feat(a2a): Introduce /init command for a2a server (#13419)

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

@@ -5,6 +5,7 @@
  */
 
 import { ExtensionsCommand } from './extensions.js';
+import { InitCommand } from './init.js';
 import { RestoreCommand } from './restore.js';
 import type { Command } from './types.js';
 
@@ -14,6 +15,7 @@ class CommandRegistry {
   constructor() {
     this.register(new ExtensionsCommand());
     this.register(new RestoreCommand());
+    this.register(new InitCommand());
   }
 
   register(command: Command) {

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

@@ -0,0 +1,182 @@
+/**
+ * @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 } 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 type { CommandActionReturn, Config } from '@google/gemini-cli-core';
+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', () => ({
+  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 +1,168 @@
+/**
+ * @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.');
+    }
+    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/types.ts

@@ -4,11 +4,14 @@
  * 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 {
@@ -24,6 +27,7 @@ export interface Command {
   readonly subCommands?: Command[];
   readonly topLevel?: boolean;
   readonly requiresWorkspace?: boolean;
+  readonly streaming?: boolean;
 
   execute(
     config: CommandContext,