches posts.
+- A prompt `poem-writer`.
+
+## Structure
+
+- `example.js`: The main server entry point.
+- `gemini-extension.json`: The configuration file that tells Gemini CLI how to
+  use this extension.
+- `package.json`: Helper for dependencies.
+
+## How to Use
+
+1.  Navigate to this directory:
+
+    ```bash
+    cd packages/cli/src/commands/extensions/examples/mcp-server
+    ```
+
+2.  Install dependencies:
+    ```bash
+    npm install
+    ```
+
+This example is typically used by `gemini extensions new`.

packages/cli/src/commands/extensions/examples/mcp-server/example.js

@@ -0,0 +1,60 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
+import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
+import { z } from 'zod';
+
+const server = new McpServer({
+  name: 'prompt-server',
+  version: '1.0.0',
+});
+
+server.registerTool(
+  'fetch_posts',
+  {
+    description: 'Fetches a list of posts from a public API.',
+    inputSchema: z.object({}).shape,
+  },
+  async () => {
+    const apiResponse = await fetch(
+      'https://jsonplaceholder.typicode.com/posts',
+    );
+    const posts = await apiResponse.json();
+    const response = { posts: posts.slice(0, 5) };
+    return {
+      content: [
+        {
+          type: 'text',
+          text: JSON.stringify(response),
+        },
+      ],
+    };
+  },
+);
+
+server.registerPrompt(
+  'poem-writer',
+  {
+    title: 'Poem Writer',
+    description: 'Write a nice haiku',
+    argsSchema: { title: z.string(), mood: z.string().optional() },
+  },
+  ({ title, mood }) => ({
+    messages: [
+      {
+        role: 'user',
+        content: {
+          type: 'text',
+          text: `Write a haiku${mood ? ` with the mood ${mood}` : ''} called ${title}. Note that a haiku is 5 syllables followed by 7 syllables followed by 5 syllables `,
+        },
+      },
+    ],
+  }),
+);
+
+const transport = new StdioServerTransport();
+await server.connect(transport);

packages/cli/src/commands/extensions/examples/mcp-server/gemini-extension.json

@@ -0,0 +1,11 @@
+{
+  "name": "mcp-server-example",
+  "version": "1.0.0",
+  "mcpServers": {
+    "nodeServer": {
+      "command": "node",
+      "args": ["${extensionPath}${/}example.js"],
+      "cwd": "${extensionPath}"
+    }
+  }
+}

packages/cli/src/commands/extensions/examples/mcp-server/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "mcp-server-example",
+  "version": "1.0.0",
+  "description": "Example MCP Server for Gemini CLI Extension",
+  "type": "module",
+  "main": "example.js",
+  "dependencies": {
+    "@modelcontextprotocol/sdk": "1.23.0",
+    "zod": "3.22.4"
+  }
+}

packages/cli/src/commands/extensions/examples/policies/README.md

@@ -0,0 +1,41 @@
+# Policy engine example extension
+
+This extension demonstrates how to contribute security rules and safety checkers
+to the Gemini CLI Policy Engine.
+
+## Description
+
+The extension uses a `policies/` directory containing `.toml` files to define:
+
+- A rule that requires user confirmation for `rm -rf` commands.
+- A rule that denies searching for sensitive files (like `.env`) using `grep`.
+- A safety checker that validates file paths for all write operations.
+
+## Structure
+
+- `gemini-extension.json`: The manifest file.
+- `policies/`: Contains the `.toml` policy files.
+
+## How to use
+
+1.  Link this extension to your local Gemini CLI installation:
+
+    ```bash
+    gemini extensions link packages/cli/src/commands/extensions/examples/policies
+    ```
+
+2.  Restart your Gemini CLI session.
+
+3.  **Observe the policies:**
+    - Try asking the model to delete a directory: The policy engine will prompt
+      you for confirmation due to the `rm -rf` rule.
+    - Try asking the model to search for secrets: The `grep` rule will deny the
+      request and display the custom deny message.
+    - Any file write operation will now be processed through the `allowed-path`
+      safety checker.
+
+## Security note
+
+For security, Gemini CLI ignores any `allow` decisions or `yolo` mode
+configurations contributed by extensions. This ensures that extensions can
+strengthen security but cannot bypass user confirmation.

packages/cli/src/commands/extensions/examples/policies/gemini-extension.json

@@ -0,0 +1,5 @@
+{
+  "name": "policy-example",
+  "version": "1.0.0",
+  "description": "An example extension demonstrating Policy Engine support."
+}

packages/cli/src/commands/extensions/examples/policies/policies/policies.toml

@@ -0,0 +1,28 @@
+# Example Policy Rules for Gemini CLI Extension
+#
+# Extensions run in Tier 2 (Extension Tier).
+# Security Note: 'allow' decisions and 'yolo' mode configurations are ignored.
+
+# Rule: Always ask the user before running a specific dangerous shell command.
+[[rule]]
+toolName = "run_shell_command"
+commandPrefix = "rm -rf"
+decision = "ask_user"
+priority = 100
+
+# Rule: Deny access to sensitive files using the grep tool.
+[[rule]]
+toolName = "grep_search"
+argsPattern = "(\.env|id_rsa|passwd)"
+decision = "deny"
+priority = 200
+denyMessage = "Access to sensitive credentials or system files is restricted by the policy-example extension."
+
+# Safety Checker: Apply path validation to all write operations.
+[[safety_checker]]
+toolName = ["write_file", "replace"]
+priority = 300
+[safety_checker.checker]
+type = "in-process"
+name = "allowed-path"
+required_context = ["environment"]