chore(a2a-server): if a2a task creation fails return error to user (#8106)

Co-authored-by: cornmander <shikhman@google.com>

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

@@ -36,6 +36,7 @@ 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.
@@ -116,8 +117,8 @@ export class CoderAgentExecutor implements AgentExecutor {
 
     const agentSettings = persistedState._agentSettings;
     const config = await this.getConfig(agentSettings, sdkTask.id);
-    const contextId =
-      (metadata['_contextId'] as string) || (sdkTask.contextId as string);
+    const contextId: string =
+      (metadata['_contextId'] as string) || sdkTask.contextId;
     const runtimeTask = await Task.create(
       sdkTask.id,
       contextId,
@@ -280,10 +281,10 @@ export class CoderAgentExecutor implements AgentExecutor {
     const sdkTask = requestContext.task as SDKTask | undefined;
 
     const taskId = sdkTask?.id || userMessage.taskId || uuidv4();
-    const contextId =
+    const contextId: string =
       userMessage.contextId ||
       sdkTask?.contextId ||
-      sdkTask?.metadata?.['_contextId'] ||
+      (sdkTask?.metadata?.['_contextId'] as string) ||
       uuidv4();
 
     logger.info(
@@ -381,12 +382,21 @@ export class CoderAgentExecutor implements AgentExecutor {
       const agentSettings = userMessage.metadata?.[
         'coderAgent'
       ] as AgentSettings;
-      wrapper = await this.createTask(
-        taskId,
-        contextId as string,
-        agentSettings,
-        eventBus,
-      );
+      try {
+        wrapper = await this.createTask(
+          taskId,
+          contextId,
+          agentSettings,
+          eventBus,
+        );
+      } catch (error) {
+        logger.error(
+          `[CoderAgentExecutor] Error creating task ${taskId}:`,
+          error,
+        );
+        pushTaskStateFailed(error, eventBus, taskId, contextId);
+        return;
+      }
       const newTaskSDK = wrapper.toSDKTask();
       eventBus.publish({
         ...newTaskSDK,

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

@@ -108,9 +108,10 @@ export async function loadConfig(
     logger.info('[Config] Using Gemini API Key');
     await config.refreshAuth(AuthType.USE_GEMINI);
   } else {
-    logger.error(
-      `[Config] Unable to set GeneratorConfig. Please provide a GEMINI_API_KEY or set USE_CCPA.`,
-    );
+    const errorMessage =
+      '[Config] Unable to set GeneratorConfig. Please provide a GEMINI_API_KEY or set USE_CCPA.';
+    logger.error(errorMessage);
+    throw new Error(errorMessage);
   }
 
   return config;

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

@@ -7,14 +7,17 @@
 import { describe, it, expect, beforeAll, afterAll, vi } from 'vitest';
 import request from 'supertest';
 import type express from 'express';
-import { createApp, updateCoderAgentCardUrl } from './app.js';
 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 { TaskMetadata } from '../types.js';
 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 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', () => ({
@@ -56,6 +59,16 @@ vi.mock('../agent/task.js', () => {
   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;

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

@@ -0,0 +1,52 @@
+/**
+ * @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 } from '../types.js';
+import 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,
+    },
+  });
+}